Chapter 13 - Observing Patterns In Inherited Traits

Question 1

A heterozygous individual has a _____________ for a trait being studied.

a. a pair of identical alleles
b. a pair of nonidentical alleles
c. haploid condition, in genetic terms

Answer 1

b. pair of nonidentical alleles

Question 2

An organisms observable traits constitute its __________.

a. phenotype
b. variation
c. genotype
d. pedigree

Answer 2

a. phenotype

Question 3

Filial means _____________.

Answer 3

offspring

Question 4

The second-generation offspring of a cross between individuals who are homozygous for different alleles of a gene are called the ______________.

a. F1 generation
b. F2 generation
c. hybrid generation
d. none of the above

Answer 4

b. F2 generation

Question 5

F1 offspring of the cross AA X aa are ________________.

a. all AA
b. all aa
c. all Aa
d. 1/2 AA and 1/2 aa

Answer 5

c. all Aa

Question 6

Assuming complete dominance, what is phenotypic ratio of the second generation of offspring of a cross between individuals who are homozygous for different alleles of a gene?

a. 3:1
b. 9:1
c. 1:2:1
d. 9:3:3:1

Answer 6

a. 3:1

Question 7

A testcross is a way to determine ____________.

a. phenotype
b. genotype
c. both a and b

Answer 7

b. genotype

Question 8

Assuming complete dominance, crosses between two dihybrid F1 pea plants, which are offspring from a cross AABB X aabb, result in F2 phenotype ratios of _________________.

a. 1:2:1
b. 3:1
c. 1:1:1:1
d. 9:3:3:1

Answer 8

d. 9:3:3:1

Question 9

The probability of a crossover occurring between two genes on the same chromosome ____________.

a. is unrelated to the distance between them
b. decreases with the distance between them
c. increases with the distance between them

Answer 9

c. increases with the distance between them

Question 10

A gene that affects three traits is ______________.

a. epistatic
b. a multiple allele system
c. pleiotropic
d. dominant

Answer 10

c. pleiotropic

Question 11

____________ alleles are both expressed.

a. Dominant
b. Codominant
c. Pleiotropic
d. Hybrid

Answer 11

b. Codominant

Question 12

A bell curve indicates ___________ in a trait.

Answer 12

continuous variation

Question 13

Match the terms with the best description.

___ dihybrid cross
___ monohybrid cross
___ homozygous condition
___ heterozygous condition

a. bb
b. AABB X aabb
c. Aa
d. Aa X Aa

Answer 13

Match the terms with the best description.

(b) dihybrid cross
(d) monohybrid cross
(a) homozygous condition
(c) heterozygous condition

a. bb
b. AABB X aabb
c. Aa
d. Aa X Aa