Deck 12: Patterns of Inheritance

Question 1

The Principle of ________ states that the 2 alleles present at each gene locus separate from one another during gamete formation and remain distinct.

A)Alleles
B)Segregation
C)Crossing over
D)Dominance

Answer 1

B

Question 2

In Mendel's experiments on seed color in pea plants, when a dominant yellow seed-bearing plant was crossed with a recessive green seed-bearing plant, what was the approximate phenotypic ratio among the F₂ generation?

A)1 yellow: 3 green
B)1 yellow: 1 green
C)3 yellow: 1 green
D)all yellow

Answer 2

C

Question 3

What type of cross is used to determine if an individual with the dominant form of a trait is homozygous or heterozygous?

A)double cross
B)dihybrid cross
C)reciprocal cross
D)test cross

Answer 3

D

Question 4

In modern terminology, Mendel's heredity "factors" are called

A)DNA.
B)chromosomes.
C)genes.
D)RNA.

Question 5

Let P = purple flowers and p = white, and T = tall plants and t = dwarf.If the upper case letters represent the dominant alleles, what is the phenotype of a plant with the genotype PpTt?

A)purple flowers, tall
B)purple flowers, dwarf
C)white flowers, tall
D)white flowers, dwarf

Question 6

If fertilization involves two gametes that contain different alleles of a given gene, the resulting offspring is

A)dihybrid.
B)haploid.
C)heterozygous.
D)homozygous.

Question 7

In a heterozygous individual, the allele being expressed is

A)recessive.
B)codominant.
C)pleiotropic.
D)dominant.

Question 8

Mendel used the ______ to determine whether an individual with the dominant phenotype was homozygous or heterozygous for that trait.

A)backcross
B)testcross
C)dihybrid cross
D) F₂ generation

Question 9

The allelic make up of a cell or individual is referred to as its

A)blueprint.
B)genotype.
C)phenotype.
D)pedigree.

Question 10

Mendel used the garden ___ plant for his studies on inheritance.

A)lily
B)carrot
C)onion
D)pea

Question 11

The observable expression of the genes present in an organism is called its

A)phenotype.
B)genotype.
C)pedigree.
D)karyotype.

Question 12

A cross where we follow the inheritance of 2 pairs of alleles is called

A)homozygous.
B)monohybrid.
C)dihybrid.
D)heterozygous.

Question 13

A diploid organism that has two identical alleles for a given trait is called _______ for that trait.

A)homozygous
B)heterozygous
C)dominant
D)recessive

Question 14

The first detailed and quantitative studies on inheritance were carried out by an Austrian monk named _____.

A)Mendel
B)Darwin
C)Mendeleev
D)Benedict

Question 15

The phenotypic ratio for the F₁ generation that results from a testcross between a homozygous individual and a heterozygous individual is

A)1:1
B)2:1
C)3:1
D)1:2:1

Question 16

An allele for a particular trait that is only expressed in the presence of a second copy of the same allele is called

A)dominant.
B)codominant.
C)incompletely dominant.
D)recessive.

Question 17

Alternate forms of the same gene are called

A)homologues.
B)genotypes.
C)cofactors.
D)alleles.

Question 18

The observable outward manifestation of the genes of an individual is referred to as its

A)blueprint.
B)genotype.
C)phenotype.
D)genetic map.

Question 19

During his experiments with pea plants, Mendel referred to the trait that was expressed in the F₁ or first filial generation as

A)recessive.
B)dominant.
C)codominant.
D)independent.

Question 20

Individuals that have 2 alleles for most gene loci are best described as

A)haploid.
B)diploid.
C)dihybrid.
D)homozygous.

Question 21

An extensive study was conducted on identical twins who were separated at birth.Among other things, the study showed that the individual from each pair who received better nutrition during childhood tended to score higher on standardized intelligence tests.This can best be described as an example of how

A)mutation alters phenotype.
B)environment alters phenotype.
C)environment alters genotype.
D)mutation alters genotype.

Question 22

A person who has lost a large amount of blood but is still alive is found in a wrecked automobile under a highway bridge.Several people are helping the paramedics load the victim into the ambulance.After the ambulance has departed for the hospital, you overhear the following conversation from the persons who helped the paramedics."I am certain that when that guy gets to the hospital, they will transfuse him with any blood that they have in the blood bank since he has lost so much blood." The other person says, "Yeah, I bet you're right!" Having had a biology course, you know which blood could be safely given to anyone.Select it below.

A)A
B)B
C)AB
D)O

Question 23

A male fruit fly has the genotype PpYYrrTt.In terms of these 4 allele pairs, how many different types of gametes can he form?

A)2
B)4
C)8
D)16

Question 24

Mendel's Principle of Independent Assortment states that different pairs of

A)non-homologous chromosomes segregate independently of each other.
B)sister chromatids segregate independently of each other.
C)non-sister chromatids segregate independently of each other.
D)alleles segregate independently of each other.

Question 25

When Mendel crossed purple-flowered pea plants with white-flowered pea plants, he never got offspring with flowers that had an intermediate color.This was counter to the theory of

A)independent assortment.
B)blending inheritance.
C)direct transmission of traits.
D)segregation of alleles.

Question 26

The genotypic ratio produced in the last cross is most likely

A)3:1
B)1:2:1
C)2:1
D)9:3:3:1

Question 27

Height is a trait that shows continuous variation in humans.In pea plants, on the other hand, the tall allele is dominant over the short allele and there are no intermediate heights.What is the best explanation for this difference?

A)The alleles that control height in pea plants are epistatic.
B)The alleles that control height in pea plants are pleiotropic.
C)The alleles that control height in humans are pleiotropic.
D)Height is a polygenic trait in humans.

Question 28

A diploid individual carrying two identical alleles at a given gene locus is called

A)homologous.
B)heterozygous.
C)homozygous.
D)dihybrid.

Question 29

If you crossed flies heterozygous for the Cy allele, what phenotypes would you find in the adult F₁ generation?

A)both wild type and curly wings
B)wild type only
C)curly wings only
D)None because all the F₁ flies would die before reaching adulthood.

Question 30

ABO blood group determination is an example of

A)epistasis.
B)incomplete dominance.
C)polygenic inheritance.
D)multiple alleles.

Question 31

Sometimes, when Mendel crossed two pea plants with each other, he obtained a phenotypic ratio of 3:1 purple-flowered pea plants to white-flowered pea plants.These results are consistent with which set of parents?

A)homozygous purple pea plant and homozygous white pea plant
B)heterozygous purple pea plant and homozygous white pea plant
C)heterozygous purple pea plant and homozygous purple pea plant
D)heterozygous purple pea plant and heterozygous purple pea plant

Question 32

A diploid individual carrying two different alleles at a given gene locus is called

A)homologous.
B)heterozygous.
C)homozygous.
D)polygenic.

Question 33

Let P = purple flowers and p = white, and T = tall plants and t = dwarf.What are the genotypes of the gametes that are produced by a plant that is heterozygous for both traits?

A)PpTt only
B)PT and pt
C)P, p, T, and t
D)PT, Pt, pT, and pt

Question 34

If an individual allele has more than one effect on the phenotype, this is called

A)pleiotropy.
B)epistasis.
C)blending inheritance.
D)multiple alleles.

Question 35

The observable expression of the genes present is called

A)genotype
B)karyotype
C)epistasis
D)phenotype

Question 36

Let P = purple flowers and p = white, and T = tall plants and t = dwarf.Of the 16 possible gamete combinations in the dihybrid cross between 2 double heterozygotes, how many would produce the phenotype white, tall?

A)none
B)1
C)3
D)9

Question 37

The ______ of an organism refers to the alleles that are present.

A)genotype
B)karyotype
C)pedigree
D)phenotype

Question 38

The most-likely explanation for this inheritance pattern is that the secretor trait is

A)incompletely dominant.
B)recessive.
C)dominant.
D)co-dominant.

Question 39

If a single gene has 3 or more alternative forms, this is called

A)pleiotropy.
B)multiple alleles.
C)epistasis.
D)blending inheritance.

Question 40

In white tigers, the absence of fur pigmentation is caused by a recessive allele that also causes the tigers to be cross-eyed.If two tigers heterozygous for this allele mate, what do you expect to see among the offspring?

A)1/4 will be both white and cross-eyed, 3/4 will be orange with normal eyes.
B)1/4 will be white with normal eyes, 1/4 will be white and cross-eyed, 1/4 will be orange with normal eyes, and 1/4 will be orange and cross-eyed.
C)1/16 will be white and cross-eyed, 15/16 will be orange with normal eyes.
D)1/3 will be both white and cross-eyed, 2/3 will be orange with normal eyes.

Question 41

Achondroplasia is a common form of dwarfism caused by an autosomal dominant mutation in the fibroblast growth factor receptor 3 (FGFR3) gene.Two copies of the mutant gene are invariably fatal before or shortly after birth.If a person with achondroplasia marries a person of normal height, what is the probability that both their first child and second child will have achondroplasia?

A)1/8
B)1/4
C)1/2
D)1

Question 42

In rabbits, there is a gene that controls ear length, with a dominant allele "T" for long ears and a recessive allele "t" for short ears.At another gene locus, there are alleles "B" for black coat and "W" for white coat.Neither the B or W allele is dominant, and BW produces a gray coat.These two allele pairs assort independently.If a gray rabbit that is heterozygous at the gene locus controlling ear length is mated with a white rabbit that is also heterozygous at the gene locus controlling ear length, what is the probability that their first offspring will be gray with long ears?

A)1/16
B)3/16
C)1/8
D)3/8

Question 43

Mendel performed reciprocal crosses in which he used pollen from a white-flowered plant to fertilize a purple-flowered plant and pollen from a purple-flowered plant to fertilize a white-flowered plant.What did these reciprocal crosses demonstrate?

A)The female gamete made a larger genetic contribution to the offspring than the male gamete.
B)Each parent made an equal genetic contribution to the offspring.
C)Flower color is a sex-linked trait.
D)The traits of flower color and sex assort independently.

Question 44

You toss a coin twice.Because the outcome of the first toss does not affect the outcome of the second toss, these 2 events are called

A)mutually exclusive.
B)independent.
C)dependent.
D)random.

Question 45

A Punnett square is generally used to

A)determine the genotype of each parent from its phenotype.
B)determine the phenotype of each parent from its genotype.
C)predict the genotypic ratio among the offspring.
D)predict the number of offspring that will exhibit each genotype.

Question 46

Let Y = yellow and y = green, and R = round and r = wrinkled.You cross YYRR peas with yyrr peas.All of the F₁ individuals are yellow and round with a genotype of YyRr.You then perform an F₂ cross and get the expected 9:3:3:1 phenotypic ratio.What proportion of the F₂ plants are expected to be heterozygous for both traits?

A)1/16
B)1/4
C)1/2
D)9/16

Question 47

As a genetic counselor, you are constructing a human pedigree for a particular disease.You note that every generation shows the trait, suggesting that the trait is

A)sex-linked.
B)recessive.
C)dominant.
D)polygenic.

Question 48

Let R = red pigment and r = no pigment.In carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring make a small amount of red pigment, thus appearing pink.Pink carnations are therefore an example of

A)codominance.
B)incomplete dominance.
C)epistasis.
D)pleiotropy.

Question 49

Three babies were recently mixed up in a hospital.Based on the data in the table above, the couple with blood types A and B are the actual parents of the child with blood type

A)O
B)B
C)AB
D)none of these babies could be the child of the couple with blood types A and B

Question 50

If you are tossing a six-sided die, what is the probability of getting either a 1 or a 2 on your first toss AND a 1 or a 2 on your second toss?

A)1/18
B)1/9
C)1/6
D)1/3

Question 51

what proportion of the long-eared offspring will be homozygous for the long-eared allele?

A)1/8
B)1/4
C)1/3
D)1/2

Question 52

In humans, the sickle-cell trait is caused by a single defective allele, but sickle-cell disease only occurs in individuals that are homozygous for the sickle-cell allele.A man and woman each carry the trait, but do not have sickle-cell disease.What is the probability that their first two children will both have sickle-cell disease?

A)1/16
B)1/8
C)1/4
D)3/8