all Vgvg and all normal wings.
3 Vgvg: 1 vgvg and 3 normal: 1 vestigial.
1 Vgvg: 1 vgvg and 1 normal: 1 vestigial.
3 vgvg: 1 Vgvg and 3 vestigial: 1 normal.
The ratios cannot be determined from the data given.

Question #2
In crossing a homozygous recessive with a heterozygote, the chance of getting a recessive phenotype in the next generation is:

25 percent.
50 percent.
75 percent.
100 percent.
0 percent

Question #3
A couple has three children, all of whom have blond hair and brown eyes. Both parents have brown eyes (BB), but one is a blond (Rr) and the other is a redhead (rr). What is the probability that the next child will be a brown-eyed redhead?

1/16
1/8
1/4
1/2
1

 Question #4
Pea flowers may be purple (W) or white (w). Pea seeds may be round (R) or wrinkled (r). What proportion of the progeny from the cross WwRr x WwRr will have white flowers and wrinkled seeds?

1/16
3/16
8/16
9/16
all of them

Question #5
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What proportion of the progeny of the cross BbTt x Bbtt will have black fur and long tails?

1/16
3/16
6/16
8/16
9/16

Question #6
Self-pollination in a plant that is heterozygous for two independently assorting genes will produce ________ phenotypes among the progeny.

one
two
three
four
eight

Question #7
How many different kinds of gametes may be produced by an organism with the genotype rRYY?

one
two
three
four
five

Question #8
How many different kinds of gametes may be produced by an organism with the genotype RrYy?

one
two
three
four
five

 Question #9
In peas, round seed shape (R) is dominant to wrinkled shape (r) and yellow seed color (Y) is dominant to green (y). If two plants of genotype RrYy are crossed, what proportion of the offspring would have round, yellow seeds?

3/4
9/16
3/16
1/4
1/16

3/4
9/16
3/16
1/4
1/16

Question #11
If two parents are doubly heterozygous (e.g., AaBb x AaBb) for genes governing different traits, what proportion of the offspring would exhibit both dominant traits?

3/4
9/16
3/16
1/4
1/16

Question #12
In pea flowers, purple color (W) is dominant to white (w). When a heterozygous purple-flowered pea plant is crossed with a white-flowered pea plant the offspring are:

all white.
all purple.
half white and half purple.
three purple and one white
fourth purple.

Question #13
The ultimate source of variation within a population upon which natural selection can operate is:

mutation.
recombination.
independent assortment.
segregation.
environmental influences.

Question #14
Consider a cross between two organisms both of which are heterozygous for both of two independently assorting allele pairs. What is the probable phenotypic ratio of their offspring?

1:1
3:1
1:4:6:4:1
1:2:1:2:4:2:1:2:1
9:3:3:1

Question #15
For a cross between a male and female that are both heterozygous for two pairs of alleles, a Punnett square will indicate that the offspring could be any one of.................. different genotypes.

16
9
7
4
3

Question #16
An organism that consistently produces offspring that resemble itself with respect to a particular trait or traits is:

true breeding
heterozygous for the trait(s).
self fertilizing
not engaging in independent assortment.
genetically impossible.
pollinating itself

Question #17
Parents heterozygous for two genes can produce progeny that are different in phenotype and genotype from themselves. This illustrates:

a testcross for two traits.
the effects of crossbreeding.
that dominance produces increased variability.
the principle of independent assortment.
that recessive alleles can be expressed in the heterozygous state.

Question #18
Which of these exemplifies a testcross?

AA x Aa
Aa x Aa
aa x aa
Aa x aa
Both a and d are testcrosses.

RRYy
RrYY
RRYY
RRyy
RrYy

Question #20
The cross between a homozygous recessive individual and one of dominant phenotype, but whose genotype is unknown, is called a:

cross-pollination.
testcross.
heterozygous cross.
backcross.
determination cross.

Question #21
The genetic composition of an organism is known as its:

gene pool.
trait or characteristic.
allele.
genotype.
phenotype.

Question #22
An organism with two identical alleles for a given trait is:

homozygous.
segregating.
dominant.
unusually rare.
a hermaphrodite.

Question #23
A recessive allele is one that:

is not present as often as a dominant allele.
is expressed only in a homozygote.
cannot be inherited from a heterozygote.
depends upon a dominant partner for expression.
can only be inherited from a homozygous parent.

Question #24
When a true-breeding pea plant that has yellow seeds is pollinated by a plant that has green seeds, all of the F1 plants have yellow seeds. This means that the allele for yellow is:

homozygous.
dominant.
true breeding
present in both parents.
assorting independently.

produces identical offspring.
allows for less crossing over.
requires only one nuclear division.
requires a great expenditure of energy.
provides genetic variation in the offspring.

3:1; red to one white
3:1; white to red
1:1:1:1; red males, white males, red females, white females
1:1 red eyed males to white eye females
1:1 white eyed males to red eyed females

Question #27
When Morgan crossed a homozygous red-eyed female Drosophila with a white-eyed male, what (approximate) phenotypic ratio occurred in the offspring?

3:1; red to white
3:1; white to red
1:1:1:1; red males, white males, red females, white females
1:1 red to white males and females
all red eyed males and females

Question #28
When Morgan crossed a heterozygous red-eyed female Drosophila with a white-eyed male, what (approximate) phenotypic ratio occurred in the offspring?

3:1; re
3:1; re
1:1:1:1; re
eyed males to whit
eyed males

Question #29
Morgan crossed a white-eyed male Drosophila with a red-eyed female and obtained red-eyed males and females in the F1 generation. When these were crossed, the F2 generation contained white-eyed males, but no white-eyed females. Why?

The expression of white eye color is limited to males.
The gene for white eyes is lethal in females.
The gene for white eyes is autosomal.
The gene for white eyes is on the Y chromosome.
The gene for white eyes is on the X chromosome.

dominance.
epistasis.
recessiveness.
blending inheritance.
incomplete dominance.

Question #31
A man with type A blood marries a woman with type B blood. If both parents are homozygous, their offspring will have type _____ blood, which is an example of _____.

AB; codominance
A; dominance of A over B
B; dominance of B over A
AB; incomplete dominance
O; recessiveness

Question #32
In a population expressing five different alleles for a particular gene, how many alleles may be present in each diploid organism in the population?

one
two
three
four
five

Question #33
When heterozygous pink snapdragons are allowed to self-pollinate, the red and white characteristics sort themselves out:

so that the F2 plants are all white.
so that the F2 plants are all red.
proving that alleles remain discrete and unaltered in the heterozygous state.
proving that these genes were not on the same pair of homologous chromosomes.
demonstrating that blending inheritance is fundamentally true.

Question #34
In chickens, comb shape is determined by the interaction of two genes, R and P. Phenotypes and corresponding genotypes are single (rrpp), rose (R-pp), pea (rrP-), and walnut (R-P-). (A blank indicates either the dominant or the recessive allele.) If a hen and a rooster, both of which are heterozygous for both genes, are mated, the offspring will have _________ combs in a ratio of _________ .

only rose and pea; 1:1
walnut, rose, and pea; 1:1:1
walnut, rose, pea, and single; 1:1:1:1
walnut, rose, pea, and single; 9:3:3:1
walnut and single; 9:7

Question #35
Flower color in sweet peas is determined by the epistatic interaction of two genes, C and P. The genotypes CCpp and ccPP both produce white flowers. Purple flowers occur when one dominant allele of each gene is present. If two white flowering plants (one of each genotype) are crossed, what phenotype(s) and genotype(s) would occur in the offspring.

all white; ccpp
all purple; CCPP
purple and white; CcPp and ccpp in a 1:1 ratio
purple and white; CcPp and ccpp in a 3:1 ratio
all purple; CcPp

epistasis.
the appearance of a novel phenotype.
the effect of the environment on the expression of phenotype.
interacting homologous alleles.
the interaction between two different genes.