Category: My Classroom Material

Diffusion Across Membranes

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Diffusion Across membranes

1. Which of the following is NOT a type of passive transport?
diffusion
osmosis
endocytosis
facilitated diffusion

2. Chamber A contains 40% helium and Chamber B contains 20% helium. Chambers are connected by a tube the molecules are free to cross. Which of the following will occur?
some helium will move from chamber A to chamber B
some helium will move from chamber B to chamber A
helium will remain concentrated in chamber A
all of the helium will move into chamber B

3. What will happen to an animal cell placed in a salt water solution?
The cell will shrink
the cell will expand
the cell will burst
the cell will shrink and then expand and then shrink again

4. An animal cell placed in a hypotonic solution will:
die
take on water
lose water
divide

5. Which of the following is a type of active transport?
sodium potassium pump
endocytosis
exocytosis
all of these

6. Active transport requires:
a concentration gradient
osmosis
energy
a hypertonic solution

Score =
Correct answers:

Study Guide Cellular Respiration

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Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
When cells break down food molecules, energy
a.
 is released all at once.
b.
 is released entirely as body heat into the environment.
c.
 is temporarily stored in ATP molecules.
d.
 causes excitation of electrons in chlorophyll molecules.
 2.
ATP
a.
 contains five phosphate groups.
b.
 is essential for a cell to perform all the tasks necessary for life.
c.
 is found only in bacteria.
d.
 All of the above
 3.
A substance produced during photosynthesis that is used for completion of cellular respiration is
a.
 water.
c.
 NADPH.
b.
 ATP.
d.
 oxygen.
 4.
The process of cellular respiration
a.
 is performed only by organisms that are incapable of photosynthesis.
b.
 breaks down food molecules to release stored energy.
c.
 occurs before plants are able to carry out photosynthesis.
d.
 occurs only in animals.
 5.
cellular respiration : organic compounds ::
a.
 light bulb : glass
c.
 automobile : gasoline
b.
 trunk : clothing
d.
 country : nation
 6.
When glycolysis occurs,
a.
 a molecule of glucose is split.
b.
 two molecules of pyruvic acid are made.
c.
 some ATP is produced.
d.
 All of the above
 7.
The name of the process that takes place when organic compounds are broken down in the absence of oxygen is
a.
 respiration.
c.
 fermentation.
b.
 oxidation.
d.
 All of the above
 8.
When muscles are exercised extensively in the absence of sufficient oxygen,
a.
 a large amount of ATP is formed.
b.
 NADH molecules split.
c.
 lactic acid is produced.
d.
 cellular respiration ceases.
 9.
You have been growing some animal cells in culture. The cells grow well for several weeks, and then their growth slows down. You conduct some tests and determine that there is a lot of lactic acid in the culture fluid. Which of the following is the most likely explanation for the poor growth of the cells?
a.
 There is too much glucose in the culture fluid.
b.
 There is not enough glucose in the culture fluid.
c.
 There is too much oxygen in the culture fluid.
d.
 There is not enough oxygen in the culture fluid.
 10.
If the formation of a standard amount of ATP under certain conditions requires 12 kcal of energy and the complete oxidation of glucose yields 686 kcal of energy, how efficient is glycolysis at extracting energy from glucose?
a.
 1.7%
c.
 7.0%
b.
 3.5%
d.
 35%
 11.
Cellular respiration takes place in two stages:
a.
 glycolysis and fermentation.
b.
 Stage 1 and Stage 2 of photosynthesis.
c.
 glycolysis, then aerobic respiration.
d.
 aerobic respiration, then glycolysis.
 12.
In cellular respiration, a two-carbon molecule combines with a four-carbon molecule to form citric acid as part of
a.
 glycolysis.
b.
 carbon fixation.
c.
 the Krebs cycle.
d.
 the electron transport chain.
 13.
Acetyl coenzyme A
a.
 is formed from the breakdown of pyruvic acid.
b.
 enters the Krebs cycle.
c.
 can be used in synthesis of needed molecules.
d.
 All of the above
 14.
Glycolysis and aerobic respiration are different in that
a.
 glycolysis occurs on the cell membrane, while aerobic respiration occurs in mitochondria.
b.
 glycolysis occurs only in photosynthesis, while aerobic respiration is part of cellular respiration.
c.
 glycolysis occurs in the absence of oxygen, while aerobic respiration requires oxygen.
d.
 There is no difference; these terms are different names for the same process.
 15.
Which of the following is not formed during the Krebs cycle?
a.
 CO2
c.
 NADH
b.
 FADH2
d.
 NADPH
 16.
Which of the following is not part of cellular respiration?
a.
 electron transport
c.
 the Krebs cycle
b.
 glycolysis
d.
 the Calvin cycle
 17.
With oxygen present, the Krebs cycle and the electron transport chain
a.
 provide organisms an alternative to glycolysis.
b.
 produce most of the ATP needed for life.
c.
 break down glucose to produce carbon dioxide, water, and ATP.
d.
 All of the above
 18.
Water is an end product in
a.
 lactic acid formation.
c.
 the Krebs cycle.
b.
 fermentation.
d.
 the electron transport chain.
 19.
Krebs cycle : CO2 ::
a.
 glycolysis : glucose
b.
 acetyl CoA formation : O2
c.
 cellular respiration : O2
d.
 electron transport chain : ATP
 20.
ATP molecules produced during aerobic respiration
a.
 remain in the mitochondria in which they are formed.
b.
 are stored in chloroplasts of the same cell in which they are formed.
c.
 enter the cell’s cytoplasm through the membranes of the mitochondria in which they are formed.
d.
 are distributed by the bloodstream to all cells in the body.
 21.
At the end of the electron transport chain,
a.
 the electrons combine with oxygen and protons to form water.
b.
 the electrons are used in the formation of ethyl alcohol.
c.
 the electrons build up inside the mitochondria and diffuse back to a thylakoid.
d.
 None of the above
C6 H12O6 + 6O2 + ADP + P ® 6CO2 + 6 H2O + MOLECULE A
 22.
The process shown in the equation above begins in the cytoplasm of a cell and ends in the
a.
 cytoplasm.
c.
 endoplasmic reticulum.
b.
 mitochondria.
d.
 lysosome.
 23.
The equation above summarizes the process known as
a.
 photosynthesis.
c.
 cellular respiration.
b.
 fermentation.
d.
 protein breakdown.
 24.
The molecule referred to as “molecule A” in the equation above is
a.
 NADPH.
c.
 NADH.
b.
 ATP.
d.
 ADP.
 25.
When living cells break down molecules, energy is
a.
 stored as ADP.
c.
 released as heat.
b.
 stored as ATP.
d.
 Both b and c
 26.
Which of the following is the best explanation for the presence of both chloroplasts and mitochondria in plant cells?
a.
 In the light, plants are photosynthetic autotrophs. In the dark, they are heterotrophs.
b.
 If plants cannot produce enough ATP in the process of photosynthesis to meet their energy needs, they can produce it in aerobic respiration.
c.
 Sugars are produced in chloroplasts. These sugars can be stored in the plant for later use, converted to other chemicals, or broken down in aerobic respiration to yield ATP for the plant to use to meet its energy needs.
d.
 The leaves and sometimes the stems of plants contain chloroplasts, which produce ATP to meet the energy needs of these plant parts. The roots of plants contain mitochondria, which produce ATP to meet the energy needs of these plant parts.
 27.
In cellular respiration, the most energy is transferred during
a.
 glycolysis.
b.
 lactic acid fermentation.
c.
 the Krebs cycle.
d.
 the electron transport chain
 28.
Electrons are donated to the electron transport chain by
a.
 ATP and NADH.
c.
 ATP and NAD+.
b.
 FADH2 and NADH.
d.
 NAD+ and ATP.
 29.
If the formation of 38 molecules of ATP requires 266 kcal of energy and the complete oxidation of glucose yields 686 kcal of energy, how efficient is cellular respiration at extracting energy from glucose?
a.
 20%
c.
 25%
b.
 39%
d.
 100%
 

Completion
Complete each statement.
 30.
During fermentation, either ethyl alcohol and carbon dioxide or ____________________ is formed.
 31.
Of the maximum possible yield of 38 ATP molecules produced by the complete oxidation of one glucose molecule, ____________________ molecules of ATP are produced during glycolysis.
 32.
The Krebs cycle takes place in the _________________________.
 

Essay
 33.
The relationship between photosynthesis and cellular respiration is usually described as a cycle. Briefly explain. Write your answer in the space below.

 
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Study Guide Photosynthesis

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Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
Energy is required for a variety of life processes including
a.
 growth and reproduction.
b.
 movement.
c.
 transport of certain materials across cell membranes.
d.
 All of the above
 2.
Heterotrophs are organisms that can
a.
 produce food from inorganic molecules and sunlight.
b.
 survive without energy.
c.
 consume other organisms for energy.
d.
 carry out either photosynthesis or chemosynthesis.
 3.
Based on the cycle of photosynthesis and cellular respiration, one can say that the ultimate original source of energy for all living things on Earth is
a.
 glucose.
c.
 the sun.
b.
 water.
d.
 carbon dioxide.
 4.
The process whereby plants capture energy and make complex molecules is known as
a.
 homeostasis.
c.
 photosynthesis.
b.
 evolution.
d.
 development.
 5.
Suspended in the fluid stroma of chloroplasts are
a.
 organelles called eukaryotes.
b.
 numerous mitochondrial membranes.
c.
 small coins that provide energy.
d.
 stacks of thylakoids called grana.
 6.
photosynthesis : oxygen ::
a.
 respiration : darkness
b.
 light reactions : dark reactions
c.
 respiration : carbon dioxide
d.
 oxygen : carbon dioxide
 7.
biochemical pathway : reaction ::
a.
 barrier : wall
b.
 match : burn
c.
 theater : drama
d.
 assembly line : workers
 8.
light reactions : thylakoids ::
a.
 grana : thylakoids
b.
 grana : ATP
c.
 Calvin cycle : stroma
d.
 stroma : grana of chloroplast
 9.
The sun is considered the ultimate source of energy for life on Earth because
a.
 all organisms carry out photosynthesis.
b.
 all organisms carry out cellular respiration.
c.
 either photosynthetic organisms or organisms that have eaten them provide energy for all other organisms on Earth.
d.
 the sun heats Earth’s atmosphere.
 10.
The energy from the sun is converted into chemical energy in the form of organic compounds in a series of linked chemical reactions called a
a.
 photosynthetic reactant.
b.
 ATP generator.
c.
 chemical equation.
d.
 biochemical pathway.
 11.
The role of chlorophyll in photosynthesis is to
a.
 absorb light energy.
b.
 pass electrons to carotenoids.
c.
 split water molecules.
d.
 All of the above
 12.
When light strikes an object, the light may be
a.
 reflected.
c.
 transmitted.
b.
 absorbed.
d.
 All of the above
 13.
Chlorophyll is green because
a.
 it absorbs green wavelengths of light.
b.
 it absorbs blue and yellow wavelengths, which make green.
c.
 it reflects green wavelengths of light.
d.
 it transmits light and causes an optical illusion.
 14.
What happens when a chlorophyll molecule absorbs light?
a.
 Some of its electrons are raised to a higher energy level.
b.
 It disintegrates, giving off huge amounts of heat.
c.
 It glows, radiating green light and giving the plant a green appearance.
d.
 It attracts electrons from other molecules.
 15.
chloroplast : grana ::
a.
 photosystem : pigment molecules
b.
 chlorophyll : pigments
c.
 thylakoids : photosynthesis
d.
 chlorophyll : green
 16.
When electrons of a chlorophyll molecule are raised to a higher energy level,
a.
 they become a particle of light.
b.
 they form a glucose bond.
c.
 they enter an electron transport chain.
d.
 they enter the Calvin cycle.
 17.
NADP+ is important in photosynthesis because it
a.
 becomes oxidized to form NADP.
b.
 is needed to form chlorophyll.
c.
 provides additional oxygen atoms.
d.
 provides protons and electrons for some reactions.
 18.
The electrons of photosystem I
a.
 are eventually replaced by electrons from photosystem II.
b.
 attach to water molecules during the light reaction.
c.
 are at the end of the electron transport chain.
d.
 are absorbed by oxygen molecules to form water.
 19.
The source of oxygen produced during photosynthesis is
a.
 carbon dioxide.
c.
 chlorophyll.
b.
 water.
d.
 glucose.
 20.
The major atmospheric byproduct of photosynthesis is
a.
 nitrogen.
c.
 water.
b.
 carbon dioxide.
d.
 oxygen.
 21.
During the Calvin cycle, carbon-containing molecules are produced from
a.
 carbon atoms from ATP.
b.
 carbon atoms, hydrogen atoms, and oxygen atoms from glucose.
c.
 carbon atoms from carbon dioxide in the air and hydrogen atoms from water.
d.
 carbon atoms from carbon dioxide in the air and hydrogen atoms from NADPH.
 22.
Which of the following processes occurs in the thylakoid membrane and converts captured light energy into chemical energy?
a.
 the Calvin cycle
c.
 light absorption
b.
 ATP synthase
d.
 chemiosmosis
 23.
Chemiosmosis in the thylakoid membrane is directly responsible for
a.
 adding protons to NADP+.
b.
 providing the energy to produce ATP molecules.
c.
 producing ATP-synthetase.
d.
 generating glucose molecules.
 24.
At the thylakoid membrane,
a.
 electrons return to their original energy levels.
b.
 electrons are pushed out of the thylakoid.
c.
 energy from electrons is used to make glucose.
d.
 the thylakoid bursts, releasing energy.
 25.
Products of the light reactions of photosynthesis that provide energy for the Calvin cycle are
a.
 oxygen and ATP.
c.
 ATP and NADPH.
b.
 water and oxygen.
d.
 oxygen and NADPH.
 26.
The Calvin cycle of photosynthesis
a.
 requires ATP and NADPH.
b.
 can occur in both light and dark conditions.
c.
 generates glucose.
d.
 All of the above
 27.
The energy used in the Calvin cycle for the production of carbohydrate molecules comes from
a.
 ATP made during cellular respiration.
b.
 the Krebs cycle.
c.
 ATP made in the light reactions of photosynthesis.
d.
 CO2 absorbed during the last stage of photosynthesis.
 28.
During photosynthesis, the series of reactions that create the complex carbohydrates needed for energy and growth is called
a.
 the Calvin cycle.
b.
 the Krebs cycle.
c.
 the light reactions.
d.
 the electron transport chain.
 29.
All organic molecules contain carbon atoms that ultimately can be traced back in the food chain to
a.
 the bodies of heterotrophs.
b.
 carbon dioxide from the atmosphere.
c.
 water absorbed by plants.
d.
 the carbon that comes from the sun.
 30.
Which of the following can be produced from the products of the Calvin cycle?
a.
 carbohydrates
c.
 proteins
b.
 lipids
d.
 All of the above
 31.
C3, C4, and CAM plants differ from each other in that
a.
 C3 plants use the Calvin cycle for carbon fixation and C4 and CAM plants use different pathways for carbon fixation.
b.
 C3 plants have their stomata open during the day and C4 and CAM plants have their stomata open only at night.
c.
 C3 and C4 plants have their stomata open during the day and CAM plants have their stomata open only at night.
d.
 C3 plants use CO2 to form organic compounds and C4 and CAM plants use other sources of carbon.
nar001-1.jpg
 32.
Refer to the illustration above. Graph 1 demonstrates that the rate of photosynthesis
a.
 decreases in response to increasing light intensity.
b.
 increases indefinitely in response to increasing light intensity.
c.
 increases in response to increasing light intensity, but only to a certain point.
d.
 is unaffected by changes in light intensity.
 33.
Refer to the illustration above. Taken together, these graphs demonstrate that
a.
 photosynthesis is independent of environmental influences.
b.
 increases in light intensity cause increases in temperature.
c.
 as the rate of photosynthesis increases, the temperature of the plant eventually decreases.
d.
 the rate of photosynthesis is affected by changes in the plant’s environment.
 

Essay
 34.
Why do the cells of plant roots generally lack chloroplasts? Write your answer in the space below.
 35.
Define the terms autotroph and heterotroph. What types of organisms belong in each of these categories? Write your answer in the space below.

 
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Genetics Practice Test

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Multiple Choice
Identify the choice that best completes the statement or answers the question.
 1.
Mendel prevented self-pollination of his plants by
a.
 growing only one kind of plant.
b.
 preventing crossing-over.
c.
 removing the anthers of the plants.
d.
 removing the stigmas of the plants.
 2.
The “father” of genetics was
a.
 T. A. Knight.
c.
 Gregor Mendel.
b.
 Hans Krebs.
d.
 None of the above
 3.
Mendel obtained his P generation by allowing the plants to
a.
 self-pollinate.
c.
 assort independently.
b.
 cross-pollinate.
d.
 segregate.
 4.
What is the probability that the offspring of a homozygous dominant individual and a homozygous recessive individual will exhibit the dominant phenotype?
a.
 0.25
c.
 0.66
b.
 0.5
d.
 1.0
 5.
True-breeding pea plants always
a.
 are pollinated by hand.
b.
 produce offspring each of which can have multiple forms of a trait.
c.
 produce offspring each of which can have only one form of a trait.
d.
 are heterozygous.
 6.
The first filial (F1) generation is the result of
a.
 cross-pollination among parents and the next generation.
b.
 crosses between individuals of the parental generation.
c.
 crosses between the offspring of a parental cross.
d.
 self-fertilization between parental stock.
 7.
Which of the following is the designation for Mendel’s original pure strains of plants?
a.
 P
c.
 F1
b.
 P1
d.
 F2
 8.
F2 : F1 ::
a.
 P : F1
c.
 F1 : P
b.
 F1 : F2
d.
 dominant trait : recessive trait
 9.
The passing of traits from parents to offspring is called
a.
 genetics.
c.
 development.
b.
 heredity.
d.
 maturation.
 10.
A genetic trait that appears in every generation of offspring is called
a.
 dominant.
c.
 recessive.
b.
 phenotypic.
d.
 superior.
 11.
homozygous : heterozygous ::
a.
 heterozygous : Bb
c.
 BB : Bb
b.
 probability : predicting chances
d.
 homozygous : BB
 12.
Mendel’s finding that the inheritance of one trait had no effect on the inheritance of another became known as the
a.
 law of dominance.
b.
 law of universal inheritance.
c.
 law of separate convenience.
d.
 law of independent assortment.
 13.
To describe how traits can disappear and reappear in a certain pattern from generation to generation, Mendel proposed
a.
 the law of independent assortment.
b.
 the law of segregation.
c.
 the law of genotypes.
d.
 that the F2 generation will produce only purple flowers.
 14.
The law of segregation explains that
a.
 alleles of a gene separate from each other during meiosis.
b.
 different alleles of a gene can never be found in the same organism.
c.
 each gene of an organism ends up in a different gamete.
d.
 each gene is found on a different molecule of DNA.
 15.
When Mendel crossed pea plants that differed in two characteristics, such as flower color and plant height,
a.
 these experiments led to his law of segregation.
b.
 he found that the inheritance of one trait did not influence the inheritance of the other trait.
c.
 he found that the inheritance of one trait influenced the inheritance of the other trait.
d.
 these experiments were considered failures because the importance of his work was not recognized.
 16.
The phenotype of an organism
a.
 represents its genetic composition.
b.
 reflects all the traits that are actually expressed.
c.
 occurs only in dominant pure organisms.
d.
 cannot be seen.
 17.
If an individual has two recessive alleles for the same trait, the individual is said to be
a.
 homozygous for the trait.
b.
 haploid for the trait.
c.
 heterozygous for the trait.
d.
 mutated.
 18.
An individual heterozygous for a trait and an individual homozygous recessive for the trait are crossed and produce many offspring. These offspring are likely to be
a.
 all the same genotype.
b.
 of two different phenotypes.
c.
 of three different phenotypes.
d.
 all the same phenotype.
 19.
Tallness (T) is dominant over shortness (t) in pea plants. Which of the following represents the genotype of a pea plant that is heterozygous for tallness?
a.
 T
c.
 Tt
b.
 TT
d.
 tt

In humans, having freckles (F) is dominant over not having freckles (f). The inheritance of these traits can be studied using a Punnett square similar to the one shown below.

nar001-1.jpg
 20.
Refer to the illustration above. The genotype represented in box 1 in the Punnett square would
a.
 be homozygous for freckles.
b.
 have an extra freckles chromosome.
c.
 be heterozygous for freckles.
d.
 have freckles chromosomes.
 21.
Refer to the illustration above. The genotype in box 3 of the Punnett square is
a.
 FF.
c.
 ff.
b.
 Ff.
d.
 None of the above
 22.
A trait that occurs in 450 individuals out of a total of 1,800 individuals occurs with a probability of
a.
 0.04.
c.
 0.50.
b.
 0.25.
d.
 0.75.
 23.
How many different phenotypes can be produced by a pair of codominant alleles?
a.
 1
c.
 3
b.
 2
d.
 4
nar002-1.jpg
 24.
Refer to the illustration above. The phenotype represented by box 1 is
a.
 green, inflated.
c.
 yellow, inflated.
b.
 green, constricted.
d.
 yellow, constricted.
 25.
Refer to the illustration above. The genotype represented by box 2 is
a.
 GgIi.
c.
 GI.
b.
 GGIi.
d.
 Gi.
 26.
2,000 yellow seeds : 8,000 total seeds ::
a.
 1 : 6
c.
 1 : 3
b.
 1 : 8
d.
 1 : 4

In rabbits, black fur (B) is dominant over brown fur (b). Consider the following cross between two rabbits.

nar003-1.jpg
 27.
Refer to the illustration above. The device shown, which is used to determine the probable outcome of genetic crosses, is called a
a.
 Mendelian box.
c.
 genetic graph.
b.
 Punnett square.
d.
 phenotypic paradox.
 28.
Refer to the illustration above. Both of the parents in the cross are
a.
 black.
b.
 brown.
c.
 homozygous dominant.
d.
 homozygous recessive.
 29.
Refer to the illustration above. The phenotype of the offspring indicated by box 3 would be
a.
 brown.
b.
 black.
c.
 a mixture of brown and black.
d.
 The phenotype cannot be determined.
 30.
Refer to the illustration above. The genotypic ratio of the F1 generation would be
a.
 1:1.
c.
 1:3.
b.
 3:1.
d.
 1:2:1.
 31.
What is the expected genotypic ratio resulting from a homozygous dominant ´ heterozygous monohybrid cross?
a.
 1:0
c.
 1:2:1
b.
 1:1
d.
 1:3:1
 32.
What fraction of the offspring resulting from a heterozygous ´ heterozygous dihybrid cross are homozygous recessive for both traits?
a.
 9/16
c.
 3/16
b.
 1/4
d.
 1/16
 33.
What is the expected genotypic ratio resulting from a heterozygous ´ heterozygous monohybrid cross?
a.
 1:2:1
c.
 1:2
b.
 1:3:1
d.
 1:0
 34.
What is the expected phenotypic ratio resulting from a homozygous dominant ´ heterozygous monohybrid cross?
a.
 1:3:1
c.
 2:1
b.
 1:2:1
d.
 1:0
nar004-1.jpg
 35.
Refer to the illustration above. The phenotype represented by box 1 is
a.
 round, yellow.
c.
 wrinkled, yellow.
b.
 round, green.
d.
 wrinkled, green.
 36.
Refer to the illustration above. The genotype represented by box 2 is
a.
 RRYY.
c.
 RrYy.
b.
 RrYY.
d.
 rrYy.
 37.
Refer to the illustration above. Which of the following boxes represents the same phenotype as box 7?
a.
 3
c.
 5
b.
 4
d.
 6
 38.
An organism that has inherited two of the same alleles of a gene from its parents is called
a.
 hereditary.
c.
 homozygous.
b.
 heterozygous.
d.
 a mutation.
 39.
In pea plants, yellow seeds are dominant over green seeds. What would be the expected genotype ratio in a cross between a plant with green seeds and a plant that is heterozygous for seed color?
a.
 1:3
c.
 4:1
b.
 1:2:1
d.
 1:1
 40.
codominance : both traits are displayed ::
a.
 probability : crosses
b.
 heterozygous : alleles are the same
c.
 homozygous : alleles are the same
d.
 Punnett square : chromosomes combine
 41.
The difference between a monohybrid cross and a dihybrid cross is that
a.
 monohybrid crosses involve traits for which only one allele exists, while dihybrid traits involve two alleles.
b.
 monohybrid crosses involve self-pollination, while dihybrid crosses involve cross-pollination.
c.
 monohybrid crosses involve one trait; dihybrid crosses involve two traits.
d.
 dihybrid crosses require two Punnett squares; monohybrid crosses need only one.
 42.
What fraction of the offspring resulting from a heterozygous ´ heterozygous dihybrid cross are heterozygous for both traits?
a.
 9/16
c.
 3/16
b.
 1/4
d.
 1/16
 43.
A cross of two individuals for a single contrasting trait is called
a.
 monohybrid.
c.
 dominant.
b.
 dihybrid.
d.
 codominant.
 

Completion
Complete each statement.
 44.
The transferring of pollen between plants is called ____________________.
 45.
Mendel produced true-breeding strains of pea plants through the process of ____________________.
 46.
When two members of the F1 generation are allowed to breed with each other, the offspring are referred to as the ____________________ generation.
 47.
In heterozygous individuals, only the ____________________ allele achieves expression.
 48.
The statement that the members of each pair of alleles separate when gametes are formed is known as the _________________________.
 49.
Different forms of a particular gene, which Mendel called factors, are now called ____________________.
 50.
The cellular process that results in the segregation of Mendel’s factors is ____________________.
 51.
The portion of a DNA molecule containing the coded instructions that result in a particular characteristic of an organism is called a(n) ____________________.
 52.
An organism’s ____________________ refers to the set of alleles it has inherited.
 53.
The likelihood that a specific event will occur is called ____________________.
 54.

co054-1.jpg

Refer to the illustration above. The box labeled “X” represents the phenotype ____________________.
 55.
A fractional probability of 1/2 is the same as a decimal probability of ____________________.

In pea plants, tallness (T) is dominant over shortness (t). Crosses between plants with these traits can be analyzed using a Punnett square similar to the one shown below.

nar005-1.jpg
 56.
Refer to the illustration above. The parents shown in the Punnett square are likely to have offspring with a genotype ratio of ____________________.
 57.
Refer to the illustration above. Box 2 and box ____________________ in the Punnett square represent plants that would be heterozygous for tallness.
 58.
Refer to the illustration above. The phenotype of the plant that would be represented in box 4 of the Punnett square would be ____________________.
 59.
Refer to the illustration above. The genotype of both parents shown in the Punnett square above is ____________________.
 60.
A situation in which both alleles for a trait are expressed in a heterozygous offspring is called ____________________.
 61.
A pattern of heredity in which a heterozygous individual has a phenotype that is intermediate between the phenotypes of its two homozygous parents is called _________________________.
 62.
A table used to determine and diagram the results of a genetic cross is called a ____________________.
 63.
In genetics, lowercase letters are usually used to indicate ____________________.
 

Problem
 64.
In tomato plants, tallness is dominant over dwarfness and hairy stems are dominant over hairless stems. True-breeding (homozygous) plants that are tall and have hairy stems are available. True-breeding (homozygous) plants that are dwarf and have hairless stems are also available. Design an experiment to determine whether the genes for height and hairiness of stem are on the same or different chromosomes. Explain how you will be able to determine from the results whether the genes are on the same chromosome or different chromosomes, and whether they are close to each other or far apart if they are on the same chromosome. Write your answer in the space below.
 65.

A scientist crossed true-breeding tall and hairy-stemmed tomato plants with true-breeding dwarf and hairless-stemmed tomato plants. He found that all of the F1 plants produced as a result of this cross were tall and hairy-stemmed. He then allowed the F1 plants to pollinate each other and obtained 1000 F2 plants. Of these 1000 F2 plants, he observed the following numbers of four different phenotypes:

557 tall and hairy-stemmed plants 192 dwarf and hairy-stemmed plants
180 tall and hairless-stemmed plants 71 dwarf and hairless-stemmed plants

Write your answers to the following in the space below or on a separate sheet of paper.

a.      Which height characteristic is dominant, tallness or dwarfness?
b.      Which stem characteristic is dominant, hairiness or hairlessness?
c.      What are the genotypes of the original, true-breeding parents? (Be sure to indicate what the symbols you use stand for.)
d.      What are the genotypes of the F1 hybrid plants? (Be sure to indicate what the symbols you use stand for.)
e.      What are the genotypes of the four types of plants found in the F2 generation? (Be sure to indicate what the symbols you use stand for.)
f.      What were the expected numbers of plants of each type in the F2 generation? (Round off to the nearest whole numbers.)
g.      Why did the observed numbers of plants of each type in the F2 generation differ from the expected?
h.      How could this experiment have been changed to obtain numbers of plants of each type in the F2 generation that were closer to the expected numbers?
 

Essay
 66.
How might you go about determining the genotype of a red-flowering plant where red is dominant over white? Write your answer in the space below.
 67.
Describe pollination in pea plants. Write your answer in the space below.
 68.
In what ways did Mendel’s methods help ensure his success in unraveling the mechanics of heredity? Write your answer in the space below.
 69.
What conclusions did Gregor Mendel reach based on his observations of pea plants? Write your answer in the space below.
 70.
Describe Mendel’s observation regarding independent assortment. Write your answer in the space below.
 71.
What are three ways to express the probability of an event that occurs 500 times out of 2,000 total trials? Write your answer in the space below.
 72.
Describe how genotype and phenotype are related, and give an example. Write your answer in the space below.
 73.
Explain what is meant by homozygous and heterozygous, and give an example of each. Write your answer in the space below.
 74.
All of the offspring resulting from a cross between a red snapdragon and a white snapdragon are pink. What is a possible explanation for this? Write your answer in the space below.

 
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Transcription and Translation Tool

%CODE1%

Transcription and Translation Tool Converts DNA to RNA to protein.

DNA sequence:
RNA sequence:
 Protein sequence:
DNA (deoxyribonucleic acid)

  • a permanent copy of genetic information.
  • uses “T” instead of “U”
  • no 2′ OH group
  • more stable than RNA
  • lower error frequency during replication than RNA
RNA (ribonucleic acid)

  • messenger RNA (mRNA) is a temporary copy of the gene sequence in which protein is encoded.
Protein

  • consists of amino acids linked by aminoester (“peptide”) bonds.
  • most enzymes and many structural components of cells are made of proteins.