CH3: Basic Principles of Hereditary

From both test attempts

wild-type; mutant

Ecologists are sampling mice from different parks in NYC. Most of the mice these researchers collect demonstrate “straight” tails; however, few mice exhibit “curly” tails.

In this scenario, a “straight” tail would be considered the () phenotype, and a “curly” tail would be considered a () phenotype.

50%

What is the likelihood that an individual who is heterozygous for the TYRP1 gene and an individual who has blond hair will have a child with blond hair?

(Both individuals are of Solomon Island descent).

1 : 1

“Dumpy” is a commonly used mutant phenotype in the nematode worm C. elegans. Two “Dumpy” individuals are crossed to each other, and this cross produces 210 “Dumpy” and 68 wild-type individuals.

If one of the “Dumpy” individuals used in this cross was mated with a wild-type, what “Dumpy”: wild-type ratio would we observe in the offspring?

1/64 (i.e., ½ X ¼ X 1/8)

A researcher is interested in genotypes in mice. He knows the following: the probability of a mouse having the genotype dd is 1/2, the probability of a mouse having the genotype tt is 1/4, and the probability of a mouse having the gg is 1/8.

Using this information, the researcher can determine that the probability of a mouse having the genotype dd tt gg is:

½

A phenotypically normal man has phenotypically normal parents, but he has a sister who has cystic fibrosis caused by a recessive mutant allele.

What is the probability that the man is heterozygous for the cystic fibrosis allele?

2/3

Suppose that a single gene controls fruit color in mango.

Yellow fruit (Y) is dominant to red fruit (y). Suppose a pure-line yellow mango plant was crossed with a red-fruited plant, and the resulting F1 was selfed. The F2 segregated as expected.

If one of the yellow-fruited plants was randomly selected and selfed, what is the probability that its progeny would segregate for fruit color (that is, show more than one fruit color in the progeny)?

True

Branched diagrams are used for determining probabilities of various phenotypes or genotypes for genetic crosses involving more than one gene pair.

True

The chi-square test is used to determine if observed outcomes are consistent with expected outcomes.

True

The probability of rolling an even number on a single roll of a six-sided die is 1/6 + 1/6 + 1/6

¼

Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b, respectively.

What is the probability of producing an AaBb zygote from a cross of AaBb X AABB?

1/16

Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b, respectively.

What is the probability of producing an AABB zygote from a cross of AaBb X AABB?

1: 1: 1: 1

If genes assort independently, a testcrossed dihybrid characteristically produces progeny phenotypes in the ratio:

1/8

A tall purple flower plant with genotype TtPp is crossed with a tall white flower plant of genotype Ttpp.

What is the probability of obtaining progeny with genotype TTpp?

27/128

Consider the following cross examining five unlinked (assorting independently) genes.

Identify what proportion of progeny will be phenotypically identical to parent 2?

Parent 1: Aa Bb Cc Dd Ee

Parent 2: AA bb Cc Dd Ee

9/64

In the cross between a female Aa Bb cc Dd ee and male Aa bb Cc Dd ee, what proportion of the progeny will be phenotypically identical to the female parent?

(Assume independent assortment of all genes and complete dominance).

16

If a plant of genotype Aa Bb Cc Dd is selfed and the genes assort independently, how many different phenotypes will be found among the progeny?

1/4 (or 25%)

Two genes T and Q in the pea plant (Pisum sativum) determine the texture and the size of the leaves, respectively.

A pure line of pea plants with genotype TTqq is crossed to a pure line with genotype ttQQ. The F1 plants are crossed to each other to generate the F2.

What proportion of the F2 plants are the result of a recombinant ovum being fertilized by a recombinant pollen? Two genes assort indepenedently.

evolution by natural selection

Which concept is NOT associated with Mendel?

It has characteristics for which the phenotypes are easy to differentiate

Why was the pea an ideal plant for Mendel to use?

testcross

An individual displays a dominant phenotype. To determine whether the individual is homozygous for the dominant allele or heterozygous at that locus, it would be best to do a: