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Unit 1A Chapters 1-3 Biochemistry

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
Which of the following properties or processes do we associate with living things?
a.
evolutionary adaptations
b.
energy processing
c.
responding to the environment
d.
growth and reproduction
e.
all of the above
 

 2. 
Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level?
a.
organelle, tissue, biosphere, ecosystem, population, organism
b.
cell, community, population, organ system, molecule, organelle
c.
organism, community, biosphere, molecule, tissue, organ
d.
ecosystem, cell, population, tissue, organism, organ system
e.
molecule, cell, organ system, population, ecosystem, biosphere
 

 3. 
What is a localized group of organisms that belong to the same species?
a.
biosystem
b.
community
c.
population
d.
ecosystem
e.
organ system
 

 4. 
A maple leaf is at which level in the hierarchy of biological organization?
a.
tissue
b.
cell
c.
organelle
d.
organ
e.
organ system
 

 5. 
Which of these is an example of an organelle?
a.
chloroplast
b.
muscle
c.
epidermis
d.
intestine
e.
maple leaf
 

 6. 
In terms of the hierarchical organization of life, a bacterium is at the ____ level of organization, whereas a human is at the ____ level of organization.
a.
single-celled organism; multicellular organism
b.
single organelle; organism
c.
organelle; organ system
d.
single tissue; multicellular organism
e.
tissue; organism
 

 7. 
As a result of photosynthesis, plants release ____ into the atmosphere.
a.
methane
b.
carbon dioxide
c.
water
d.
minerals
e.
oxygen
 

 8. 
Which of the following is the main source of energy for producers such as plants and other photosynthetic organisms?
a.
sunlight or solar energy
b.
carbon dioxide or kinetic energy
c.
heat or thermal energy
d.
chemicals or chemical energy
e.
both B and D
 

 9. 
For most ecosystems ____ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of ____.
a.
sunlight; heat
b.
heat; light
c.
plants; animals
d.
plants; heat
e.
producers; consumers
 

 10. 
The lowest level of biological organization that can perform all the activities required for life is the
a.
organelle-for example, a chloroplast.
b.
cell-for example, a skin cell.
c.
tissue-for example, nervous tissue.
d.
organ system-for example, the reproductive system.
e.
organism-for example, an amoeba, dog, human, or maple tree.
 

 11. 
Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material?
a.
animal
b.
plant
c.
archaea
d.
A and B only
e.
A, B, and C
 

 12. 
The chemical reactions within cells are regulated by organic catalysts called
a.
feedback activators.
b.
feedback inhibitors.
c.
enzymes.
d.
metabolites.
e.
nutrients.
 

 13. 
Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of
a.
a bioinformatic system.
b.
positive feedback.
c.
negative feedback.
d.
feedback inhibition.
e.
both C and D
 

 14. 
When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of
a.
catalytic feedback.
b.
positive feedback.
c.
negative feedback.
d.
bioinformatic regulation.
e.
both A and B
 

 15. 
Prokaryotic and eukaryotic cells generally have which of the following features in common?
a.
a membrane-bounded nucleus
b.
a cell wall made of cellulose
c.
ribosomes
d.
flagella or cilia that contain microtubules
e.
linear chromosomes made of DNA and protein
 

 16. 
Which of the following are characteristics shared by members of both domain Bacteria and domain Archaea?
a.
cytosol
b.
nucleus
c.
DNA
d.
A and C only
e.
A, B, and C
 

 17. 
All eukaryotes belong to which group(s)?
a.
domain Bacteria
b.
domain Archaea
c.
domain Eukarya
d.
kingdom Protista
e.
both C and D
 

 18. 
Species that are in the same ____ are more closely related than species that are only in the same ____.
a.
phylum; class
b.
family; order
c.
class; order
d.
family; genus
e.
kingdom; phylum
 

 19. 
Which of these is reflective of the hierarchical organization of life from most to least inclusive?
a.
kingdom, order, family, phylum, class, genus, species
b.
phylum, class, order, kingdom, family, genus, species
c.
kingdom, phylum, class, order, family, genus, species
d.
genus, species, kingdom, phylum, class, order, family
e.
class, order, kingdom, phylum, family, genus, species
 

 20. 
Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates?
a.
nitrogen
b.
calcium
c.
iodine
d.
sodium
e.
phosphorus
 

 21. 
Which of the following statements is false?
a.
Atoms of the various elements differ in their number of subatomic particles.
b.
All atoms of a particular element have the same number of protons in their nuclei.
c.
The neutrons and protons present in the nucleus of an atom are almost identical in mass; each has a mass of about 1 dalton.
d.
An atom is the smallest unit of an element that still retains the properties of the element.
e.
Protons and electrons are electrically charged particles. Protons have one unit of negative charge, and electrons have one unit of positive charge.
 

 22. 
Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus?
a.
atomic mass
b.
atomic weight
c.
atomic number
d.
mass weight
e.
mass number
 

 23. 
Oxygen has an atomic number of 8 and a mass number of 16. Thus, the atomic mass of an oxygen atom is
a.
exactly 8 grams.
b.
exactly 8 daltons.
c.
approximately 16 grams.
d.
approximately 16 daltons.
e.
24 amu (atomic mass units).
 

 24. 
Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have
a.
20 protons.
b.
40 electrons.
c.
40 neutrons.
d.
A and B only
e.
A, B, and C
 

 25. 
One difference between carbon-12 mc025-1.jpg and carbon-14 mc025-2.jpg is that carbon-14 has
a.
two more protons than carbon-12.
b.
two more electrons than carbon-12.
c.
two more neutrons than carbon-12.
d.
A and C only
e.
B and C only
 

 26. 
Two isotopes of the same element will have different numbers of
a.
protons.
b.
neutrons.
c.
electrons.
d.
protons and neutrons.
e.
neutrons and electrons.
 

 27. 
Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that
a.
an electron may move to an electron shell farther out from the nucleus.
b.
an electron may move to an electron shell closer to the nucleus.
c.
the atom may become a radioactive isotope.
d.
the atom would become a positively charged ion, or cation.
e.
the atom would become a negatively charged ion, or anion.
 
 
Use the figure below to answer the following questions.

nar001-1.jpg
 

 28. 
Which drawing depicts the electron configuration of neon (mc028-1.jpgNe)?
a.
Drawing A
b.
Drawing B
c.
Drawing C
d.
Drawing D
e.
Drawing E
 

 29. 
Which drawing is of an atom with the atomic number of 6?
a.
Drawing A
b.
Drawing B
c.
Drawing C
d.
Drawing D
e.
Drawing E
 
 
Use the information extracted from the periodic table in the figure below to answer the following questions.

nar002-1.jpg
 

 30. 
How many electrons does nitrogen have in its valence shell?
a.
2
b.
5
c.
7
d.
8
e.
14
 

 31. 
How many neutrons are present in the nucleus of a phosphorus atom?
a.
8
b.
15
c.
16
d.
31
e.
46
 

 32. 
How many electrons does an atom of sulfur have in its valence shell?
a.
4
b.
6
c.
8
d.
16
e.
32
 

 33. 
What is the maximum number of electrons in a 2p orbital of an atom?
a.
1
b.
2
c.
3
d.
4
e.
5
 

 34. 
When two atoms are equally electronegative, they will interact to form
a.
equal numbers of isotopes.
b.
ions.
c.
polar covalent bonds.
d.
nonpolar covalent bonds.
e.
ionic bonds.
 

 35. 
A covalent bond is likely to be polar when
a.
one of the atoms sharing electrons is much more electronegative than the other atom.
b.
the two atoms sharing electrons are equally electronegative.
c.
the two atoms sharing electrons are of the same element.
d.
it is between two atoms that are both very strong electron acceptors.
e.
the two atoms sharing electrons are different elements.
 

 36. 
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
a.
a covalent bond
b.
a hydrogen bond
c.
an ionic bond
d.
a hydrophilic bond
e.
a hydrophobic bond
 

 37. 
What determines the cohesiveness of water molecules?
a.
hydrophobic interactions
b.
nonpolar covalent bonds
c.
ionic bonds
d.
hydrogen bonds
e.
both A and C
 

 38. 
What do cohesion, surface tension, and adhesion have in common with reference to water?
a.
All increase when temperature increases.
b.
All are produced by ionic bonding.
c.
All are properties related to hydrogen bonding.
d.
All have to do with nonpolar covalent bonds.
e.
C and D only
 

 39. 
Which of the following is possible due to the high surface tension of water?
a.
Lakes don't freeze solid in winter, despite low temperatures.
b.
A water strider can walk across the surface of a small pond.
c.
Organisms resist temperature changes, although they give off heat due to chemical reactions.
d.
Water can act as a solvent.
e.
The pH of water remains exactly neutral.
 

 40. 
Which of the following is true when an ice cube cools a drink?
a.
Molecule collisions in the drink increase.
b.
Kinetic energy in the drink decreases.
c.
A calorie of heat energy is transferred from the ice to the water of the drink.
d.
The specific heat of the water in the drink decreases.
e.
Evaporation of the water in the drink increases.
 

 41. 
Water's high specific heat is mainly a consequence of the
a.
small size of the water molecules.
b.
high specific heat of oxygen and hydrogen atoms.
c.
absorption and release of heat when hydrogen bonds break and form.
d.
fact that water is a poor heat conductor.
e.
inability of water to dissipate heat into dry air.
 

 42. 
At what temperature is water at its densest?
a.
0°C
b.
4°C
c.
32°C
d.
100°C
e.
212°C
 

 43. 
Ice is lighter and floats in water because it is a crystalline structure in which each water molecule is bonded to a maximum of four other water molecules by which kind of bond?
a.
ionic
b.
hydrogen
c.
covalent
d.
A and C only
e.
A, B, and C
 

 44. 
Why does ice float in liquid water?
a.
The liquid water molecules have more kinetic energy and thus support the ice.
b.
The ionic bonds between the molecules in ice prevent the ice from sinking.
c.
Ice always has air bubbles that keep it afloat.
d.
Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
e.
The crystalline lattice of ice causes it to be denser than liquid water.
 
 
The picture below illustrates a solute molecule surrounded by a hydration shell of water. Use it to answer the following question.

nar003-1.jpg
 

 45. 
Based on your knowledge of the polarity of water molecules, the solute molecule is most likely
a.
positively charged.
b.
negatively charged.
c.
without charge.
d.
hydrophobic.
e.
nonpolar.
 

 46. 
Hydrophobic substances such as vegetable oil are
a.
nonpolar substances that repel water molecules.
b.
nonpolar substances that have an attraction for water molecules.
c.
polar substances that repel water molecules.
d.
polar substances that have an affinity for water.
e.
charged molecules that hydrogen-bond with water molecules.
 

 47. 
One mole (mol) of a substance is
a.
6.02 mc047-1.jpg mc047-2.jpg molecules of the substance.
b.
1 g of the substance dissolved in 1 L of solution.
c.
the largest amount of the substance that can be dissolved in 1 L of solution.
d.
the molecular mass of the substance expressed in grams.
e.
A and D only
 

 48. 
Which of the following solutions has the greatest concentration of hydrogen ions [H+]?
a.
gastric juice at pH 2
b.
vinegar at pH 3
c.
tomato juice at pH 4
d.
black coffee at pH 5
e.
household bleach at pH 12
 

 49. 
Which of the following solutions has the greatest concentration of hydroxide ions [OH-]?
a.
lemon juice at pH 2
b.
vinegar at pH 3
c.
tomato juice at pH 4
d.
urine at pH 6
e.
seawater at pH 8
 

 50. 
Buffers are substances that help resist shifts in pH by
a.
releasing H+ in acidic solutions.
b.
donating H+ to a solution when they have been depleted.
c.
releasing OH- in basic solutions.
d.
accepting H+ when the are in excess.
e.
both B and D
 



 
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