Warm Up Quiz

Question 1

In a plant in which 2n = 24, what is the total number of chromatids present during prophase of mitosis?

a) 6
b) 12
c) 24
d) 48
e) 96

Answer 1

d) 48

Question 2

Which of the following is true of mitosis but not meiosis

a) Chromatid formation
b) Cell division
c) Formation of diploid daughter cells
d) Separation of homologous centromeres to opposite poles
e) Chromosome condensation (shortening)

Answer 2

c) Formation of diploid daughter cells

Question 3

The genetic makeup of an organism is its

a) phenotype.
b) prototype.
c) phenocopy.
d) genotype.
e) heterotype.

Answer 3

d) genotype.

Question 4

The first filial generation is produced by mating the

a) F1 offspring.
b) F2 offspring.
c) true-breeding offspring.
d) parental generation.
e) parental generation and the F1 offspring.

Answer 4

d) parental generation.

Question 5

Individuals that are heterozygous for a particular trait have

a) two different alleles of the gene
b) multiple copies of the gene
c) two identical copies of the gene
d) two different genes responsible for the trait
e) two identical alleles of the gene

Answer 5

a) two different alleles of the gene

Question 6

In pea plants, the smooth seed allele is dominant to the wrinkled seed allele. The F1 generation resulting from a mating between a true-breeding pea plant bearing smooth seeds and one bearing wrinkled seeds would show which phenotype?

a) ½ smooth seeds and ½ wrinkled seeds
b) all smooth seeds
c) all wrinkled seeds
d) ¾ wrinkled and ¼ smooth
e) ¼ wrinkled and ¾ smooth

Answer 6

b) all smooth seeds

Question 7

The offspring of two phenotyically normal people who are heterozygotes for albinism would be expected to exhibit which phenotypic ratio of normal to affected individuals?

a) 3:1
b) 1:1
c) 1:2:1
d) 1:3
e) 4:0

Answer 7

a) 3:1

Question 8

In lilies, white flowers (W) are dominant to purple flowers (w). If two plants that are heterozygous for flower color are mated, an offspring could have which phenotype?

a) white flowers
b) purple flowers
c) white flowers with purple spots
d) both A and B

Answer 8

d) both A and B

Question 9

In mice a black (Bb) female is crossed to a brown (bb) male. What proportion of the baby mice will be brown?

a) None
b) All
c) ¼
d) ½
e) ¾

Answer 9

d) ½

Question 10

In humans, brown eye color (B) is dominant to blue eyes (b). Two parents with brown eyes have a large family of 24 children. 18 of the children have brown eyes, and 6 of them have blue eyes. This indicates that the parents’ genotypes are

a) BB and bb
b) Bb and bb
c) BB and Bb
d) Bb and Bb
e) bb and bb

Answer 10

d) Bb and Bb

Question 11

In a dihybrid cross between two heterozygous pea plants (Ss Yy) that both produce smooth, yellow seeds, the gametic types produced by either parent will be

a) SY, Sy, sY, sy
b) SS, ss, YY, yy
c) S Y, S Y, s y, s y
d) Ss, Yy, Ss, Yy
e) None of the above

Answer 11

a) SY, Sy, sY, sy

Question 12

In squash, white (W) is dominant over yellow (w), disk-shaped (D) is dominant over sphere-shaped (d). Give the phenotypes of the offspring of this mating:
WW, dd X ww, DD

a) all white, disk
b) all yellow, disk
c) all white, sphere
d) all yellow, sphere
e) ½ yellow, sphere; ½ white, disk

Answer 12

a) all white, disk

Question 13

In squash, white (W) is dominant over yellow (w), disk-shaped (D) is dominant over sphere-shaped (d). Which mating will produce offspring in the ratio of 9:3:3:1?

a) WW, Dd X WW, DD
b) Ww, DD X Ww, dd
c) Ww, dd X Ww, DD
d) Ww, dd X ww, DD
e) Ww, Dd X Ww, Dd

Answer 13

e) Ww, Dd X Ww, Dd

Question 14

In squash, white (W) is dominant over yellow (w), disk shaped (D) is dominant over sphere-shaped (d). Give the phenotypes of the offspring of this mating:
WW, Dd X ww, dd

a) all yellow, sphere
b) all yellow, disk
c) all white, sphere
d) ½ white, disk; ½ white, sphere
e) ½ yellow, sphere; ½ white, disk

Answer 14

d) ½ white, disk; ½ white, sphere

Question 15

In humans, albinism is a recessive trait characterized by a lack of pigment in the skin and eyes. An albino woman marries a man with normal skin pigmentation whose mother was an albino. What percentage of their offspring are expected to be albino?

a) 0%
b) 25%
c) 50%
d) 75%
e) 100%

Answer 15

c) 50%

Question 16

In a pea plant that is heterozygous for seed color, what proportion of gametes will carry the recessive allele?

a) ¼
b) ½
c) ¾
d) all of the gametes
e) none of the gametes

Answer 16

b) ½

Question 17

In lilies, white flowers (W) are dominant to purple flowers (w). If two plants that are heterozygous for flower color are mated, the offspring might have which genotype?

a) WW
b) Ww
c) ww
d) all of the above
e) none of the above

Answer 17

d) all of the above

Question 18

In lilies, white flowers (W) are dominant to purple flowers (w). If two plants that are heterozygous for flower color are mated, the offspring would be expected to show which phenotypic ratio of white to purple flowers?

a) 3:1
b) 1:2:1
c) 9:3:3:1
d) 1:1
e) none of the above

Answer 18

a) 3:1

Question 19

In a testcross between an individual with an unknown genotype that exhibits the dominant phenotype, and a known homozygous recessive individual, the progeny showed a 1:1 ratio of dominant to recessive phenotypes. The individual of unknown genotype is therefore ____________ for that gene.

a) hemizygous
b) homogeneous
c) homozygous
d) heterozygous

Answer 19

d) heterozygous

Question 20

True breeding individuals with two identical alleles of a particular gene are _______________ for that gene

a) heterozygous
b) hemizygous
c) homozygous
d) heterogenous
e) homogenous

Answer 20

c) homozygous

Question 21

The observable characteristics of an organism that result from the expression of genes is the organism’s

a) phenotype.
b) karyotype.
c) genotype.
d) heterotype.
e) phenocopy.

Answer 21

a) phenotype.

Question 22

In a plant in which 2n = 24, what is the total number of chromatids present during prophase I of meiosis?

a) 6
b) 12
c) 24
d) 48
e) 96

Answer 22

d) 48

Question 23

Individuals that are heterozygous for a particular trait have

a) two different alleles of the gene
b) multiple copies of the gene
c) two identical copies of the gene
d) two different genes responsible for the trait
e) two identical alleles of the gene

Answer 23

a) two different alleles of the gene

Question 24

In breeding experiments, the offspring of a mating between members of the parental generation is called the _________________ generation

a) P
b) F
c) F1
d) F2
e) M

Answer 24

c) F1

Question 25

Which of the following is true concerning the inheritance of a dominant trait?

a) Every affected person must have one affected parent.
b) The trait is observed in every generation.
c) An affected heterozygote will transmit the allele to half of his or her offspring
d) All of the above
e) None of the above

Answer 25

d) All of the above

Question 26

In squash, white (W) is dominant over yellow (w), disk-shaped (D) is dominant over sphere-shaped (d). Give the phenotypes of the offspring of this mating:
Ww, Dd X ww, dd

a) ¼ yellow, sphere; ¼ yellow, disk; ¼ white, sphere; ¼ white, disk
b) all white, sphere
c) ½ white, disk; ½ white, sphere
d) ½ yellow, sphere; ½ white, disk
e) all white, disk

Answer 26

a) ¼ yellow, sphere; ¼ yellow, disk; ¼ white, sphere; ¼ white, disk

Question 27

What proportion of pea plants will produce smooth, yellow seeds (S- Y-) in the F2 generation when two F1 plants, both with the genotype Ss Yy, are crossed?

a) 3/4
b) 9/16
c) 3/16
d) 1/4
e) 1/16

Answer 27

b) 9/16

Question 28

Consider the imaginary autosomal recessive trait “hairy kneecap” (hk). You can not see the knees of a man; both his parents have normal knees, and his brother has hairy knees, what can we say about the man.

a) he could be a carrier, non-carrier, or have hairy knees
b) he must be either a carrier or have hairy knees
c) he must be either a carrier or a non-carrier with normal knees
d) he must be a carrier with normal knees
e) he must have hairy knees

Answer 28

a) he could be a carrier, non-carrier, or have hairy knees

Question 29

Assume that in rats, grey fur (T) is dominant to tan (t). If you mate a tan rat with a homozygous dominant rat, what fraction of the offspring will be HOMOZYGOUS?

a) 0
b) ¼
c) ½
d) ¾
e) all

Answer 29

a) 0

Question 30

Assume that in rats, grey fur (T) is dominant to tan (t). If you mate a tan rat with a homozygous dominant rat, what fraction of the offspring will be HETEROZYGOUS?

a) 0
b) ¼
c) ½
d) ¾
e) all

Answer 30

e) all

Question 31

Assume that you find a grey male mouse, and two grey female mice. When you mate the male to one grey female, all the offspring are grey. When you mate the male to the other grey female, ¾ of the offspring are grey, ¼ are tan. Which statement fits this data best?

a) tan is dominant, the male is homozygous
b) tan is recessive, the male is homozygous
c) tan is dominant, the male is heterozygous
d) tan is recessive, the male is heterozygous

Answer 31

d) tan is recessive, the male is heterozygous

Question 32

Which of the following is a characteristic of recessive inheritance of a relatively rare trait?

a) most affected individuals have two normal, heterozygous parents
b) matings between two normal heterozygotes should produce an approximately 3:1 ratio of normal progeny to progeny exhibiting the recessive trait.
c) when both parents are affected, they are homozygous for the recessive trait and all their progeny will usually exhibit the trait
d) all of the above
e) none of the above

Answer 32

d) all of the above

Question 33

In squash, white (W) is dominant over yellow (w), disk-shaped (D) is dominant over sphere-shaped (d). Give the phenotypes of the offspring of this mating:
Ww, Dd X Ww, Dd

a) all white, disk
b) ¼ yellow, sphere; ¼ yellow, disk; ¼ white, sphere; ¼ white, disk
c) 9/16 white, disk; 3/16 white, sphere; 3/16 yellow, disk; 1/16 yellow, sphere
d) ½ white disk; ½ white sphere
e) ½ yellow, sphere; ½ white, disk

Answer 33

c) 9/16 white, disk; 3/16 white, sphere; 3/16 yellow, disk; 1/16 yellow, sphere

Question 34

In humans, recessive traits are expressed in

a) females only.
b) every generation.
c) a person with one recessive allele.
d) a person with two recessive alleles.
e) both A and C

Answer 34

d) a person with two recessive alleles.

Question 35

A process that occurs in meiosis but not mitosis is

a) Pairing of homologs
b) Chromatid formation
c) Cell division
d) Separation of homologous centromeres to opposite poles
e) Chromosome condensation (shortening)

Answer 35

a) Pairing of homologs

Question 36

In squash, white (W) is dominant over yellow (w), disk-shaped (D) is dominant over sphere-shaped (d). Give the phenotypes of the offspring of this mating:
Ww, dd X ww, Dd

a) all white, disk
b) ¼ yellow, sphere; ¼ yellow, disk; ¼ white, sphere; ¼ white, disk
c) all white, sphere
d) ½ white, disk; ½ white, sphere
e) ½ yellow, sphere; ½ white, disk

Answer 36

b) ¼ yellow, sphere; ¼ yellow, disk; ¼ white, sphere; ¼ white, disk

Question 37

Consider the imaginary autosomal recessive trait, hairy kneecap (hk). A man has “hairy knees”. His mother does not. He has never seen his father, from the data given, what can we say about the father?

a) he could be a carrier, non-carrier, or have hairy knees
b) he must be either a carrier or have hairy knees
c) he must be either a carrier or a non-carrier with normal knees
d) he must to be a carrier with normal knees
e) he must have hairy knees