Biology (CP) HW Chapter 11 (Due March 28, Test April 1)
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____1.Each pea-plant gamete has how many alleles for the height gene?
a. / 1b. / 2
c. / 3
d. / 4
____2.A mule is the result of a cross between a donkey and a horse. A mule is a
a. / tetrad.b. / phenotype.
c. / genotype.
d. / hybrid.
____3.Gregor Mendel removed the male parts from the flowers of some plants in order to
a. / prevent hybrids from forming.b. / prevent cross-pollination.
c. / stimulate self-pollination.
d. / control crosses between plants.
____4.If a pea plant has a recessive allele for green peas, it will produce
a. / green peas if it also has a dominant allele for yellow peas.b. / both green peas and yellow peas if it also has a dominant allele for yellow peas.
c. / green peas if it does not also have a dominant allele for yellow peas.
d. / yellow peas if it does not also have a dominant allele for green peas.
____5.If a pea plant’s alleles for height are tt, what is true of its parents?
a. / Both parents were tall.b. / Both parents were short.
c. / Both parents contributed a recessive allele.
d. / Both parents contributed a dominant allele.
____6.When Gregor Mendel crossed true-breeding tall plants with true-breeding short plants, why was it impossible to observe segregation?
a. / Alleles for height do not segregate in the F2.b. / Alleles segregate only in the F2 generation.
c. / Alleles segregate best when two tall plants are crossed.
d. / Alleles in the F1 must be Tt to have height variety in the F2.
____7.A tall plant (TT) is crossed with a short plant (Tt). If the tall F1 pea plants are allowed to self-pollinate,
a. / the offspring will be of medium height.b. / all of the offspring will be tall.
c. / all of the offspring will be short.
d. / the offspring can be tall or short.
____8.In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F2 generation because
a. / the allele for shortness becomes more common in the F2 generation.b. / the allele for shortness becomes dominant in the F2 generation.
c. / the alleles for both heights segregated when the F1 plants made gametes.
d. / the alleles for tallness begin to disappear in the F2 generation.
____9.When you flip a coin, what is the probability that it will come up tails?
a. / 1b. / 1/2
c. / 1/4
d. / 1/8
____10.The principles of probability can be used to
a. / predict the traits of the offspring of genetic crosses.b. / determine the actual outcomes of genetic crosses.
c. / determine which species should be used in genetic crosses.
d. / decide which organisms are best to use in genetic crosses.
____11.A heterozygous tall pea plant is crossed with a short plant. The probability that an F1 plant will be tall is
a. / 25%.b. / 50%.
c. / 75%.
d. / 100%.
____12.Organisms that have two identical alleles for a particular trait are said to be
a. / hybrid.b. / homozygous.
c. / heterozygous.
d. / dominant.
Tt
T / t
TT / T / TT / Tt
T / TT / Tt
T / = / Tall
t / = / Short
Figure 11–1
____13.In the Punnett square shown in Figure 11–1, which of the following is true about the offspring resulting from the cross?
a. / About half are expected to be short.b. / All are expected to be short.
c. / About three fourths are expected to be tall.
d. / All are expected to be tall.
____14.What principle states that during gamete formation genes for different traits separate without influencing each other’s inheritance?
a. / principle of dominanceb. / principle of independent assortment
c. / principle of probabilities
d. / principle of segregation
RrYy
RY / Ry / rY / ry
RY / RRYY / RRYy / RrYY / RrYy / Seed Shape
R = Round
r = Wrinkled
RrYy / Ry / RRYy / RRyy / RrYy / Rryy / Seed Color
Y = Yellow
y = Green
rY / RrYY / RrYy / rrYY / rrYy
ry / RrYy / Rryy / rrYy / rryy
Figure 11–2
____15.The Punnett square in Figure 11–2 shows that the gene for pea shape and the gene for pea color
a. / assort independently.b. / are linked.
c. / have the same alleles.
d. / are always homozygous.
____16.How many different allele combinations would be found in the gametes produced by a pea plant whose genotype was RrYY?
a. / 2b. / 4
c. / 8
d. / 16
RrYy / RRYy
RY / Ry / RY / Ry
RY / RRYY / RRYy / RRYY / RRYy
Ry / RRYy / RRyy / RrYy / RRyy
rY / RrYY / RrYy / RrYY / RrYy
ry / RrYy / Rryy / RrYy / Rryy
Figure 11–3
____17.Use Figure 11–3 to answer the following question. If a pea plant that is heterozygous for round, yellow peas (RrYy) is crossed with a pea plant that is homozygous for round peas but heterozygous for yellow peas (RRYy), how many different phenotypes are their offspring expected to show?
a. / 2b. / 4
c. / 8
d. / 16
____18.Why did Thomas Hunt Morgan use fruit flies in his studies?
a. / Fruit flies produce a large number of offspring.b. / Fruit flies take a long time to produce offspring.
c. / Fruit flies share certain characteristics with pea plants.
d. / Fruit flies have a long life span.
____19.A male and female bison that are both heterozygous for normal skin pigmentation (Aa) produce an albino offspring (aa). Which of Mendel’s principles explain(s) why the offspring is albino?
a. / dominance onlyb. / independent assortment only
c. / dominance and segregation
d. / segregation only
____20.Situations in which one allele for a gene is not completely dominant over another allele for that gene are called
a. / multiple alleles.b. / incomplete dominance.
c. / polygenic inheritance.
d. / multiple genes.
____21.A cross of a black chicken (BB) with a white chicken (WW) produces all speckled offspring (BBWW). This type of inheritance is known as
a. / incomplete dominance.b. / polygenic inheritance.
c. / codominance.
d. / multiple alleles.
____22.Variation in human skin color is an example of
a. / incomplete dominance.b. / codominance.
c. / polygenic traits.
d. / multiple alleles.
____23.What determines the color of western white butterflies?
a. / genes alone.b. / the environment alone
c. / temperature and genes
d. / exposure to sunlight and genes
____24.The arctic fox is blue-gray in the summer and white in the winter. What most likely influence(s) this change?
a. / genes and the environmentb. / dominant alleles
c. / the environment alone
d. / codominant alleles
____25.The number of chromosomes in a gamete is represented by the symbol
a. / Z.b. / X.
c. / N.
d. / Y.
____26.If an organism’s diploid number is 12, its haploid number is
a. / 12.b. / 6.
c. / 24.
d. / 3.
____27.Gametes have
a. / homologous chromosomes.b. / twice the number of chromosomes found in body cells.
c. / two sets of chromosomes.
d. / one allele for each gene.
____28.Gametes are produced by the process of
a. / mitosis.b. / meiosis.
c. / crossing-over.
d. / replication.
Figure 11–4
____29.What is shown in Figure 11–4?
a. / independent assortmentb. / anaphase I of meiosis
c. / crossing-over
d. / replication
____30.Chromosomes form tetrads during
a. / prophase I of meiosis.b. / metaphase I of meiosis.
c. / interphase.
d. / anaphase II of meiosis.
____31.What reduces the number of chromosomes during meiosis?
a. / Crossing-over occurs.b. / Metaphase occurs.
c. / Replication occurs twice.
d. / Replication does not occur.
____32.Unlike mitosis, meiosis results in the formation of
a. / diploid cells.b. / haploid cells.
c. / 2N daughter cells.
d. / body cells.
____33.What is formed at the end of meiosis?
a. / two genetically identical cellsb. / four genetically different cells
c. / four genetically identical cells
d. / two genetically different cells
____34.At the end of meiosis, there are
a. / two haploid daughter cells.b. / four haploid daughter cells.
c. / two diploid daughter cells.
d. / four diploid daughter cells.
____35.Which of the following assort independently?
a. / chromosomesb. / linked genes
c. / multiple alleles
d. / codominant alleles
____36.Linked genes
a. / are never separated.b. / assort independently.
c. / are on the same chromosome.
d. / are always recessive.
Gene Map of Chromosome 2 of the Fruit Fly
Figure 11–5
____37.Which trait is most likely linked to having a curved wing in the fruit fly in Figure 11–5?
a. / dumpy wingb. / vestigial wing
c. / arc (bent wings)
d. / speck wing
____38.Gene maps are based on
a. / the frequencies of crossing-over.b. / independent assortment.
c. / genetic diversity.
d. / the number of genes in a cell.
____39.If two genes are on the same chromosome and rarely assort independently,
a. / crossing-over never occurs between the genes.b. / crossing-over always occurs between the genes.
c. / the genes are probably located far apart from each other.
d. / the genes are probably located close to each other.
____40.The farther apart two genes are located on a chromosome, the
a. / less likely they are to be inherited together.b. / more likely they are to be linked.
c. / less likely they are to assort independently.
d. / less likely they are to be separated by crossing over.
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____41.A trait is a specific characteristic that varies from one individual to another. ______
____42.True-breeding plants that produced axial flowers were crossed with true-breeding plants that produced terminal flowers. The resulting offspring all produced terminal flowers because the allele for terminal flowers is recessive. ______
____43.During the formation of gametes in a hybrid tall plant, the tall allele and the short allele stay together. ______
____44.The principles of probability can explain the numerical results of Mendel’s experiments. ______
____45.The probability that a gamete produced by a pea plant heterozygous for stem height (Tt) will contain the recessive allele is 100%. ______
____46.If Mendel had found that an F2 cross of plants that were heterozygous for two traits had made offspring with two phenotypes, this finding would have supported the theory of independent assortment. ______
____47.If two speckled chickens are mated, according to the principle of codominance, 25% of the offspring are expected to be speckled. ______
____48.Coat color in rabbits is determined by a single gene that has multiple alleles. ______
____49.If an organism has four linkage groups, it has eight chromosomes. ______
____50.Genes in the same linkage group are usually inherited separately. ______
Completion
Complete each statement.
51.The plants that Gregor Mendel crossed to produce the F1 generation made up the ______generation.
52.Due to the process of segregation, alleles separate during the production of ______.
53.An organism has 38 chromosomes in a body cell. After mitosis each cell has 38 chromosomes. After meiosis each gamete has ______chromosomes.
54.What is the probability of flipping a coin and getting heads 5 times in a row?
TtT / t
TT / T / TT / Tt
T / TT / Tt
T / = / Tall
t / = / Short
Figure 11–1
55.In the Punnett square shown in Figure 11–1, the genotypes of the offspring are ______.
56.The principle of independent assortment states that ______for different traits can segregate independently during the formation of gametes.
57.If pea plants that are homozygous for round, yellow seeds (RRYY) were crossed with pea plants that are heterozygous for round, yellow seeds (RrYy), the expected phenotype(s) of the offspring would be ______.
58.______’s principles can be used to study heredity in dogs, cats and sheep.
59.The reddish-brown pigment that gives color to a fruit-fly’s eye is controlled by three genes, so a fruit fly’s eye color is a ______.
60.The characteristics of an organism are determined by two factors: ______.