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Chapter 2 Study Guide

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Chapter 2 study guide
 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
Atoms are composed of
a.
 protons with a positive charge.
b.
 neutrons with no charge.
c.
 electrons with a negative charge.
d.
 All of the above
 2.
The smallest particle of carbon that can retain the chemical properties of carbon is
a.
 a carbon molecule.
b.
 a carbon macromolecule.
c.
 a carbon atom.
d.
 the nucleus of a carbon atom.
 3.
A substance that is composed of only one type of atom is called a(n)
a.
 nucleus.
c.
 element.
b.
 cell.
d.
 molecule.
 4.
All matter in the universe is composed of
a.
 cells.
c.
 atoms.
b.
 molecules.
d.
 carbon.
 5.
The electrons of an atom
a.
 are found in the nucleus along with the protons.
b.
 orbit the nucleus in various energy levels.
c.
 have a positive charge.
d.
 are attracted to the positive charge of neutrons.
 6.
Atoms that have gained energy
a.
 have protons and neutrons that move farther apart.
b.
 lose neutrons from the nucleus.
c.
 have electrons that move to higher energy levels.
d.
 absorb electrons into the nucleus.
 7.
Which of the following states of matter contain(s) particles that are tightly linked together in a definite shape?
a.
 solid
c.
 gas
b.
 liquid
d.
 solid and liquid
 8.
Because carbon has four electrons in its outer energy level,
a.
 it can form bonds with carbon atoms only.
b.
 these atoms are naturally chemically stable.
c.
 it can react with up to four other atoms to form covalent bonds.
d.
 it cannot react with anything other than organic molecules.
 9.
The bond formed when two atoms share a pair of electrons is called a
a.
 hydrogen bond.
c.
 covalent bond.
b.
 nonpolar bond.
d.
 water bond.
 10.
Sharing of electrons between atoms of two or more elements
a.
 results in the formation of an ion.
b.
 results in the formation of a compound.
c.
 results in the formation of noble gases.
d.
 results in destabilization of the atoms involved.
 11.
An atom that has gained or lost electrons is called a(n)
a.
 molecule.
c.
 ion.
b.
 nucleon.
d.
 element.
 12.
Which of the following statements most accurately describes the difference between an ionic bond and a covalent bond?
a.
 Atoms held together by ionic bonds separate when placed in water, while atoms held together by covalent bonds do not separate in water.
b.
 Ionic bonds hold together atoms of two different types, while covalent bonds hold together atoms of the same type.
c.
 Electrons are exchanged between atoms held together by an ionic bond, but they are shared between atoms held together by a covalent bond.
d.
 Ionic bonds form between atoms that carry opposite charges, while covalent bonds form between uncharged atoms.
nar001-1.jpg
 13.
Refer to the graph above. Reaction 1 in the graph
a.
 is an energy-storing reaction.
b.
 requires a greater activation energy than reaction 2.
c.
 may use the same initial reactant condition needed to form product Y.
d.
 All of the above
 14.
Refer to the graph above. Reaction 3 in the graph
a.
 probably occurred in the presence of a catalyst.
b.
 requires a greater activation energy than reaction 2.
c.
 is the same as reaction 1, but faster.
d.
 takes longer than reaction 2.
 15.
Refer to the graph above. Which of these statements regarding the graph is true?
a.
 Reaction 2 occurs faster than reaction 3 because reaction 2 requires more energy than reaction 3.
b.
 The difference in the graphs shown for reaction 2 and reaction 3 is due to a difference in the activation energy needed for these reactions.
c.
 Reactant X contains more energy at the beginning of the reaction than product Z has after the reaction.
d.
 All of the above
 16.
Changing the course or pathway of a chemical reaction so that it requires less activation energy
a.
 is a violation of the laws of nature.
b.
 requires higher temperatures than those found within cells.
c.
 occurs only when reactants are quickly added to the reaction mixture.
d.
 is accomplished by the action of catalysts on reactants.
 17.
Enzymes
a.
 are able to heat up molecules so that they can react.
b.
 provide CO2 for chemical reactions.
c.
 are biological catalysts.
d.
 absorb excess heat so that reactions occur at low temperatures.
 18.
A single organism may contain
a.
 thousands of different enzymes, each one specific to a different chemical reaction.
b.
 one enzyme that plays a role in thousands of different chemical reactions.
c.
 approximately 100 kinds of enzymes, each one specific to a different chemical reaction.
d.
 one enzyme that is specific to photosynthesis and one enzyme that is specific to cellular respiration.
 19.
When a molecule gains an electron, it has been
a.
 oxidized.
c.
 digested.
b.
 reduced.
d.
 inactivated.
 20.
Oxidation-reduction reactions are important in organisms because they
a.
 allow the passage of energy from molecule to molecule.
b.
 prevent nuclear reactions from occurring.
c.
 allow the creation and destruction of energy.
d.
 None of the above; oxidation-reduction reactions do not occur in living organisms.
 21.
The concentration of a solution is
a.
 the number of particles of a substance in a solvent.
b.
 the amount of a solvent that is dissolved in a fixed amount of a solution.
c.
 the amount of a solute that is dissolved in a fixed amount of a solution.
d.
 the ratio of solute to solvent in a solution.
 22.
A neutral solution has an equal number of
a.
 hydrogen and hydronium ions.
b.
 hydroxide and hydronium ions.
c.
 hydrogen and hydroxide ions.
d.
 oxygen and hydrogen ions.
 23.
The terms base and alkaline refer to solutions that
a.
 contain dissolved sodium hydroxide.
b.
 contain more hydronium ions than hydroxide ions.
c.
 contain more hydroxide ions than hydronium ions.
d.
 contain more hydroxide ions than hydrogen ions.
 24.
A solution with a pH of 11 is
a.
 acidic.
c.
 neutral.
b.
 alkaline.
d.
 a buffer.
 25.
Acidic solutions have a pH that is
a.
 less than 7.
c.
 a negative number.
b.
 between 0 and 14.
d.
 more than 7.
 26.
Buffers
a.
 are of relatively little importance in living things.
b.
 are formed when a large number of hydroxide ions are released in a solution.
c.
 are formed when a large number of hydronium ions are released in a solution.
d.
 tend to prevent great fluctuations in pH.
 27.
Atoms become more stable when they form compounds because
a.
 they always lose electrons when they form compounds.
b.
 their outer orbitals become filled when they form compounds.
c.
 they always gain electrons when they form compounds.
d.
 their nucleus loses extra protons when they form compounds.
 28.
A water molecule is polar because its hydrogen and oxygen atoms
a.
 both lose electrons.
b.
 become ions.
c.
 both gain electrons.
d.
 do not share the electrons equally.
 29.
Polar molecules such as water have
a.
 no negative or positive poles.
b.
 both negative and positive poles.
c.
 only a negative pole.
d.
 only a positive pole.
 30.
A molecule that has a partial positive charge on one side and a partial negative charge on the other side is called a
a.
 nonpolar molecule.
c.
 charged molecule.
b.
 polar molecule.
d.
 bipolar molecule.
 31.
Water is a polar molecule because
a.
 it contains two hydrogen atoms for each oxygen atom.
b.
 it has a charge.
c.
 different parts of the molecule have slightly different charges.
d.
 it does not have a charge.
 32.
Water molecules break up other polar substances
a.
 such as salts.
b.
 because of the uneven charge distribution that exists in water molecules.
c.
 thus freeing ions in these substances for use by the body.
d.
 All of the above
 33.
Which of the following characteristics of water is not a result of hydrogen bonding?
a.
 adhesive strength
b.
 capillarity
c.
 cohesive strength
d.
 All of the above are a result of hydrogen bonding.
 

Completion
Complete each statement.
 34.
Substances that are changed when they become involved in chemical reactions are called ____________________, while the new substances that are formed are called ____________________.
 35.
The energy needed to break existing chemical bonds during the initiation of a chemical reaction is called ____________________.
 36.
Chemical reactions in the body can be speeded up by adding a(n) ____________________, which lowers the amount of activation energy required to start the reaction.
 37.
The loss of electrons from a molecule is called ____________________, while the gain of electrons by a molecule is called ____________________.
 38.
A substance that dissolves in another is called a(n) ____________________.
 39.
____________________ is the most common solvent in cells.
 40.
____________________ and ____________________ ions form when water dissociates.
 41.
An acidic solution is one that has more ____________________ than ____________________ ions.
 42.
A solution with a pH of 3 has ____________________ times more hydronium ions than a solution with a pH of 6.
 43.
Buffers are important because body fluids must be maintained within a relatively narrow range of ____________________.
 44.
Water is very effective at dissolving other polar substances because of its ____________________.
 45.
Breaking of ____________________ bonds is the first thing that happens when water is heated, which means that it takes a great deal of thermal energy to raise the temperature of water.
 

Problem
 46.

pr046-1.jpg

Refer to the illustration above. The graph depicts the relative energy levels of the products and reactants for the following chemical reaction: A + B C + D. Write your answers to the following in the spaces below.

a.      Which substances, A, B, C, and/or D, are present at point 1 on the graph?
b.      Which substances, A, B, C, and/or D, are present at point 3 on the graph?
c.      Why is point 2 at a higher energy level than point 1?
d.      Why is point 3 at a lower energy level than point 1?
e.      Draw a dashed line on the graph indicating how the energy level of this reaction over time would be different if the enzyme that catalyzes the reaction were not present.
 

Essay
 47.
Plant growers often use sprinkler irrigation to protect crops they are growing from frost damage. The water that lands on the leaves turns to ice. How does this protect the plants from frost damage? Write your answer in the space below.
 48.
Define enzyme, and describe how an enzyme can function in speeding up a chemical reaction within a cell. Write your answer in the space below.
 49.
How does water’s polar nature affect its ability to dissolve different substances? Write your answer in the space below.
 50.
Explain the relationship between hydrogen bonding and the observation that a full sealed bottle of water breaks when it freezes. Write your answer in the space below.

 
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Chapter 1 Introduction

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Chapter 1 Introduction
 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
Biology is the study of
a.
 minerals.
c.
 the weather.
b.
 life.
d.
 energy.
 2.
All organisms possess DNA. DNA
a.
 creates energy for cells.
b.
 allows sensitivity to environmental stimuli.
c.
 contains information for growth and development.
d.
 captures energy from the sun.
 3.
Instructions for traits that are passed from parents to offspring are known as
a.
 a species plan.
c.
 genes.
b.
 organ codes.
d.
 natural selections.
 4.
Homeostasis means
a.
 a change over long periods of time.
b.
 keeping things the same.
c.
 rapid change.
d.
 the same thing as evolution.
 5.
Ecology
a.
 refers to change in species over time.
b.
 refers to a delicate internal balance within organisms.
c.
 is inconsistent with evolution.
d.
 is the study of communities or organisms in relation to their environment.
 6.
Which of the following is not necessarily a characteristic of living things?
a.
 homeostasis
c.
 complexity
b.
 metabolism
d.
 reproduction
 7.
The smallest units that can carry on all the functions of life are called
a.
 molecules.
c.
 organelles.
b.
 cells.
d.
 species.
 8.
Living things
a.
 need energy for life processes.
b.
 have the ability to reproduce.
c.
 are composed of cells.
d.
 All of the above
 9.
All organisms are composed of
a.
 diatoms.
c.
 cells.
b.
 cellulose.
d.
 None of the above
 10.
All living things maintain a balance within their cells and the environment through the process of
a.
 growth.
c.
 homeostasis.
b.
 development.
d.
 evolution.
 11.
Which of the following is a characteristic of all living things?
a.
 movement
c.
 development
b.
 photosynthesis
d.
 cellular organization
 12.
Which of the following is not a partial explanation for our lack of understanding of many of the living things on Earth?
a.
 Many organisms are microscopic in size and therefore difficult to observe.
b.
 Many organisms are so different from other organisms that it is difficult to understand them.
c.
 Many organisms live in areas of the world that are difficult to explore.
d.
 Tropical rain forests contain many species, and it is difficult to find all of them in these dense forests.
 13.
A scientist noticed that in acidic pond water some salamanders developed with curved spines. This was a(n)
a.
 hypothesis.
c.
 observation.
b.
 theory.
d.
 control.
 14.
Which example of scientific methodology is incorrect?
a.
 observation—a number of people in a certain place dying of a disease outbreak
b.
 measurement—a record of the number of people with symptoms of a disease and the number of people who had died from the disease
c.
 analysis of data—comparison of the effects of mixing monkey cells with virus-containing blood in test tubes and the effects of mixing liquid from these test tubes with fresh monkey cells
d.
 inference making—identification of the Ebola virus as the cause of a disease by taking electron micrographs of substances found in the blood of persons affected with the disease
 15.
The English physician Ronald Ross wanted to try to find the cause of malaria. Based on his observations, Dr. Ross suggested that the Anopheles mosquito might spread malaria from person to person. This suggestion was a
a.
 prediction.
c.
 theory.
b.
 hypothesis.
d.
 scientific “truth.”
 16.
The English physician Ronald Ross knew that the parasite Plasmodium was always found in the blood of malaria patients. He thought that if the Anopheles mosquitoes were responsible for spreading malaria, then Plasmodium would be found in the mosquitoes. This idea was a
a.
 prediction.
c.
 theory.
b.
 hypothesis.
d.
 scientific “truth.”
 17.
Scientific hypotheses are most often tested by the process of
a.
 communicating.
c.
 experimenting.
b.
 inferring.
d.
 analyzing data.
 18.
A hypothesis is
a.
 a definite answer to a given problem.
b.
 a testable possible explanation of an observation.
c.
 a proven statement.
d.
 a concluding statement.
 19.
A unifying explanation for a broad range of observations is a
a.
 hypothesis.
c.
 prediction.
b.
 theory.
d.
 controlled experiment.
 20.
A hypothesis that does not explain an observation
a.
 is known as an inaccurate forecast.
b.
 often predicts a different observation.
c.
 is rejected.
d.
 None of the above
 21.
Scientists usually design experiments
a.
 with a good idea of the expected experimental results.
b.
 based on wild guesses.
c.
 in order to develop new laboratory tools.
d.
 All of the above
 22.
A scientific theory
a.
 is absolutely certain.
b.
 is unchangeable.
c.
 may be revised as new evidence is presented.
d.
 is a controlled experiment.
 23.
The word theory used in a scientific sense means
a.
 a highly tested, generally accepted principle.
b.
 a guess made with very little knowledge to support it.
c.
 an absolute scientific certainty.
d.
 None of the above
 24.
observation : hypothesis ::
a.
 theory : observation
c.
 hypothesis : experiment
b.
 guess : hypothesis
d.
 theory : control
 25.
Which of the following components of a scientific investigation would benefit from communication between scientists?
a.
 observing
c.
 analyzing data
b.
 measuring
d.
 All of the above
 26.
Typically, the order in which the steps of the scientific method are applied is
a.
 observations, predictions, hypothesis, controlled testing, theory, verification.
b.
 predictions, observations, hypothesis, theory, controlled testing, verification.
c.
 observations, hypothesis, predictions, controlled testing, theory, verification.
d.
 observations, hypothesis, predictions, controlled testing, verification, theory.
 27.
A light microscope that has an objective lens of 10 and an ocular lens of 20 has a magnification of
a.
 30.
c.
 300.
b.
 200.
d.
 2000.
 28.
Which of the following is not a correct association between an SI base unit abbreviation and its base quantity?
a.
 A—area
b.
 m—length
c.
 s—time
d.
 mol—amount of a substance
 29.
Which of the following is not an example of good laboratory practice?
a.
 working alone in the lab
b.
 asking permission before using equipment
c.
 working with a partner in the lab
d.
 wearing goggles in the lab
 30.
Scientists share their research results by
a.
 publishing in scientific journals.
b.
 presenting at scientific meetings.
c.
 avoiding conflicts of interest.
d.
 Both a and b
 

Completion
Complete each statement.
 31.
____________________ is the study of the interaction of organisms with their environment and with each other.
 32.
To function properly, all living things must maintain a constant internal environment through the process of ____________________.
 33.
An educated guess, or a(n) ____________________, may be tested by experimentation.
 34.
Stating in advance the result that may be obtained from testing a hypothesis is called ____________________.
 35.
A unifying explanation for a broad range of observations is a ____________________.
 36.
A ____________________ experiment is one in which the condition suspected to cause the effect is compared to the same situation without the suspected condition.
 37.
The base unit for length in the Système International d’Unités (International System of Units) is the ____________________.
 38.
A ____________________ electron microscope passes a beam of electrons over a specimen’s surface, whereas a ____________________ electron microscope passes a beam of electrons through a thin slice of a specimen.
 

Problem
 39.
Some scientists conducted an experiment in which they evaluated various measurements of human health in people who drank at least one cup of coffee a day. They found no significant differences in these health indicators between the subjects who drank only one cup of coffee a day and those who drank as many as 20 cups a day. They concluded that coffee has no adverse effects on human health. Write your answers to the following in the spaces below.
a. What were the independent and dependent variables in this experiment?
b. Was this a controlled experiment? If so, what were the control and experimental groups?
c. Do you agree with the conclusion the scientists drew from their results? Why or why not?
 

Essay
 40.
Briefly discuss some of the major themes in biology that we will examine this year. Write your answer in the space below.
 41.
Name five characteristics that are considered distinct properties of all living things. Write your answer in the space below.
 42.
Toads that live in hot, dry regions bury themselves in the soil during the day. How might this be important to the toad? Write your answer in the space below.
 43.
The results of an experiment do not support the hypothesis that the experiment was designed to test. Was the experiment a waste of time? Explain. Write your answer in the space below.
 44.
Why is it important to study biology even if you are not planning a career in biology? Write your answer in the space below.

 
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Cell Reproduction

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Cell Reproduction

 

 

Modified True/False
Indicate whether the statement is true or false.  If false, change the identified word or phrase to make the statement true.
 1.
A gene is a segment of DNA that directs the production of RNA and protein. _________________________
 2.
The information needed by a cell to direct its activities and to determine its characteristics is contained in molecules of protein. _________________________
 3.
After the replication of a cell’s DNA, there are twice as many centromeres as there are chromatids. _________________________
 4.
Cells that seldom divide spend most of their time in interphase. _________________________
 5.
After mitosis and interphase, each new cell has a complete set of the parent cell’s chromosomes. _________________________
 6.
In animal cells, cytokinesis results when a cell plate forms across the cell to divide the cytoplasm. _________________________
 7.
Plant cells separate their cytoplasm during cytokinesis when protein threads pinch the cell in half. _________________________
 8.
The cell cycle has four checkpoints that act to inhibit uncontrolled cell division. _________________________
 9.
Offspring formed by asexual reproduction look exactly like their parent. _________________________
 10.
In budding, new individuals develop from pieces of the original individual. _________________________
 11.
Some eukaryotes reproduce asexually, and some produce sexually. _________________________
 12.
In asexual reproduction, two parents each pass genetic material to their offspring. _________________________
 13.
Asexual reproduction provides for genetic diversity, the raw material for evolution. _________________________
 14.
Genetic diversity is the raw material for evolution. _________________________
 15.
Genes on chromosomes are the units of inheritance. _________________________
 16.
Each human somatic cell contains two copies of each chromosome for a total of 23 chromosomes. _________________________
 17.
Gametes are diploid so that when fertilization occurs, the resulting zygote will have the characteristic number of chromosomes for that species. _________________________
 18.
While paired together during the second division of meiosis, two chromosomes may exchange segments of DNA. _________________________
 19.
Crossing-over is the exchange of corresponding portions of chromatids between homologous chromosomes. _________________________
 20.
Random fertilization refers to the fact that homologous chromosomes are distributed randomly during meiosis. _________________________
 21.
The process by which sperm are produced in male animals is called spermatogenesis. _________________________
 22.
During the diploid life cycle, all of the cells are diploid. _________________________
 23.
During the haploid life cycle, the zygote is the only diploid cell. _________________________
 24.
In the life cycle of a plant, the gametophyte is the haploid phase that produces gametes by mitosis. _________________________
 25.
A spore gives rise to a multicellular individual without joining with another cell. _________________________
 26.
Moss plants have haploid life cycles. ______________________________
 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 27.
Which of the following is not a reason cells divide?
a.
 The cell gets too big to process and transport nutrients.
b.
 New cells are needed for growth.
c.
 DNA cannot be copied quickly enough in large cells.
d.
 Surface area-to-volume ratio becomes too large.
 28.
The chromosome of a bacterium
a.
 is wrapped around proteins.
b.
 has a circular shape.
c.
 occurs in multiple pairs within the cell.
d.
 is found within the nucleus.
 29.
The region of a chromosome where two sister chromatids are held together is called a
a.
 spindle.
c.
 nucleosome.
b.
 centromere.
d.
 centriole.
 30.
Chromatids are
a.
 dense patches within the nucleus.
b.
 bacterial chromosomes.
c.
 joined strands of duplicated genetic material.
d.
 prokaryotic nuclei.
 31.
When a chromosome condenses,
a.
 a histone wraps around chromatin.
b.
 beads form on the DNA double helix.
c.
 its centromere splits.
d.
 looped domains coil into a structure.
 32.
In order to fit within a cell, DNA becomes more compact by
a.
 breaking apart into separate genes.
b.
 extending to form very long, thin molecules.
c.
 wrapping tightly around histones.
d.
 being enzymatically changed into a protein.
 33.
In a bacterium, cell division takes place when
a.
 its nucleus divides.
b.
 the cell splits into two cells, one of which receives all of the DNA.
c.
 the DNA is copied, a new cell wall forms between the DNA copies, and the cell splits into two cells.
d.
 spindle fibers form.
 34.
The phase of the cell cycle that occupies most of an average cell’s life is
a.
 G1.
c.
 G2.
b.
 mitosis.
d.
 S.
 35.
What occurs after cytokinesis is completed?
a.
 The cell organizes its microtubules.
c.
 The cell enters G1.
b.
 The cell begins to replicate its DNA.
d.
 The cell enters G2.
 36.
Which of the following shows the correct sequence of the cell cycle?
a.
 cytokinesis ® mitosis ® G1 ® S ® G2
b.
 S ® G1 ® G2 ® mitosis ® cytokinesis
c.
 G1 ® S ® G2 ® mitosis ® cytokinesis
d.
 mitosis ® G1 ® S® G2 ® cytokinesis
 37.
Cells that are not dividing remain in the
a.
 mitosis phase.
c.
 first gap phase.
b.
 synthesis phase.
d.
 second gap phase.
 38.
The synthesis (S) phase is characterized by
a.
 DNA replication.
b.
 cell division.
c.
 replication of mitochondria and other organelles.
d.
 the division of cytoplasm.
 39.
5 steps : the cell cycle ::
a.
 6 steps : prophase
c.
 3 steps : meiosis
b.
 9 steps : cytokinesis
d.
 4 steps : mitosis
 40.
The first three phases of the cell cycle are collectively known as
a.
 a gap.
c.
 mitosis.
b.
 telophase.
d.
 interphase.
 41.
cell growth : G1 ::
a.
 mitosis : cytokinesis
b.
 mitosis : meiosis
c.
 mitochondria replication : synthesis phase
d.
 DNA copying : synthesis phase
 42.
metaphase : prophase ::
a.
 G1 : mitosis
c.
 mitosis : cytokinesis
b.
 G2 : S
d.
 S : mitosis
 43.
Mitosis is the process by which
a.
 microtubules are assembled.
b.
 cytoplasm is divided.
c.
 the nucleus is divided into two nuclei.
d.
 the cell rests.
 44.
A spindle fiber is a specialized form of
a.
 microtubule.
c.
 centriole.
b.
 centrosome.
d.
 chromosome.
 45.
The phase of mitosis that is characterized by the arrangement of all chromosomes along the equator of the cell is called
a.
 telophase.
c.
 anaphase.
b.
 metaphase.
d.
 prophase.
nar001-1.jpg
 46.
Refer to the illustration above. The cell in diagram 1 is in
a.
 metaphase.
c.
 anaphase.
b.
 telophase.
d.
 prophase.
 47.
Refer to the illustration above. Mitosis begins with the stage shown in diagram
a.
 1.
c.
 3.
b.
 2.
d.
 4.
 48.
Refer to the illustration above. The cell shown in diagram 5 is in
a.
 metaphase.
c.
 anaphase.
b.
 telophase.
d.
 prophase.
nar002-1.jpg
 49.
Refer to the illustration above. Which of the following correctly indicates the order in which these events occur?
a.
 A, B, C, D
c.
 B, A, C, D
b.
 C, B, A, D
d.
 A, C, B, D
 50.
Refer to the illustration above. During which stage do the centromeres divide?
a.
 A
c.
 C
b.
 B
d.
 D
 51.
As a result of mitosis, each of the two new cells produced from the parent cell during cytokinesis
a.
 receives a few chromosomes from the parent cell.
b.
 receives an exact copy of all the chromosomes present in the parent cell.
c.
 donates a chromosome to the parent cell.
d.
 receives exactly half the chromosomes from the parent cell.
 52.
Cytokinesis in plant cells involves the formation of
a.
 a belt of protein threads.
c.
 spindle fibers.
b.
 a cell plate.
d.
 centrioles.
 53.
Which of the following statements is true?
a.
 Prokaryotes divide by mitosis.
b.
 Eukaryotes have circular chromosomes.
c.
 Animal cells form new cell walls when they divide.
d.
 Plant cells and animal cells have different strategies for cytokinesis.
 54.
In eukaryotes, the cell cycle is controlled by
a.
 proteins.
c.
 lipids.
b.
 carbohydrates.
d.
 fats.
 55.
At the G2 checkpoint, DNA replication is checked by
a.
 receptor proteins.
c.
 repair enzymes.
b.
 electron transport chains.
d.
 cell-surface markers.
 56.
The cell cycle is monitored as each cell passes through
a.
 the S phase.
c.
 the interphase checkpoint.
b.
 checkpoints.
d.
 cytokinesis.
 57.
Normal cells become cancer cells when
a.
 regulation of cell growth and division occurs.
b.
 cells respond to control mechanisms.
c.
 cells pass through G1.
d.
 cells do not respond to checkpoints.
 58.
Which of the following is not a type of asexual reproduction?
a.
 budding
c.
 binary fission
b.
 fragmentation
d.
 fertilization
 59.
Hydras reproduce by
a.
 budding.
c.
 binary fission.
b.
 fragmentation.
d.
 parthenogenesis.
 60.
Budding is an example of
a.
 endosymbiosis.
c.
 meiosis.
b.
 asexual reproduction.
d.
 sexual reproduction.
 61.
The simplest and most primitive method of reproduction is
a.
 sexual.
c.
 haploid.
b.
 diploid.
d.
 asexual.
 62.
Binary fission
a.
 occurs when two cells collide with each other.
b.
 produces excess energy.
c.
 creates new species.
d.
 is the process by which bacteria reproduce.
 63.
The process of producing offspring is called reproduction and can be
a.
 eukaryotic or prokaryotic.
c.
 zygotic or gametic.
b.
 asexual or sexual.
d.
 haploid or diploid
 64.
Sexual reproduction includes
a.
 budding.
c.
 binary fission.
b.
 fragmentation.
d.
 fertilization
 65.
Normal human males develop from fertilized eggs containing which of the following sex chromosome combinations?
a.
 XY
c.
 XO
b.
 XX
d.
 OO
 66.
Homologous chromosomes are pairs of chromosomes containing genes that code for
a.
 different traits.
c.
 DNA.
b.
 the same traits.
d.
 sex.
 67.
In humans, gametes contain
a.
 22 autosomes and 1 sex chromosome.
b.
 1 autosome and 22 sex chromosomes.
c.
 45 autosomes and 1 sex chromosome.
d.
 1 autosome and 45 sex chromosomes.
 68.
In humans, the male determines the sex of the child because males have
a.
 two X chromosomes.
c.
 two Y chromosomes.
b.
 one X and one Y chromosome.
d.
 46 chromosomes.
 69.
The X and Y chromosomes are called
a.
 extra chromosomes.
c.
 sex chromosomes.
b.
 homologous chromosomes.
d.
 autosomes.
 70.
female : XX ::
a.
 female : gametes
c.
 male : YY
b.
 female : eggs
d.
 male : XY
 71.
How many chromosomes are in the body cells of an organism that has a haploid number of 8?
a.
 4
c.
 12
b.
 8
d.
 16
 72.
The diploid number of chromosomes in a human skin cell is 46. The number of chromosomes found in a human egg cell is
a.
 46.
c.
 23.
b.
 92.
d.
 12.5.
 73.
diploid : somatic cell :: haploid :
a.
 body cell
c.
 gamete
b.
 chromosome
d.
 zygote
 74.
A haploid cell is one that
a.
 has two homologues of each chromosome.
b.
 is designated by the symbol 2n.
c.
 has chromosomes found in pairs.
d.
 has one set of chromosomes.
nar003-1.jpg
 75.
Refer to the illustration above. The process shown is
a.
 mitosis.
c.
 meiosis.
b.
 chromosomal mutation.
d.
 dominance.
 76.
Separation of homologues occurs during
a.
 mitosis.
c.
 meiosis II.
b.
 meiosis I.
d.
 fertilization.
 77.
When crossing-over takes place, chromosomes
a.
 mutate in the first division.
b.
 produce new genes.
c.
 decrease in number.
d.
 exchange corresponding segments of DNA.

Using the information you have learned about cell reproduction, infer answers to the questions below about a cell with a diploid number of 4 chromosomes. Select from among the diagrams below, labeled A, B, C, D, and E, to answer the questions.

nar004-1.jpg
 78.
Which of the diagrams above depicts a cell at the end of meiosis I?
a.
 B
c.
 D
b.
 C
d.
 E
 79.
Which of the diagrams above depicts a cell at the end of meiosis II?
a.
 A
c.
 C
b.
 B
d.
 D
 80.
Which of the diagrams above depicts a cell at the beginning of mitosis?
a.
 B
c.
 D
b.
 C
d.
 E
 81.
Which of the diagrams above depicts a cell at the end of mitosis?
a.
 A
c.
 C
b.
 B
d.
 D
 82.
The difference between anaphase of mitosis and anaphase I of meiosis is that
a.
 the chromosomes line up at the equator in anaphase I.
b.
 centromeres do not exist in anaphase I.
c.
 chromatids do not separate at the centromere in anaphase I.
d.
 crossing-over occurs only in anaphase of mitosis.
 83.
The exchange of segments of DNA between the members of a pair of chromosomes
a.
 ensures that variations within a species never occur.
b.
 acts as a source of variations within a species.
c.
 always produces genetic disorders.
d.
 is called genetic crossing.
 84.
Crossing-over occurs
a.
 during prophase II.
c.
 during prophase I.
b.
 during fertilization.
d.
 at the centromere.
 85.
Which of the following does not provide new genetic combinations?
a.
 random fertilization
c.
 independent assortment
b.
 cytokinesis
d.
 crossing-over
 86.
During cytokinesis in the female, what divides unequally?
a.
 the sperm cell
c.
 the cytoplasm
b.
 the ovary
d.
 the DNA
 87.
The more common name for an ovum is a(n)
a.
 egg.
c.
 nutrient.
b.
 hormone.
d.
 polar body.
 88.
To create new haploid cells during the haploid life cycle, the zygote undergoes
a.
 mitosis.
c.
 fusion.
b.
 fertilization.
d.
 meiosis.
 89.
Which of the following is not a type of sexual life cycle?
a.
 alternation of generations
c.
 diploid
b.
 haploid
d.
 parthenogenesis
 90.
In alternation of generations, a diploid spore-forming cell gives rise to four
a.
 zygotes.
c.
 haploid spores.
b.
 sperm cells.
d.
 diploid spores.
 91.
During alternation of generations, cells reproduce by
a.
 meiosis only.
c.
 both meiosis and mitosis.
b.
 mitosis only.
d.
 binary fission.
 

Completion
Complete each statement.
 92.
Growth occurs through cell enlargement and cell ____________________.
 93.
The DNA in eukaryotic cells is packaged into structures called ____________________.
 94.
A duplicated chromosome consists of two identical ____________________, which are held together at the centromere.
 95.
The sequence of events that occurs in a cell from one cell division to the next is called the ____________________.
 96.
Collectively, the time spent in G1 + S + G2 is called ____________________.
 97.
A cell’s DNA is copied during the ____________________ phase.
 98.
Cells that are not dividing remain in the ____________________ phase.
 99.
Spindle fibers are made of hollow tubes of protein called ____________________.
 100.
The spindle is assembled by the ____________________.
 101.
In most eukaryotic cells, ____________________ takes place after the nucleus divides.
 102.
In plant cells, a(n) ____________________ forms in the center of the cell during cytokinesis.
 103.
Normal cell growth and cell division are regulated by ____________________.
 104.
The cell cycle is controlled in eukaryotes at three principal ____________________.
 105.
Loss of control and regulation of the ____________________ can result in the development of cancer.
 106.
The separation of a parent into two or more individuals of about equal size is called ____________________.
 107.
Binary fission is the process by which ____________________ split asexually into two identical organisms.
 108.
Only ____________________ cells can produce gametes.
 109.
Somatic cells containing two sets of 23 chromosomes each are always ____________________.
 110.
After a new nuclear membrane forms during telophase I of meiosis, the ____________________ divides, resulting in two cells.
 111.
The process called ____________________ guarantees that the number of chromosomes in gametes is half the number of chromosomes in body cells.
 112.
Prophase I of meiosis is different from prophase of mitosis in that every chromosome pairs with its ____________________.
 113.
A reciprocal exchange of corresponding segments of DNA is called ____________________ – ____________________.
 114.
The four haploid cells formed in the male at the end of meiosis II develop tails and are called ____________________.
 115.
The diploid number of chromosomes is re-established through ____________________.
 116.
In a haploid life cycle, ____________________ results in the first cell of a multicellular haploid organism.

 
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Cells and Their Functions

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Cells and Their Functions

 

 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
The smallest unit that can carry out all activities we associate with life is:
a.
 atom.
b.
 organelle.
c.
 cell.
d.
 tissue.
e.
 organ.
 2.
What characteristic of cells could be used to determine the presence or absence of life?
a.
 presence of organic molecules
b.
 presence of inorganic molecules
c.
 alteration of concentrations of organic and/or inorganic molecules
d.
 relatively constant concentrations of organic and/or inorganic molecules
e.
 None of the above would be useful in determining the presence or absence of life.
 3.
Which of the following is not found in single celled organisms?
a.
 atoms
b.
 cells
c.
 tissues
d.
 Neither A nor B is found in single celled organisms.
e.
 Neither A, nor B, nor C is found in single celled organisms.
 4.
Evidence that all living cells have a common origin is provided by:
a.
 the cell theory, which states that the cell is the basic unit of life.
b.
 the fact that all new cells come from previously existing cells.
c.
 the fact that cells are the building blocks of the most complex plants.
d.
 basic similarities in cell structure and chemistry.
e.
 the fact that cells are the smallest units that can carry out all life activities.
 5.
As biologists continue to unlock the secrets of ________, many new doors are opening to development of medical treatments.
a.
 proteins
b.
 mitochondria
c.
 cell membranes
d.
 DNA
e.
 ribosomes
 6.
The function of the plasma membrane is to:
a.
 serve as a highly selective barrier.
b.
 completely isolate the cell from the external environment.
c.
 equalize the chemical composition inside and outside the cell.
d.
 allow cells to accumulate materials and energy.
e.
 Both A and D.
 7.
It is advantageous for cells to be small because:
a.
 a small cell size prevents a cell from weighing too much.
b.
 a small cell size occupies less space in nature where space is limited.
c.
 a small cell has a small volume relative to surface area, thereby increasing efficient transport.
d.
 a small cell has a small surface area relative to volume, thereby facilitating ion balance.
e.
 a small cell is better able to conserve energy than a larger cell.
Figure 04-01
Use the figure below to answer the corresponding questions.

nar001-1.jpg
 8.
Which of the following statements about Figure 04-01 is true?
a.
 Figure B has a greater surface area than Figure A.
b.
 Figure B has a greater volume than Figure A.
c.
 Figure B has a smaller volume than Figure A.
d.
 Figure B has a greater surface area to volume ratio than Figure A.
e.
 Figure B has a smaller surface area to volume ratio than Figure A.
 9.
Based on your knowledge of basic geometric relationships, the actual surface area to volume ratio for Figure B in Figure 04-01 is:
a.
 0.01.
b.
 0.06.
c.
 100.
d.
 1,000.
e.
 This cannot be determined from the information provided.
 10.
One strategy that allows larger cells to have an effective surface area to volume ratio is:
a.
 having a completely spherical shape.
b.
 being short and fat.
c.
 having thin, finger-like projections.
d.
 having a thinner plasma membrane.
e.
 locomotion.
 11.
Which of the following is not an example of homeostasis?
a.
 A cell maintains a constant pH.
b.
 A cell maintains a constant glucose concentration.
c.
 A cell maintains a constant salt concentration.
d.
 A cell maintains a constant water concentration.
e.
 All of the above are examples of homeostasis.
 12.
Which of the following descriptions or structures does not match the cell type?
a.
 Sperm cells have flagella.
b.
 Nerve cells have long, thin extensions.
c.
 Epithelial cells are rectangular.
d.
 White blood cells can change shape.
e.
 All of the above are correct.
 13.
Which scientist first viewed living cells?
a.
 Robert Hooke
b.
 Matthias Schleiden
c.
 Theodor Schwann
d.
 Anton van Leeuwenhoek
e.
 August Weismann
 14.
The ratio of the size of the image seen with the microscope to the actual size of the object is:
a.
 magnification.
b.
 resolution.
c.
 resolving power.
d.
 centrifugation.
e.
 None of the above.
 15.
Electron microscopes have a much higher resolution than either the human eye or any light microscope because:
a.
 of their higher magnification.
b.
 the lenses used are of much higher quality.
c.
 of the very short (nanometer) wavelengths of electrons.
d.
 the images are viewed on screens, rather than directly using an eyepiece or ocular lens.
e.
 All of the above.
 16.
The advantage of studying cells using a phase contrast microscope is that:
a.
 the magnification is greater.
b.
 the resolving power is greater.
c.
 it is faster.
d.
 it permits us to view internal structures of live cells.
e.
 it uses a beam of electrons to allow us to see the organelles enclosed by the plasma membrane.
 17.
The accompanying figure is the product of a:

mc017-1.jpg

a.
 phase-contrast light microscope.
b.
 Nomarski differential interference microscope.
c.
 transmission electron microscope.
d.
 scanning electron microscope.
e.
 confocal fluorescence microscope.
 18.
The scanning electron microscope differs from the transmission electron microscope in that the scanning electron microscope:
a.
 can view a live specimen.
b.
 relies on the detection of electrons from the beam after contact with the specimens.
c.
 can view the internal structure of a cell.
d.
 utilizes a beam of light that passes through the specimen.
e.
 gives a three dimensional image of the object being studied.
 19.
Differential centrifugation is a process that:
a.
 separates different components of the cell that function differently.
b.
 separates components of the cell that have a different chemical makeup.
c.
 analyzes the chemical components of the cell.
d.
 separates components of the cell that have different densities.
e.
 allows researchers to view the contents of the cells.
 20.
Which cell structure would not be in a eukaryotic cell, but would be found in a prokaryotic cell?
a.
 cell wall
b.
 flagellum
c.
 ribosomes
d.
 Gogli complex
e.
 DNA
 21.
Membrane-bounded organelles facilitate faster chemical reactions because:
a.
 reactants are within close proximity to each other.
b.
 membranes lower the activation energy of biochemical reactions.
c.
 membrane-bounded organelles act as catalysts for biochemical reactions.
d.
 reactants move faster within membrane-bounded organelles.
e.
 reactants are less likely to encounter each other within membrane-bounded organelles.
 22.
A eukaryotic cell:
a.
 is usually smaller than a prokaryotic cell.
b.
 has its DNA concentrated in one area of the cell without a nuclear membrane.
c.
 typically has a cell wall, in addition to a plasma membrane.
d.
 is a bacteria-like organism.
e.
 has a variety of membranous organelles.
 23.
Membranes facilitate all of the following except:
a.
 facilitating the formation of energy-yielding gradients.
b.
 acting as barriers to ions.
c.
 acting as important “work benches” within cells.
d.
 directing the synthesis of proteins.
e.
 maintaining the identity of different cellular compartments.
 24.
Which of the following structures would not be found in cells of a plant’s roots?
a.
 mitochondria
b.
 chloroplasts
c.
 endoplasmic reticulum
d.
 nucleus
e.
 All of the above would be found in cells of a plant’s root.
 25.
Select the cell type that is not correctly matched with the type of predominate organelle it would need to perform its unique function:
a.
 Sperm cells have many mitochondria to provide energy for the flagellum.
b.
 Pancreas cells have many ribosomes to produce the protein insulin.
c.
 Liver cells have many ribosomes to produce detoxifying protein enzymes.
d.
 Plant leaf cells have many chloroplasts to produce sugar by using energy from sunlight.
e.
 All of the cells above are correctly matched with the predominate type of organelle they would need to perform their unique function.
 26.
Which of the following structures or activities is not directly part of the endomembrane system?
a.
 budding
b.
 lysosomes
c.
 ribosomes
d.
 peroxisomes
e.
 Golgi complex
 27.
DNA is associated with proteins, forming a complex known as:
a.
 chromosomes.
b.
 nucleoli.
c.
 nucleus.
d.
 genes.
e.
 chromatin.
 28.
In the classic experiments by Bracht and Hammerling, the nucleus of Acetabularia was removed, the cap was cut off, a nucleus of a different species was inserted, and the cap was allowed to regenerate. The new cap was then removed. After the second regeneration, the cap was observed, and the following conclusion was made:
a.
 The shape of the cap was controlled by the nucleus, thus, the nucleus was the control center of the cell.
b.
 The shape of the cap was under the control of the stalk, which produced a control substance.
c.
 The shape of the cap was independent of both the stalk and the holdfast.
d.
 The “cren” caps were defective due to some mutation in the cap. Thus, “cren” caps are independent of control from both the base and the holdfast.
e.
 At the time no conclusion could be made because in the early 20th century, biologists did not know about the composition of DNA.
 29.
Nucleoli contain chromosomal regions that specialize in making:
a.
 proteins.
b.
 RNA.
c.
 ribosomes.
d.
 lipids.
e.
 hormones.
 30.
If a toxin, such as a bacterial toxin, destroys ribosomes, what cellular activity will be affected first?
a.
 protein synthesis
b.
 DNA synthesis
c.
 movement
d.
 energy storage
e.
 active transport
 31.
Proteins made on ribosomes may be further modified within the:
a.
 lysosomes.
b.
 nucleus.
c.
 mitochondria.
d.
 Golgi complex.
e.
 peroxisomes.
 32.
The smooth endoplasmic reticulum:
a.
 is absent in most plant cells.
b.
 synthesizes proteins.
c.
 provides structural support.
d.
 synthesizes lipids.
e.
 is required for ribosome synthesis.
Figure 04-02
Use the figure below to answer the corresponding questions.

nar002-1.jpg
 33.
The cellular structure indicated by the arrow in Figure 04-02 is responsible for:
a.
 lipid and fatty acid metabolism.
b.
 protein synthesis.
c.
 digestion of unused organelles.
d.
 replication.
e.
 None of the above.
 34.
Which of the following statements about the structure surrounded by the box in Figure 04-02 is true?
a.
 This structure is only found in plant cells.
b.
 This structure is characteristic of both prokaryotic and eukaryotic cells.
c.
 This structure plays a central role in the process of transcription.
d.
 This structure typically represents a significant portion of the overall cell volume.
e.
 This structure represents the main storage area for the cell.
 35.
Which of the following pairs is correctly matched?
a.
 chloroplast – storage of enzymes
b.
 lysosome – powerhouse of the cell
c.
 nucleolus – site of ribosomal subunit synthesis
d.
 plastids – structural support of the cell
e.
 Golgi complex – production of energy
 36.
Which of the following organelles plays an important role in apoptosis, or programmed cell death?
a.
 ribosomes
b.
 mitochondria
c.
 chloroplasts
d.
 vacuoles
e.
 peroxisomes
 37.
One function of peroxisomes involves the process of:
a.
 cell death.
b.
 water storage.
c.
 protein synthesis.
d.
 DNA replication.
e.
 detoxification.
 38.
During an infection, white blood cells travel to the infected site and phagocytize the pathogens. After phagocytosis, primary lysosomes fuse with the phagocytic vesicle to form a larger vesicle called a secondary lysosome. The reason for this is:
a.
 to introduce antibodies to the phagocytic vesicles.
b.
 to wrap the pathogen in additional membrane, rendering them harmless.
c.
 to coat the bacteria in lipids derived from the Golgi complex, which cover and smother them.
d.
 to mix the pathogens with strong hydrolytic enzymes and destroy them.
e.
 to prepare the bacteria for export from the body.
 39.
All of the following functions are performed by plant vacuoles except:
a.
 maintaining hydrostatic (turgor) pressure.
b.
 waste storage and recycling.
c.
 storage of proteins.
d.
 breakdown of unneeded cellular materials.
e.
 storage of nucleic acids.
 40.
The theory that chloroplasts and mitochondria had their evolutionary beginnings in eukaryotic cells as endosymbionts is supported by all of the following except:
a.
 chloroplasts and mitochondria are completely autonomous within eukaryotic cells.
b.
 chloroplasts and mitochondria have DNA.
c.
 chloroplasts and mitochondria have small ribosomes for protein synthesis.
d.
 chloroplasts and mitochondria are approximately the same size as prokaryotic cells.
e.
 chloroplasts and mitochondria have the same shape as prokaryotic cells.
 41.
A cellular structure found in plant but not animal cells is the:
a.
 chloroplast.
b.
 ribosome.
c.
 endoplasmic reticulum.
d.
 microtubule.
e.
 microfilament.
Figure 04-03
Use the figure below to answer the corresponding questions.

nar003-1.jpg
 42.
Refer to Figure 04-03. The formation of ATP occurs in the portion of the chloroplast labeled:
a.
 structure A.
b.
 structure B.
c.
 structure C.
d.
 structure D.
e.
 structure E.
 43.
The formation of carbohydrates from carbon dioxide and water occurs in the portion of the chloroplast in Figure 04-03 labeled:
a.
 structure A.
b.
 structure B.
c.
 structure C.
d.
 structure D.
e.
 structure E.
 44.
Which of the following is a key component of the cytoskeleton?
a.
 membranes
b.
 cytoskeleton
c.
 DNA
d.
 ribosomes
e.
 None of the above.
 45.
The force necessary to cause microtubules of cilia and flagella to slide alongside one another is provided through the action of _________ proteins, which derive the energy to perform their work directly from ______ molecules.
a.
 kinesin; ADP
b.
 kinesin; glucose
c.
 tubulin; ATP
d.
 dynein; ATP
e.
 dynein; ADP
 46.
The structures in the micrograph could be:

mc046-1.jpg

a.
 chloroplasts.
b.
 cilia.
c.
 RER.
d.
 flagella.
e.
 B and D
Figure 04-04
Use the figure below to answer the corresponding questions.

nar004-1.jpg
 47.
The organelle featured in Figure 04-04:
a.
 is present in a few prokaryotes.
b.
 is the major site of protein synthesis in the cell.
c.
 plays a vital role in packaging materials to be secreted.
d.
 plays a central role in energy metabolism.
e.
 is located in the nucleus.
 48.
The structures indicated by the arrows in Figure 04-04 are:
a.
 thylakoid lamellae.
b.
 grana.
c.
 cristae.
d.
 matrices.
e.
 plastids.
 49.
The main process that occurs at the site of the structures marked by arrows in Figure 04-04 is:
a.
 protein synthesis.
b.
 photosynthesis.
c.
 conversion of food molecules to ATP.
d.
 processing and packaging of proteins.
e.
 transcription.
 50.
A single cell in a smoker’s lung has become cancerous. It doubles its DNA and divides much faster than a normal lung cell. The most likely change that would have caused this condition took place in the:
a.
 nucleus.
b.
 nucleolus.
c.
 microtubule.
d.
 mitochondria.
e.
 lysosome.
 51.
Cells have internal structures called organelles. Which is not a function of organelles?
a.
 Store genetic information.
b.
 Convert energy to more usable forms.
c.
 Synthesize polymers.
d.
 Manufacture membranes.
e.
 All of the above are organelle functions.
 52.
Which of the following is not a cell covering or part of a cell covering?
a.
 glycocalyx
b.
 extracellular matrix
c.
 cristae
d.
 cell wall
e.
 integrins
 53.
The principle cell adhesion molecules in vertebrates and in many invertebrates are cadherins. These are important in:
a.
 preventing the invasiveness of some malignant tumors.
b.
 calcium-dependent adhesion between cells that form multicellular sheets.
c.
 embryonic development.
d.
 cell adhesion in vertebrates and in many invertebrates.
e.
 All of the above.
 54.
All of the following are functions of the cell membrane except:
a.
 transmitting signals.
b.
 participating in energy transfer.
c.
 being freely permeable.
d.
 regulating the passage of materials.
e.
 participating in chemical reactions.
 55.
Which of the following structures is composed of two layers of phospholipids associated with proteins integrated within or attached to these layers?
a.
 cell wall
b.
 plasma membrane
c.
 microfilaments
d.
 flagellum
e.
 ribosomes
 56.
Phospholipids can form bilayer structures because of their:
a.
 rectangular shapes.
b.
 amphipathic nature.
c.
 ability to dissolve well in water.
d.
 inability to associate with other phospholipids.
e.
 lack of fatty acids.
 57.
Phospholipids can form bilayers because the molecules:
a.
 have two distinct regions, one strongly hydrophobic and the other strongly hydrophilic.
b.
 are amphipathic molecules.
c.
 have cylindrical shapes that allow them to associate with water most easily as a bilayer structure.
d.
 Both A and B.
e.
 A, B, and C.
 58.
A key discovery that weakened the Davson-Danielli “sandwich” model of cell membranes was that:
a.
 membrane proteins form a solid sheet on either side of the phospholipid bilayer.
b.
 membrane proteins form a solid sheet separating the phospholipid layer.
c.
 the phospholipids do not associate with each other in the hydrophobic region of membranes.
d.
 membrane proteins were not uniform and did not form flattened sheets.
e.
 membrane proteins occurred in regular organized patterns on the surface of membranes.
 59.
Proposed the fluid mosaic model of cell membrane structure in 1972:
a.
 S. Jonathan Singer.
b.
 Garth Nicolson.
c.
 Hugh Davson.
d.
 Both A and B.
e.
 A, B, and C.
 60.
Which of the following is a typical component of eukaryotic cell membranes?
a.
 DNA
b.
 glucose
c.
 cholesterol
d.
 water
e.
 All of the above.
 61.
Cholesterol within membranes functions as a(an) ____________ through its interactions with both hydrophobic and hydrophilic parts of phospholipids.
a.
 water blocker
b.
 pH buffer
c.
 energy source
d.
 temperature controller
e.
 fluidity buffer
 62.
In a lipid bilayer, ___________ fatty acid tails face each other within the bilayer and form a region that excludes water.
a.
 hypertonic
b.
 hyperosmotic
c.
 hypotonic
d.
 hydrophilic
e.
 hydrophobic
 63.
Which of the following functions best explains the reason for the asymmetrically oriented structure of the proteins in the cell membrane?
a.
 These proteins are manufactured by free ribosomes.
b.
 Each type of protein has its own function.
c.
 These proteins pass through the ER membrane into the ER lumen.
d.
 Enzymes are needed to modify the carbohydrate chains on these proteins.
e.
 These proteins are initially formed by ribosomes on the rough ER.
 64.
Which of the following is not a function associated with membrane proteins?
a.
 Recognition of surface antigens of bacterial cells.
b.
 Forming junctions between adjacent cells.
c.
 Identify the cell as belonging to a particular individual.
d.
 Serve as anchoring points for networks of cytoskeletal elements.
e.
 All of the above are functions associated with membrane proteins.
 65.
Which of the following is not a function of the transmembrane proteins called aquaporins?
a.
 Transmembrane proteins
b.
 Facilitate the rapid transport of water through the plasma membrane
c.
 Located in mammalian kidney tubules
d.
 Respond to specific hormones
e.
 All of the above are functions associated with aquaporins.
 66.
Catalysts are reusable. Enzymes are protein catalysts, and are reusable. Select the protein(s) below that is (are) not used up by the process carried out:
a.
 Sodium-potassium pump carrier proteins
b.
 Aquaporins
c.
 Proteins involved in facilitated diffusion
d.
 Both A and B.
e.
 A, B, and C.
 67.
Integral proteins:
a.
 are weakly bound to the surface of the membrane.
b.
 are strongly bound to the cytosolic surface of the membrane.
c.
 have no hydrophobic portions.
d.
 are completely embedded within the lipid bilayer.
e.
 are amphipathic.
 68.
What is meant by the term “fluid mosaic model”?
a.
 It is the diffusion of lipid-soluble substances through the lipid bilayer.
b.
 It is the movement of lipids and integral proteins within the lipid bilayer.
c.
 It is the solubility of water in the membrane.
d.
 It is the method of substance transport across the membrane.
e.
 It is the movement of surface proteins through the membrane.
 69.
A transmembrane protein differs from other membrane proteins because it:
a.
 is covalently linked to the outer surface of the plasma membrane.
b.
 is a glycoprotein with carbohydrates attached.
c.
 is attached to the inside of the membrane by an ionic bond.
d.
 completely extends through the membrane.
e.
 is completely embedded within the membrane.
 70.
Peripheral proteins are linked to either surface of the plasma membrane by:
a.
 covalent disulfide bonds.
b.
 associating with fatty acids through hydrophobic interactions.
c.
 embedding in one side of the membrane and, thus, not extending through to the other side.
d.
 associating with glycoproteins on the inner membrane surface.
e.
 bonding to integral proteins through weak linkages.
 71.
Which of the following statements explaining the differences in number and types of peripheral proteins found on the inner and outer surfaces of cell membranes is correct?
a.
 The functions of the membrane differ on the inside and outside of the cell.
b.
 Not all proteins can pass through the membrane and, thus, more accumulate on the inside.
c.
 Proteins on the outside of the membrane are synthesized at a slower rate than proteins on the inside of the membrane.
d.
 Proteins on the outside of membrane are made extracellularly and are unable to penetrate the phospholipid bilayer and enter the cell.
e.
 The external peripheral proteins are weakly attached to the membrane and are readily washed away.
 72.
Proteins that are destined to become associated with the inner surface of the plasma membrane are:
a.
 manufactured in the same way as protein hormones.
b.
 manufactured in the same way as proteins destined to become external peripheral proteins.
c.
 made on free ribosomes in the cytoplasm.
d.
 made on ribosomes located on the rough endoplasmic reticulum.
e.
 transported to the plasma membrane within a secretory vesicle.
 73.
Biological membranes are normally permeable to:
a.
 large, hydrophilic molecules.
b.
 small, hydrophilic molecules.
c.
 large, hydrophobic molecules.
d.
 small, hydrophobic molecules.
e.
 None of the above.
 74.
A bottle of perfume is opened on the opposite side of the room and within minutes you begin to smell the perfume. This phenomenon is a classic example of:
a.
 dialysis.
b.
 osmosis.
c.
 active transport.
d.
 facilitated diffusion.
e.
 diffusion.
 75.
Which of the following molecules is least likely to cross a cellular membrane by simple diffusion?
a.
 carbon dioxide
b.
 nitrogen
c.
 oxygen
d.
 potassium ion
e.
 water
 76.
The passive movement of a substance along its concentration gradient is termed:
a.
 active transport.
b.
 dialysis.
c.
 diffusion.
d.
 exocytosis.
e.
 osmosis.
 77.
Simple diffusion may involve the movement of ______________________ through the plasma membrane down a concentration gradient.
a.
 small polar molecules
b.
 small nonpolar molecules
c.
 large polar molecules
d.
 large nonpolar molecules
e.
 water
 78.
The difference between dialysis and osmosis is that:
a.
 in osmosis, the solute moves through a selectively permeable membrane.
b.
 in dialysis, the solvent moves through a selectively permeable membrane.
c.
 in osmosis, the solute moves from a region of high concentration to a region of low concentration.
d.
 in dialysis, the solute moves from a region of high concentration to a region of low concentration.
e.
 in dialysis, the solvent moves from a region of high concentration to a region of low concentration through a selectively permeable membrane.
 79.
If the concentration of solutes in a cell is less than the concentration of solutes in the surrounding fluid, then the extracellular fluid is said to be:
a.
 hypertonic.
b.
 hypotonic.
c.
 isotonic.
d.
 stable.
e.
 amphipathic.
 80.
The higher the concentration of solute in a solution, the _________ the effective water concentration and the ________ the osmotic pressure.
a.
 lower; lower
b.
 lower; higher
c.
 higher; higher
d.
 higher; lower
e.
 Answer cannot be determined from the information provided.
Figure 05-01
Use the figure below to answer the corresponding questions.

nar005-1.jpg
 81.
Which of the following statements about the red blood cells in Figure 05-01 Sample B is true?
a.
 These red blood cells have been placed in an isotonic solution.
b.
 These red blood cells have swollen in response to a hypertonic external solution.
c.
 These red blood cells have swollen in response to a hypotonic external solution.
d.
 These red blood cells have shrunken in response to a hypertonic external solution.
e.
 These red blood cells have shrunken in response to a hypotonic external solution.
 82.
Which of the following statements about the red blood cells in Figure 05-01 Sample A is true?
a.
 There has been no net water movement.
b.
 There has been a net flow of water out of the cell.
c.
 There has been a net flow of water into the cell.
d.
 Pinocytosis has occurred.
e.
 Plasmolysis has occurred.
 83.
A patient who has had a severe hemorrhage accidentally receives a large transfusion of distilled water directly into a major blood vessel. You would expect this mistake to:
a.
 have no unfavorable effect as long as the water is free of bacteria.
b.
 have serious, perhaps fatal consequences because there would be too much fluid to pump.
c.
 have serious, perhaps fatal consequences because the red blood cells could shrink.
d.
 have serious, perhaps fatal consequences because the red blood cells could swell and burst.
e.
 have no serious effect because the kidney could quickly eliminate excess water.
 84.
A plant cell placed in a hypertonic solution will:
a.
 remain unchanged.
b.
 undergo lysis.
c.
 undergo plasmolysis.
d.
 swell slightly.
e.
 become crenated.
 85.
Penicillin is toxic to certain dividing bacterial cells because it prevents cell wall formation, causing the cells to burst. This indicates that the bacteria live in:
a.
 a hypotonic medium.
b.
 a hypertonic medium.
c.
 an isotonic medium.
d.
 a medium with higher osmotic pressure than the cell.
e.
 Both B and D.
 86.
A wilted flower placed in a vase of water for several hours became stiff and stood erect. When it was placed in a salt solution, it wilted. From this information we can say that the cells of the flower are:
a.
 hypotonic to both fresh water and the salt solution.
b.
 hypertonic to both the fresh water and the salt solution.
c.
 hypertonic to fresh water but hypotonic to the salt solution.
d.
 hypotonic to fresh water but hypertonic to the salt solution.
e.
 isotonic to fresh water but hypotonic to the salt solution.
 87.
Which of the following membrane activities does not require the expenditure of energy by the cell?
a.
 active transport
b.
 osmosis
c.
 endocytosis
d.
 exocytosis
e.
 synthesis of more membrane
 88.
Facilitated diffusion:
a.
 requires a transmembrane protein.
b.
 requires ATP.
c.
 can move molecules against a concentration gradient.
d.
 is typically used to transport small nonpolar molecules.
e.
 All of the above.
 89.
A bacterium containing sodium ions at a concentration of 0.1 mM lives in a pond that contains sodium ions at 0.005 mM. Evidently, sodium ions are entering the cell by:
a.
 active transport.
b.
 endocytosis.
c.
 diffusion.
d.
 facilitated diffusion.
e.
 osmosis.
 90.
The energy-requiring movement of materials against a concentration gradient is termed:
a.
 active transport.
b.
 dialysis.
c.
 facilitated diffusion.
d.
 osmosis.
e.
 plasmolysis.
 91.
Although glucose molecules constantly diffuse into a cell along their concentration gradient, equilibrium is never reached and glucose continues to enter the cell. This is a direct result of:
a.
 the very fast turnover rate of glucose metabolism.
b.
 the continuous excretion of glucose from other parts of the cell.
c.
 the rapid and continuous intracellular formation of glucose-6-P.
d.
 the active transport of glucose.
e.
 the ability of the cell to engulf glucose by pinocytosis.
 92.
Which of the following statements about the sodium-potassium pump is true?
a.
 It transports hydrogen ions out of the cell.
b.
 It transports 3 sodium ions out of the cell in exchange for 2 potassium ions.
c.
 It transports 2 sodium ions out of the cell in exchange for 2 potassium ions.
d.
 It transports 2 sodium ions out of the cell in exchange for 3 potassium ions.
e.
 It transports water directly out of the cell.
 93.
A person has a genetic disease that prevents the phospholipids in the plasma membrane of the white blood cells from freely fusing with the other membranes within the cell. How would this disease affect phagocytosis?
a.
 Lysosomes would not be formed.
b.
 Facilitated diffusion would not occur.
c.
 Lysosomes would be formed lacking hydrolytic enzymes.
d.
 The phagocytic vacuole would not fuse with the lysosome.
e.
 Endocytosis would not occur.
 94.
Which of the following are forms of carrier-mediated transport?
a.
 Facilitated diffusion.
b.
 Carrier-mediated active transport.
c.
 Osmosis.
d.
 Both A and B.
e.
 A, B, and C.
 95.
Which of the following describes how facilitated diffusion is powered?
a.
 Facillitated diffusion is “free of cost.”
b.
 Energy is required to do the work of establishing and maintaining a concentration gradient.
c.
 ATP is required directly.
d.
 Both A and B.
e.
 A, B, and C.
 96.
Pinocytosis:
a.
 is engulfment of large particles by the cell.
b.
 occurs in protozoans and algae but not in more complex organisms.
c.
 involves the specific binding of molecules to receptors on the cell surface.
d.
 is the nonspecific uptake of fluids by an invagination of the cell membrane.
e.
 is movement of molecules against the concentration gradient through a permeable membrane.
 97.
Receptor-mediated endocytosis:
a.
 is a passive process.
b.
 involves only membrane transport proteins.
c.
 brings about the selective uptake of materials by enclosing them in membranous vesicles.
d.
 does not require energy.
e.
 is most likely to be found in cells that release large amounts of hormones.
 98.
A human white blood cell engulfs a bacterial cell by:
a.
 carrier-mediated facilitated diffusion.
b.
 exocytosis.
c.
 phagocytosis.
d.
 pinocytosis.
e.
 the sodium-potassium pump.
 99.
Select the receptor mediated endocytosis events that are in the correct (before, after) order:
a.
 Endosome fuses with lysosome; receptors are transported to plasma membrane and recycled.
b.
 Ligand binds to receptors; coated vesicle forms by endocytosis.
c.
 Contents are digested and released in the cytosol; ligand separates from its receptor.
d.
 Endosome fuses with lysosome; receptors are transported to plasma membrane and recycled.
e.
 None of the events are listed in the correct order.
 100.
In cells that are constantly involved in secretion, an equivalent amount of membrane must be returned to the interior of the cell for each vesicle that fuses with the plasma membrane; if this does not occur, then what would happen?
a.
 The ratio of cell surface would decrease, compared to cell volume.
b.
 The cell surface would shrivel.
c.
 The surface area would remain constant.
d.
 The number of membrane receptor proteins would decrease.
e.
 The cell surface will keep expanding.
Figure 05-02
Use the figure below to answer the corresponding questions.

nar006-1.jpg
 101.
The process illustrated in Figure 05-02 is called:
a.
 facilitated diffusion.
b.
 pinocytosis.
c.
 cotransport.
d.
 lysis.
e.
 exocytosis.
 102.
The process illustrated in Figure 05-02 would most likely be used to transport:
a.
 glucose.
b.
 hormones.
c.
 potassium ions.
d.
 carbon dioxide.
e.
 bacteria.
 103.
One difference between tight junctions and desmosomes is that tight junctions:
a.
 are regions where the plasma membrane from two neighboring cells are in actual contact.
b.
 occur only in plants.
c.
 involve connective microfilaments that traverse the space between adjacent cells.
d.
 are anchored by microfilaments on the insides of the cell membranes of adjacent cells.
e.
 contain a 24 nm space between two adjacent membranes.
 104.
Plasmodesmata of plant cells are functionally equivalent to ____________ of animal cells.
a.
 gap junctions
b.
 desmosomes
c.
 tight junctions
d.
 cell surface receptors
e.
 microvilli
 105.
The structures in this figure:

mc105-1.jpg

a.
 provide anchorage points between adjacent cells.
b.
 allow the transport of small molecules and ions between adjacent cells.
c.
 allow passage of materials through intercellular spaces.
d.
 prevent the passage of materials through intercellular spaces.
e.
 can only be found in plants.
 106.
Which of the following is not part of the process of cell signaling?
a.
 Synthesis and release of signaling molecules.
b.
 Facilitated transport.
c.
 Transport to target cells.
d.
 Response by the cell.
e.
 Termination of signaling.
 107.
The process in which cells convert and amplify an extracellular signal into an intracellular signal:
a.
 Synthesis and release of signaling molecules.
b.
 Transport to target cells.
c.
 Signal transduction.
d.
 Response by the cell.
e.
 Termination of signaling.
 108.
In a signaling pathway, the second messenger is often:
a.
 GTP.
b.
 GDP.
c.
 cyclic AMP.
d.
 cyclic ADP.
e.
 ATP.


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Biochemistry PCC

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Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
At what temperature is water most dense?
a.
 0 degrees Celsius
b.
 1 degrees Celsius
c.
 4 degrees Celsius
d.
 10 degrees Celsius
e.
 100 degrees Celsius
 2.
Which property of water enables living things to survive in it?
a.
 high heat of vaporization
b.
 high specific heat
c.
 degree of surface tension
d.
 cohesion
e.
 density of ice
 3.
Which characteristic of water makes the existence of pH possible?
a.
 ionization
b.
 polarity
c.
 adhesion
d.
 cohesion
e.
 None of the above.
 4.
Which of the following types of biologist would need an understanding of chemistry?
a.
 molecular biologist
b.
 ecologist
c.
 evolutionary biologist
d.
 botanist
e.
 All of the above.
 5.
All of the following are inorganic compounds except:
a.
 glucose.
b.
 hydrochloric acid.
c.
 sodium chloride.
d.
 sodium hydroxide.
e.
 water.
 6.
An element is defined as a substance that:
a.
 is composed of more than one kind of atom.
b.
 is held together by covalent bonds.
c.
 cannot be broken into simpler substances by chemical reactions.
d.
 cannot burn.
e.
 is soluble in both acid and water.
 7.
Which of the following determines the type of element?
a.
 the number of electrons
b.
 the number of protons
c.
 the number of neutrons
d.
 the number of valence electrons
e.
 the number of energy levels
 8.
Which of the following elements is not responsible for a significant portion of the mass of living organisms?
a.
 O
b.
 S
c.
 N
d.
 H
e.
 C
 9.
An element found in minute quantities in living organisms is called:
a.
 a heavy element.
b.
 a vitamin.
c.
 an organic compound.
d.
 an isotope.
e.
 a trace element.
 10.
Select the incorrectly matched pair:
a.
 The 1st principal energy level contains 1 orbital.
b.
 The 2nd principal energy level contains 4 orbitals.
c.
 The 1st principal energy level contains a maximum of 2 electrons.
d.
 The 2nd energy level contains a maximum of 10 electrons.
e.
 All of the above are correctly matched.
 11.
Chlorine has seven electrons in its valence shell. The number of electrons it must gain to complete its valence shell is:
a.
 one.
b.
 two.
c.
 three.
d.
 seven.
e.
 eight.
 12.
An atom has six protons and eight neutrons. Its atomic mass is ____________ atomic mass units.
a.
 two
b.
 four
c.
 six
d.
 eight
e.
 fourteen
 13.
This determines the chemical properties of an element:
a.
 the atomic number.
b.
 the atomic weight.
c.
 the number of energy levels.
d.
 the number of valence electrons.
e.
 orbitals.
 14.
The difference between an electrically neutral atom and an ion is that:
a.
 an ion has an unequal number of protons and electrons, while an atom has an equal number.
b.
 an ion has an equal number of protons and electrons, while an atom has an unequal number.
c.
 an atom has an unequal number of neutrons and protons, while an ion has an equal number.
d.
 an atom has its electrons in orbitals, while an ion has its electrons in its nucleus.
e.
 an atom must have an equal number of neutrons and electrons, while an ion does not.
 15.
The difference between a stable isotope and a radioisotope is that:
a.
 the stable isotope emits radiation.
b.
 the radioisotope emits radiation.
c.
 the stable isotope emits light.
d.
 the stable isotope absorbs radiation.
e.
 the radioisotope has an unequal number of protons and electrons.
Figure 02-01
Use the figure below to answer the corresponding questions.nar001-1.jpg
 16.
Figure 02-01 represents:
a.
 two isotopes of the same element.
b.
 two different elements.
c.
 two different ions.
d.
 an acid and a base.
e.
 a cation and an anion.
 17.
The atomic mass of the atom identified as A in Figure 02-01 is:
a.
 2.
b.
 6.
c.
 8.
d.
 12.
e.
 18.
 18.
The difference between the two atoms in Figure 02-01 is:
a.
 pH.
b.
 the number of electrons.
c.
 the number of protons.
d.
 the number of neutrons.
e.
 electric charge.
 19.
Radioisotopes are used in all of the following scientific applications except:
a.
 dating fossils.
b.
 determining the sequence of genetic information in DNA.
c.
 localization of a drug, such as marijuana.
d.
 the treatment of cancer.
e.
 monitoring changes in the salinity of an estuary.
 20.
Isotopes differ from each other with respect to the number of:
a.
 protons.
b.
 electrons.
c.
 neutrons.
d.
 protons and electrons.
e.
 neutrons and protons.
 21.
When a chemical reaction is at equilibrium:
a.
 the forward reaction is going faster.
b.
 the reverse reaction is going faster.
c.
 the forward and reverse reactions are proceeding at equal rates.
d.
 the forward reaction stops.
e.
 the reverse reaction stops.
 22.
Any chemical interaction between atoms:
a.
 involves neutrons.
b.
 may potentially involve any electron.
c.
 involves protons.
d.
 involves only valence electrons.
e.
 involves only the nuclear subatomic particles.
 23.
The molecular mass of C6H12O6 is 180 amu. 0.25 moles of this substance contain:
a.
 180 daltons.
b.
 45 g.
c.
 1.8 g.
d.
 45 daltons.
e.
 180 g.
 24.
How many molecules are present in one mole of C6H12O6?
a.
 1.7 ´ 10-10 molecules
b.
 1.3 ´ 1010 molecules
c.
 5 molecules
d.
 1.7 ´ 1022 molecules
e.
 6.02 ´ 1023 molecules
Figure 02-02
Use the figure below to answer the corresponding questions.nar002-1.jpg
 25.
Figure 02-02 represents:
a.
 elemental helium.
b.
 molecular hydrogen.
c.
 molecular helium.
d.
 a water molecule.
e.
 molecular oxygen.
 26.
The type of bond illustrated in Figure 02-02 is:
a.
 an ionic bond.
b.
 a polar bond.
c.
 a single covalent bond.
d.
 a hydrogen bond.
e.
 a double covalent bond.
 27.
Select the covalent bond that involves 2 electrons:
a.
 single
b.
 double
c.
 triple
d.
 Both A and B.
e.
 Both A and C.
 28.
The representation H – O – H is known as:
a.
 a structural formula.
b.
 a simplest formula.
c.
 a molecular formula.
d.
 a Lewis structure.
e.
 an orbital diagram.
 29.
Which of the following choices correctly identifies a reactant in the following chemical equation? CO2 + H2O « H2CO3
a.
 carbonic acid
b.
 oxygen
c.
 water
d.
 sugar
e.
 carbon monoxide
 30.
In a chemical reaction, the product is:
a.
 generally written on the right side of the equation.
b.
 always in equilibrium with the reactants.
c.
 the substance that is generated by the reaction.
d.
 only joined by an ionic bond.
e.
 Both A and C.
 31.
A covalent bond:
a.
 can form only between identical atoms.
b.
 involves a sharing of only one pair of electrons.
c.
 is always polar.
d.
 may be polar or nonpolar depending on the atoms involved.
e.
 always forms between identical molecules.
 32.
In a water molecule, because oxygen is more electronegative than hydrogen, the shared electrons are more commonly found around the ____________ nucleus than the ____________ nucleus.
a.
 oxygen; hydrogen
b.
 hydrogen; oxygen
c.
 hydrogen; other hydrogen
d.
 oxygen; nitrogen
e.
 nitrogen; oxygen
 33.
The covalent bond between a hydrogen atom and the oxygen atom in water is formed when:
a.
 hydrogen gains an electron from oxygen.
b.
 hydrogen and oxygen share an electron pair.
c.
 hydrogen and oxygen both lose electrons from their outer shells.
d.
 hydrogen and oxygen both gain electrons in their outer shells.
e.
 hydrogen gains an electron from oxygen.
 34.
Covalently bonded atoms with similar electronic negativities are:
a.
 ionic.
b.
 polar.
c.
 nonpolar.
d.
 partially positive.
e.
 partially negative.
 35.
An atom becomes a cation if:
a.
 it gains one or more electron.
b.
 it loses one or more electron.
c.
 it shares electrons.
d.
 one or more of its electrons changes energy levels.
e.
 it emits radiation.
 36.
In the formation of common table salt, sodium and chlorine interact because:
a.
 sodium and chlorine share a pair of electrons.
b.
 sodium and chlorine share two pairs of electrons.
c.
 chlorine donates seven electrons to sodium.
d.
 there is no electron exchange.
e.
 sodium donates one electron to chlorine.
 37.
Table salt dissolves easily in water because:
a.
 water can form covalent linkages with salt molecules.
b.
 water can remove electrons from the chloride ion, which causes the latter to dissociate from the sodium and dissolve.
c.
 water can add electrons to the sodium ion.
d.
 water is polar and salt is nonpolar. Nonpolar compounds are more soluble in polar solvents because they are able to form strong covalent bonds that result in a breaking up of the molecule being dissolved.
e.
 the partial positive charge of the hydrogens in the water molecule can associate with the negative charge of the chloride ion, and the partial negative charge of the oxygen of the water molecule can associate with the positive charge of the sodium atom.
 38.
Which one of the following atoms would most likely be involved in an ionic bond?
a.
 hydrogen
b.
 oxygen
c.
 sodium
d.
 Both A and B.
e.
 Both A and C.
 39.
The process whereby water molecules surround ions during the process of dissolving is called:
a.
 reduction.
b.
 hydration.
c.
 buffering.
d.
 oxidation.
e.
 vaporization.
 40.
Which component becomes oxidized in the following chemical reaction?
4 Fe + 3 O2 ® 2 Fe2O3
a.
 water
b.
 iron
c.
 oxygen
d.
 rust
e.
 hydrogen
 41.
Which component is the oxidizing agent in the following chemical reaction?
4 Fe + 3 O2 ® 2 Fe2O3
a.
 water
b.
 iron
c.
 oxygen
d.
 rust
e.
 hydrogen
 42.
Which of the following statements is not correct?
a.
 Water heats up and cools down very quickly.
b.
 The amount of heat required to raise the temperature of 1 g of water 1 °C is one calorie.
c.
 Due to hydrogen bonds, water has a high surface tension.
d.
 Large bodies of water have relatively constant temperatures.
e.
 When one gram of water evaporates, it removes heat.
 43.
It takes one calorie of heat to raise the temperature of one gram of water one degree Celsius at sea level. This is referred to as the _______________________ of water.
a.
 heat of fusion
b.
 heat of vaporization
c.
 specific heat
d.
 heat of transformation
e.
 heat of homeostasis
 44.

Which characteristic of water molecules directly contributes to the remarkable “water walking” success of the aquatic insects pictured in the accompanying figure?

mc044-1.jpg

a.
 hydrogen bonds
b.
 capillary action
c.
 nonpolar covalent bonds
d.
 ionic bonds
e.
 adhesive forces
 45.
The cohesiveness between water molecules is due largely to:
a.
 hydrogen bonds.
b.
 polar covalent bonds.
c.
 nonpolar covalent bonds.
d.
 ionic bonds.
e.
 hydrophobic interactions.
 46.
A stalk of celery is placed in a solution of blue colored dye. After one hour, the leaves have blue fluid in their veins. Which property of water is being demonstrated?
a.
 adhesion and cohesion
b.
 evaporation and cooling
c.
 lower density as a solid than as a liquid
d.
 high specific heat
e.
 surface tension
 47.
Evaporative cooling is a process whereby ____________ moving ____________ molecules vaporize, thus ____________ large amounts of heat.
a.
 slow; water; adding
b.
 fast; water; removing
c.
 slow; oxygen; adding
d.
 fast; oxygen; removing
e.
 fast; carbon dioxide; removing
 48.
In a mixture, which one would be present in the least amount?
a.
 solvent
b.
 solute
c.
 water
d.
 Both A and B.
e.
 Both A and C.
 49.
This characteristic of a molecule determines the ability of hydrogen bonds to form between it and hydrogen:
a.
 A non polar atom
b.
 An atom with a partial positive charge
c.
 An atom with a partial negative charge
d.
 None of the above.
e.
 All of the above.
 50.
A pH of 4 is ____________ times more ____________ than a pH of 7.
a.
 3; basic
b.
 3; acidic
c.
 1000; neutral
d.
 1000; basic
e.
 1000; acidic
 51.
What is the OH- concentration of a solution having a pH of 2?
a.
 1 ´ 10-12
b.
 1 ´ 10-10
c.
 1 ´ 10-7
d.
 1 ´ 10-2
e.
 1 ´ 10-1
 52.
When a small amount of hydrochloric acid (HCl) is added to a solution of Na2HPO4, the pH of the solution does not change markedly. The pH also does not change drastically when a small amount of sodium hydroxide (NaOH) is added to this same solution. Based on these observations, the compound Na2HPO4 is:
a.
 able to donate hydrogen atoms to HCl.
b.
 able to remove hydrogen ions from the OH- of NaOH.
c.
 acting as a buffer.
d.
 an enzyme facilitating the reaction between HCl and NaOH.
e.
 All of the above.
 53.
A salt is a compound in which the hydrogen ion of _________________ is replaced by some other cation.
a.
 a base
b.
 an acid
c.
 an anion
d.
 a hydroxide ion
e.
 water
 54.
Which concentration(s) results in a pH of 7?
a.
 higher concentrations of hydrogen ions than hydroxide ions
b.
 higher concentrations of hydroxide ions than hydrogen ions
c.
 equal concentrations of hydroxide ions than hydrogen ions
d.
 Both A and B.
e.
 None of the above.
 55.
Identify the chemical(s) that act(s) as a buffer in human blood:
a.
 bicarbonate
b.
 hydrogen ions
c.
 carbon dioxide
d.
 water
e.
 None of the above.
 56.
Identify the hydrogen ion concentration that represents the lowest pH from the following list:
a.
 1 ´ 10-3
b.
 1 ´ 10-4
c.
 1 ´ 10-7
d.
 1 ´ 10-11
e.
 1 ´ 10-14
 57.
Which of the following has a pH closest to that of human blood?
a.
 beer
b.
 coffee
c.
 rain water
d.
 sea water
e.
 oven cleaner
 58.
Which of the following would most likely form electrolytes in water?
a.
 glucose
b.
 ethanol
c.
 An organic compound
d.
 An inorganic compound
e.
 None of the above.
 59.
Which of the following is not a property of carbon?
a.
 Carbon-to-carbon bonds are limited to single bonds.
b.
 Carbon has four valence electrons.
c.
 Carbon can form bonds to various other atoms.
d.
 Two carbon atoms can share three electron pairs with each other.
e.
 Carbon-to-carbon bonds are strong.
 60.
What aspect of long carbon chains makes them ideal for forming the backbones of long biomolecules?
a.
 The carbon atom itself is strong and hard to split.
b.
 Carbon can form a maximum of five covalent bonds with other atoms.
c.
 Carbons can form a maximum of three covalent bonds with other atoms.
d.
 Carbon-to-carbon covalent bonds are strong.
e.
 Carbon-to-carbon hydrogen bonds are weak and transitory.
 61.
The highly polarized nature of compounds containing carboxyl groups can be attributed to:
a.
 the presence of two highly electronegative carbon atoms.
b.
 the presence of two highly electropositive carbon atoms.
c.
 the presence of two highly electronegative oxygen atoms.
d.
 the presence of two highly electropositive oxygen atoms.
e.
 None of the above.
 62.

The number of electron pairs shared between carbon 2 and 3 in the accompanying figure is:

mc062-1.jpg

a.
 one.
b.
 one and a half.
c.
 two.
d.
 three.
e.
 None of the above.
 63.

The two molecules in the following figure represent:

mc063-1.jpg

a.
 ionized structures.
b.
 enantiomers.
c.
 secondary structures.
d.
 geometric isomers.
e.
 polymers.
 64.
This functional group is weakly basic because it can accept an H+ ion:
a.
 hydroxyl
b.
 carbonyl
c.
 amino
d.
 phosphate
e.
 sulfhydryl
 65.
This functional group forms cross bridges that help stabilize protein tertiary structure:
a.
 hydroxyl
b.
 carbonyl
c.
 amino
d.
 phosphate
e.
 sulfhydryl
 66.
The chemical interactions of large hydrocarbons are largely determined by:
a.
 their solubility in water.
b.
 their functional groups.
c.
 their polar nature.
d.
 isomerization of these hydrocarbons into other forms.
e.
 the hydrogens bonded to the carbon atoms.
 67.
Hydrocarbons are hydrophobic because:
a.
 the covalent bonds between hydrogen and carbon are nonpolar.
b.
 they contain functional groups.
c.
 they exist as isomers.
d.
 Both A and B.
e.
 Both A and C.
 68.
Which pair is mismatched?
a.
 monsaccharide:maltose
b.
 disaccharide:sucrose
c.
 polysaccharide:cellulose
d.
 None of these pairs are correctly matched.
e.
 All of these pairs are correctly matched.
 69.
Which of these terms is most inclusive?
a.
 monosaccharide
b.
 starch
c.
 polysaccharide
d.
 disaccharide
e.
 carbohydrate
 70.
Glucose dissolves in water because:
a.
 it ionizes.
b.
 it is a polysaccharide.
c.
 it has polar hydroxyl groups that interact with polar water molecules.
d.
 it has a very reactive primary structure.
e.
 it is hydrophobic.
 71.
Carbohydrate molecules:
a.
 serve as structural components of human cell walls.
b.
 form the regulatory compounds known as enzymes.
c.
 are a source of energy.
d.
 help protect vital organs from damage.
e.
 contain the genetic information of a cell.
 72.
A chemical reaction in which organic compounds are synthesized from their building blocks is called:
a.
 hydrolysis.
b.
 condensation.
c.
 oxidation.
d.
 reduction.
e.
 dissociation.
Figure 03-01
Use the figure below to answer the corresponding questions.nar003-1.jpg
 73.
The process illustrated in Figure 03-01 is called:
a.
 condensation.
b.
 protein synthesis.
c.
 hydrolysis.
d.
 dehydration synthesis.
e.
 denaturation.
 74.
The products of the process in Figure 03-01 are:
a.
 amino acids.
b.
 molecules of glycerol.
c.
 representative of a glycoside linkage.
d.
 enzymes.
e.
 monosaccharides.
 75.
Which one of the following carbohydrates is the most structurally complex?
a.
 sucrose
b.
 fructose
c.
 cellulose
d.
 glucose
e.
 a disaccharide
 76.
In which of the following reactions must the equivalent of a water molecule be added in order to break a bond?
a.
 fatty acids + glycerol ® fat
b.
 glucose + fructose ® sucrose
c.
 glycogen ® glucose
d.
 alanine + glycine ® dipeptide
e.
 glucose ® cellulose
 77.
Which of the following illustrates hydrolysis?
a.
 the reaction of two monosaccharides to form a disaccharide
b.
 the reaction of two amino acids to form a dipeptide
c.
 the reaction of a hydrogen atom and a hydroxide ion to form water
d.
 the reaction of a fat to form glycerol and fatty acids
e.
 the formation of ATP from ADP and inorganic phosphate
 78.
The difference between a hexose and a pentose is that:
a.
 a hexose is saturated, and a pentose is undersaturated.
b.
 a hexose is hydrophilic, and a pentose is hydrophobic.
c.
 a hexose always has six hydroxyl groups, and a pentose always has five.
d.
 a hexose always has six carbons, but a pentose always has five carbons.
e.
 a hexose can be polymerized, but a pentose cannot.
 79.
Monosaccharides are water soluble because:
a.
 they contain a large number of methyl groups.
b.
 they have a large number of polar hydroxyl groups.
c.
 they have at least one double bond between adjacent carbons.
d.
 they have large numbers of nonpolar carbons in their backbones.
e.
 they can form ring structures.
 80.
A carbohydrate energy storage molecule found in animal liver and muscle cells is:
a.
 starch.
b.
 glycogen.
c.
 cellulose.
d.
 fatty acids.
e.
 cholesterol.
 81.
Amyloplasts are organelles that store:
a.
 fat.
b.
 starch.
c.
 protein.
d.
 lipids.
e.
 DNA.
 82.
The major function(s) of lipids includes:
a.
 storing energy.
b.
 serving as structural components of cellular membranes.
c.
 serving as hormones.
d.
 Both A and B.
e.
 A, B, and C are correct.
 83.
The hydrolysis of triacylglycerol will yield:
a.
 three fatty acids and one glycerol.
b.
 three glycerols and one fatty acid.
c.
 two fatty acids and three glycerols.
d.
 one fatty acid, one amino acid, and one glucose.
e.
 one fatty acid, one phosphate, and one glycerol.
 84.
A molecule of a saturated triacylglycerol contains:
a.
 the maximum number of double bonds between carbons in the fatty acid chains.
b.
 the maximum number of triple bonds between carbons in the fatty acid chains.
c.
 the maximum number of hydrogen atoms in the fatty acid chains.
d.
 fatty acid chains with both amino and carboxyl groups.
e.
 alternating single and double bonds between carbons in the fatty acid chains.
 85.
Which of the following statements concerning unsaturated fats is correct?
a.
 They are more common in animals.
b.
 They have no double bonds in the carbon chains of their fatty acids.
c.
 They are generally liquids at room temperature.
d.
 They contain more hydrogen than do saturated fats having the same number of carbon atoms.
e.
 They have fewer fatty acids per fat molecule than do saturated fats.
 86.
The major difference between a structural lipid, such as those in cell membranes, and a storage fat is the fact that the structural lipid:
a.
 most commonly contains phosphate.
b.
 does not contain glycerol.
c.
 has four fatty acids attached to glucose.
d.
 is entirely hydrophobic.
e.
 is nonpolar.
 87.
An amphipathic molecule has:
a.
 two polar ends.
b.
 two hydrophobic ends.
c.
 a hydrophobic and a hydrophilic portion.
d.
 only one hydrophobic end.
e.
 only one hydrophilic end.
 88.

The most abundant molecules in this structure are:

mc088-1.jpg

a.
 structural proteins.
b.
 polysaccharides.
c.
 triacylglycerols.
d.
 phospholipids.
e.
 polypeptides.
 89.
Which of the following molecules is not grouped with the lipids?
a.
 prostaglandins
b.
 steroids
c.
 cholesterol
d.
 carotenoids
e.
 None of the above, all are lipids.
 90.
The hydrogenation process used to make margarine from cooking oil produces fatty acids that:
a.
 are known to increase the risk of cardiovascular disease.
b.
 contain fewer double bonds.
c.
 can contain rearrange double bonds to the cis configuration.
d.
 Both A and B are correct.
e.
 A, B, and C are correct.
 91.
Which statement is false?
a.
 Trans fatty acids are unsaturated.
b.
 Trans fatty acids are more solid at room temperature than cis fatty acids.
c.
 Unsaturated fatty acids are liquid at room temperature.
d.
 Saturated fatty acids are solid at room temperature.
e.
 All of these statements are true.
 92.
The major function(s) of proteins includes:
a.
 catalyzing chemical reactions.
b.
 controlling the expression of genes.
c.
 strengthening and protecting cells and tissues.
d.
 Both A and B.
e.
 A, B, and C are correct.
 93.
There are 20 different amino acids in the proteins that make up the tissues of living organisms. The primary difference between these amino acids is in their:
a.
 R or variable groups.
b.
 number of potassium groups.
c.
 number of phosphate groups.
d.
 number of carbonyl groups.
e.
 number of asymmetric carbons.
Figure 03-02
Use the figure below to answer the corresponding questions.nar004-1.jpg
 94.
In Figure 03-02, ionic attractions would form between the R groups of which amino acids?
a.
 1 and 3
b.
 2 and 4
c.
 3 and 5
d.
 4 and 6
e.
 None of the above.
 95.
Hydrophobic interactions would occur between the R groups of which two amino acids in Figure 03-02?
a.
 1 and 4
b.
 2 and 5
c.
 3 and 6
d.
 2 and 4
e.
 3 and 5
 96.
Which of the following is responsible for the alpha-helical structure of proteins?
a.
 hydrophobic interactions
b.
 nonpolar covalent bonds
c.
 ionic interactions
d.
 hydrogen bonds
e.
 polar covalent bonds
 97.
At which level of protein structure are peptide bonds most important?
a.
 primary
b.
 secondary
c.
 tertiary
d.
 quaternary
e.
 globular
 98.
Proteins with alpha helical forms exhibit this property:
a.
 strength
b.
 elasticity
c.
 heat stability
d.
 rigidity
e.
 All of the above.
 99.
Which of the following would help stabilize a protein the most?
a.
 alpha helix
b.
 beta pleated sheet
c.
 hydrogen bonds
d.
 hydrophobic interactions
e.
 disulfide bonds
 100.
Some proteins are important biological buffers because:
a.
 they react with water to produce carbon dioxide, which neutralizes acids.
b.
 they contain weakly acidic and weakly basic groups.
c.
 they are able to absorb great amounts of carbon dioxide during condensation reactions.
d.
 they produce carbonic acid upon hydrolysis.
e.
 All of the above.
 101.
The tertiary structure of proteins is typified by the:
a.
 association of several polypeptide chains by weak bonds.
b.
 order in which amino acids are joined in a peptide chain.
c.
 bonding of two amino acids to form a dipeptide.
d.
 folding of a peptide chain to form an alpha helix.
e.
 three-dimensional shape of an individual polypeptide chain.
 102.

All of the following types of chemical bonds are responsible for maintaining the tertiary structure of this polypeptide except:

mc102-1.jpg

a.
 ionic bonds.
b.
 hydrogen bonds.
c.
 hydrophobic interactions.
d.
 disulfide bonds.
e.
 peptide bonds.
 103.
Regulatory proteins:
a.
 defend against foreign invaders.
b.
 store nutrients.
c.
 catalyze a specific chemical reaction.
d.
 control the expression of specific genes.
e.
 strengthen and protect cells and tissues.
 104.
Molecular chaperones are proteins that mediate the folding process of:
a.
 other proteins.
b.
 amino acids.
c.
 lipids.
d.
 DNA.
e.
 sugars.
 105.

The following amino acid would be characterized as __________ based on the chemical properties of its side chain.

mc105-1.jpg

a.
 nonpolar
b.
 acidic
c.
 basic
d.
 hydrophilic
e.
 electrically charged
 106.
Which of the following statements is true of proteins?
a.
 Proteins lose some or all of their normal activity if their three-dimensional structure is disrupted.
b.
 Proteins are composed of ribose, phosphate, and a nitrogen-containing base.
c.
 The activity of proteins is independent of temperature and pH.
d.
 Denaturation is usually reversible.
e.
 All proteins are enzymes.
 107.

If the differently shaded portions of this molecule represent different polypeptide chains, then this figure is representative of:

mc107-1.jpg

a.
 an amino acid.
b.
 the quaternary structure of a protein.
c.
 a steroid hormone.
d.
 cellulose.
e.
 a carotenoid.
 108.
Which of the following statements is false?
a.
 DNA is usually composed of two nucleotide strands.
b.
 DNA contains deoxyribose.
c.
 DNA does not normally contain uracil.
d.
 The nucleotides of DNA are linked by phosphodiester linkages.
e.
 DNA does not normally contain a phosphate group.
 109.
ATP is important in living organisms because:
a.
 like all other nucleic acids, it stores hereditary information.
b.
 like RNA, it acts as a source code for the formation of proteins.
c.
 it can transfer some of its energy to other chemicals.
d.
 it is an important structural component of cell membranes.
e.
 it is easily converted to starch for long-term storage.
 110.
Which of the following statements best summarizes the differences between RNA and DNA?
a.
 RNA is a protein and DNA is a nucleic acid.
b.
 DNA is a polymer and RNA is a monomer.
c.
 DNA comprises the genes, while RNA is a direct participant in the process of protein synthesis.
d.
 RNA is a single-stranded form of DNA.
e.
 DNA is the primary energy currency of all cells.
 111.
Analysis of a certain complex compound shows that it contains phosphate groups, ribose groups, and pyrimidines. Based on this information, which of the following is the best description of this compound?
a.
 It is most likely ribonucleic acid.
b.
 It is DNA.
c.
 It is an inorganic compound.
d.
 It contains thymine.
e.
 It is a polypeptide.
 112.
Which of the following are most directly arranged from DNA structure?
a.
 polysaccharides
b.
 polypeptides
c.
 nucleotides
d.
 triglycerides
e.
 fatty acids
 113.
This molecule transmits heredity information:
a.
 cholesterol
b.
 adenosine triphosphate
c.
 nucleic acid
d.
 fatty acid
e.
 polysaccharide
Figure 03-03
Use the figure to answer the corresponding questions.
nar005-1.jpg
 114.
The molecular fragment represented in Figure 03-03 is:
a.
 ATP.
b.
 RNA.
c.
 a protein.
d.
 a nucleotide.
e.
 a polysaccharide.
 115.
The type of connection between the atoms at the point labeled 1 in Figure 03-03 is:
a.
 a peptide bond.
b.
 a glycoside linkage.
c.
 a disulfide bond.
d.
 a phosphodiester linkage.
e.
 a hydrogen bond.
 116.

Which portion of the following molecule is easily transferred and therefore responsible for the energy transfer property of this molecule?

mc116-1.jpg

a.
 1
b.
 2
c.
 3
d.
 1 and 2
e.
 None of the above.
 117.
Ester linkages would not be formed during condensation reactions that produce:
a.
 polysaccahrides.
b.
 triacylglycerols.
c.
 polypeptides.
d.
 nucleic acids.
e.
 All of the above contain ester linkages that are formed during condensation reactions.
 118.
Which monomer is incorrectly matched with the corresponding polymer?
a.
 Amino acids are used to build proteins.
b.
 Monosaccharides are used to build polysaccharides.
c.
 Fatty acids are used to build nucleic acids.
d.
 Glucose molecules are used to build starches.
e.
 All of these monomers are correctly matched with the corresponding polymer.

 
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