Bsc1010 Chapter 16

Front 1

The concept that offspring can inherit the acquired skills of their parents is called 
A. pangenesis.
B. blending inheritance.
C. particulate inheritance.
D. Lamarck's hypothesis.
E. blending inheritance or Lamarck's hypothesis.

Back 1

E. blending inheritance or Lamarck's hypothesis.

Front 2

What personal characteristics and events in Gregor Mendel's life significantly contributed to his ultimate contribution to the study of inheritance?  
A.  His training in physics and mathematics at the University of Vienna.
B.  He failed his physics exam.
C.  He failed his natural history exam.
D.  He got his teaching license at the age of 21.
E.  He got a job as a substitute teacher and enjoyed it.

Back 2

A. His training in physics and mathematics at the University of Vienna.

Front 3

Mating a purebred Labrador retriever to a purebred poodle to produce "Labradoodles" is an example of 
A. true-breeding.
B. hybridization.
C. self-fertilizing.
D. inbreeding.
E. mixed breeding.

Back 3

B. hybridization.

Front 4

Which of these is NOT a reason that Mendel used pea plants as a model to study inheritance? 
A. There are many varieties with distinct and different characteristics.
B. They cannot self-fertilize.
C. It is easy to control cross-fertilizations.
D. The varieties he chose would show the same variant for a trait in generation after generation.
E. They have large flowers.

Back 4

B. They cannot self-fertilize.

Front 5

Which of the following are incorrectly matched for a single-factor cross? 
A. P generation / true breeding
B. F1 generation / monohybrid
C. F2 generation / result of F1 cross
D. F1 generation / result of P cross
E. F2 generation / result of P cross

Back 5

E. F2 generation / result of P cross

Front 6

A cross of a true-breeding smooth pod and yellow pod plants results in all smooth pod offspring. This indicates that 
A. yellow is dominant and smooth is recessive.
B. smooth is dominant and yellow is recessive.
C. yellow and smooth are not alleles.
D. yellow and smooth are variants of the same gene.
E. two of the answers are correct. Yellow and smooth are variants of the same gene, and smooth is the dominant trait.

Back 6

E. two of the answers are correct. Yellow and smooth are variants of the same gene, and smooth is the dominant trait.

Front 7

Polydactylism is a dominant trait that results in extra fingers and toes in humans. A polydactyl man marries a woman with 10 fingers and toes. They have a child that has a normal number of digits. The phenotype of the man's father is unknown, but his mother has a normal phenotype. What are the genotypes of the married couple? 
A. woman Dd, man dd
B. woman DD, man dd
C. woman dd, man DD
D. woman dd, man Dd
E. woman DD, man Dd or dd

Back 7

D. woman dd, man Dd

Front 8

A cross between two pea plants produces a population of 732 purple and 268 white plants. What is the genotype and phenotype of the parents that produced this population? 
A. both parents heterozygous purple
B. one parent homozygous purple, second parent homozygous white
C. one parent heterozygous purple, second parent heterozygous white
D. one parent heterozygous purple, second parent homozygous white
E. one parent homozygous purple, second parent heterozygous white

Back 8

A. both parents heterozygous purple

Front 9

In humans, having dimples in the cheeks is a dominant trait. If a child has dimples but only one of her parents does, what are the genotypes of her parents? 
A. One parent dd, other parent DD
B. one parent dd, other parent Dd
C. one parent Dd, other parent DD
D. one parent must be DD, the other parent could be either dd or Dd
E. one parent must be dd, the other parent could be either Dd or DD

Back 9

E. one parent must be dd, the other parent could be either Dd or DD

Front 10

A male is heterozygous for the trait that produces freckles on the skin, and he has freckles. If he marries a woman who is also heterozygous for freckles, ______ percent of their children will be freckled and __________ percent of their children will be heterozygous. 
A. 100% freckled, 100% heterozygous
B. 75% freckled, 50% heterozygous
C. 75% freckled, 25% heterozygous
D. 50% freckled, 50% heterozygous
E. 100% freckled, 75% heterozygous

Back 10

B. 75% freckled, 50% heterozygous

Front 11

How can you determine the genotype of a plant showing the dominant phenotype of red color? 
A. The phenotype reflects the genotype, so the plant must be homozygous for the trait.
B. Cross the red plant with a white plant to see if any white plants appear.
C. Cross the red plant with other red plants to see if any white plants appear.
D. Cross the red plant with a white plant to see how many red plants appear.
E. Cross the red plant with another red plant, and then cross the F1 population with each other to see if any white plants appear.

Back 11

B. Cross the red plant with a white plant to see if any white plants appear.

Front 12

The single-factor crosses performed by Mendel support the observation that 
A. the two alleles for a given gene are distributed randomly among an individual's gametes.
B. the two alleles for a given gene are found within the same gamete.
C. if the recessive alleles for two different genes are on the same chromosome, they will never be found within the same gamete.
D. only the dominant alleles for a given trait are found in an organism's gametes.
E. if the dominant alleles for two different genes are on different chromosomes, they will never be found within the same gamete.

Back 12

A. the two alleles for a given gene are distributed randomly among an individual's gametes.

Front 13

The two-factor crosses performed by Mendel support the observation that 
A. alleles for a given trait are distributed randomly among an individual's gametes independent of the alleles for other traits.
B. traits that are encoded by genes on different chromosomes are never found within the same gamete.
C. the F1 generation can display phenotypes in combinations different from those seen in the P generation.
D. the F2 generation will only display phenotypes in the same combinations as the P generation.
E. self-fertilization of the F1 generation will produce 100% heterozygous plants at both loci.

Back 13

A. alleles for a given trait are distributed randomly among an individual's gametes independent of the alleles for other traits.

Front 14

An organism that is heterozygous for two traits can produce a maximum of _______ different gametes for these traits. 
A. 2
B. 4
C. 2; if they are on the same chromosome
D. 4; only if they are on different chromosomes
E. 8

Back 14

B. 4

Front 15

Which of the following INCORRECTLY states a principle of the chromosome theory of inheritance? 
A. Genes are transmitted from parent to offspring via chromosomes.
B. Gametes contain either a maternal or paternal set of chromosomes.
C. Somatic cells contain a maternal and paternal set of chromosomes.
D. The paternal and maternal chromosomes assort randomly during meiosis.
E. Gametes are haploid and somatic cells are diploid.

Back 15

B. Gametes contain either a maternal or paternal set of chromosomes.

Front 16

A homologous pair of sister chromatids will possess _______ copies of the alleles for each locus. 
A. 2
B. 4
C. 8
D. 1
E. 50% of the

Back 16

C. 8

Front 17

Which of the following accurately gives the distribution of phenotypes produced from a cross of purple dwarf pea plants that are heterozygous for flower color and plant height? 
A. 63 purple dwarf; 28 purple tall; 27 white dwarf; 7 white tall
B. 132 purple dwarf; 138 white tall
C. 54 purple dwarf; 6 white tall
D. 100% purple dwarf
E. 27 purple dwarf; 28 purple tall; 31 white dwarf; 29 white tall

Back 17

A. 63 purple dwarf; 28 purple tall; 27 white dwarf; 7 white tall

Front 18

What features of meiosis allow for independent assortment of chromosomes? 
A. random alignment of homologous sister chromatids on the metaphase plate
B. separation of sister chromatids
C. reduction of chromosome number from diploid to haploid
D. both the separation of sister chromatids and the reduction of chromosome number from diploid to haploid
E. All of these features allow for the independent assortment of chromosomes.

Back 18

A. random alignment of homologous sister chromatids on the metaphase plate

Front 19

The probability of obtaining a dominant phenotype from self-fertilization of a heterozygous individual is 
A. 1/4
B. 1/2
C. 3/4
D. 100%

Back 19

C. 3/4

Front 20

The probability of a couple having either a boy or a girl is ½. However, many families have more boys than girls and VICE VERSA. Why is the observed ratio of boys to girls in typical families different than the predicted ratio? 
A. There is a large random sampling error due to the small size of families.
B. There is a small random sampling error due to the small size of families.
C. Humans are more heterozygous than is predicted by random sampling.
D. The sex of each child is determined independently.
E. Two of the answers are correct. There is a large random sampling error due to the small size of human families and the sex of each child is determined independently.

Back 20

E. Two of the answers are correct. There is a large random sampling error due to the small size of human families and the sex of each child is determined independently.

Front 21

A nearsighted woman (Nn) with hazel eyes (Hh) marries a man with normal vision and hazel eyes (Hh). Their three children all have blue eyes and normal vision. What is the probability that their next child will have blue eyes and be nearsighted? 
A. 1/4
B. 1/2
C. 3/8
D. 1/8
E. 5/8

Back 21

C. 3/8

Front 22

Which of the following phrases INCORRECTLY finishes this statement? A genetic disease that causes death in infancy and has an autosomal recessive inheritance pattern can persist in a population because 
A. it can be passed on to the next generation by a heterozygous carrier.
B. the deleterious effects of the disease may not occur until after reproductive age.
C. if both parents are carriers, they have a 50% chance of having normal children.
D. only homozygotes for the abnormal allele will have the disease.
E. individuals with one abnormal allele do not show symptoms of the disease.

Back 22

C. if both parents are carriers, they have a 50% chance of having normal children.

Front 23

A woman comes to your genetic counseling center because she knows that Huntington disease occurs in members of her family. Her paternal grandfather was afflicted, but so far her father shows no symptoms. Her two great-great grandmothers on her father's side were healthy well into their 90s, and one of her great-great grandfathers died of unknown causes at 45. Testing for Huntington disease is extremely expensive, but she is concerned that she may fall victim to this disease and wants to plan her life accordingly. After examining her pedigree you advise her to 
A. not get tested because there is no possibility that she is homozygous.
B. not get tested because only males in her family get the disease.
C. get tested because her father could be a carrier.
D. not get tested because her father is only a carrier and it is very unlikely her mother is a carrier.
E. not get tested because her 40-year-old father shows no symptoms.

Back 23

C. get tested because her father could be a carrier.

Front 24

For mechanisms of sex determination, which of the following is incorrectly paired? 
A. X-Y, cow
B. X-O, grasshopper
C. ZZ-ZW, bluebird
D. 1n-2n, pea plant
E. high temperature-low temperature, alligator

Back 24

D. 1n-2n, pea plant

Front 25

In mammals, males are ________ and females are ____________. 
A. heterozygous, homozygous
B. hemizygous, homozygous
C. homozygous, heterozygous
D. hemizygous, heterozygous
E. heterozygous, hemizygous

Back 25

B. hemizygous, homozygous