Question 1

Height, weight, and eye color are examples of phenotypes that illustrate all BUT

Accepted Answer

A) polygenic inheritance. 
B) continuous variation. 
C) pleiotropy. 
D) the action of several gene pairs each with additive effects. 
E) the cumulative effect of several gene products acting to determine phenotype.

Question 2

A cross between a rose comb chicken (RRpp) and a pea comb chicken (rrPP) produces all walnut comb chickens (RrPp).This outcome is a result of

Accepted Answer

A) environmental factors. 
B) two interacting gene pairs affecting one trait. 
C) a gene mutation in the rose comb chicken. 
D) pleiotropic effects of the P gene product. 
E) continuous variation in phenotypes.

Question 3

The type of inheritance that suggests the concept of blending is

Accepted Answer

A) multiple alleles. 
B) autosomal dominance. 
C) codominance. 
D) incomplete dominance. 
E) codominance and incomplete dominance.

Question 4

Which of the following is NOT a known effect in the expression of Marfan syndrome?

Accepted Answer

A) lanky body type 
B) weakened blood vessels 
C) lack of elasticity in the aorta 
D) excessive absorption of oxygen causing the blood cells to swell 
E) loose joints

Question 5

Mendel found that pea plants expressing a recessive trait

Accepted Answer

A) were pure-breeding. 
B) appeared only in the first generation of a cross between two pure-breeding plants expressing contrasting forms of a trait. 
C) disappeared after the second generation. 
D) could be produced only if one of the parents expressed the recessive trait. 
E) were none of these.

Question 6

A testcross involves

Accepted Answer

A) two F1 hybrids. 
B) an F1 hybrid and an F2 offspring. 
C) two parental organisms. 
D) an F1 hybrid and the homozygous dominant parent. 
E) an organism of dominant phenotype but unknown genotype and an organism that is homozygous recessive for that trait.

Question 7

The usual F2 phenotypic ratio of a dihybrid cross is

Accepted Answer

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

Question 8

The ABO blood types have __________ different genotypes.

Accepted Answer

A) 4 
B) 6 
C) 8 
D) 12 
E) 16

Question 9

Which of the following statements about Mendel is false?

Accepted Answer

A) He did not know about chromosomes. 
B) He was not aware of Darwin's theory of evolution. 
C) He was well trained in agriculture and mathematics. 
D) His work was widely recognized.. 
E) His work established a basic understanding of the principles of heredity.

Question 10

In his experiments with pea plants, Mendel removed which part of the plant to prevent unwanted fertilizations?

Accepted Answer

A) flowers 
B) petals 
C) pistils 
D) stamens 
E) stigmas

Question 11

For monohybrid experiments, a testcross can result in which of the following ratios?

Accepted Answer

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

Question 12

Which of the following descriptions of Mendel is INCORRECT?

Accepted Answer

A) He was simply lucky to work out the laws of genetics. 
B) He focused on contrasting phenotypic characteristics. 
C) He demonstrated that the blending theory of inheritance was wrong. 
D) He kept exact mathematical data and was one of the first scientists to analyze results numerically. 
E) He was a monk, a science teacher, and a plant breeder.

Question 13

The reason for the darker fur on the tail, ears, nose, and legs of a Siamese cat is

Accepted Answer

A) incomplete dominance. 
B) the activity of a heat-sensitive enzyme involved in melanin production. 
C) quantitative inheritance. 
D) epistasis. 
E) the presence of different alleles for fur color in these regions.

Question 14

In cocker spaniels, black coat color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s).If two dihybrids (Bb Ss) are crossed, the most common phenotype will be

Accepted Answer

A) black and solid. 
B) black and spotted. 
C) red and solid. 
D) red and spotted. 
E) none of these.

Question 15

A gene locus is

Accepted Answer

A) a recessive gene. 
B) an unmatched allele. 
C) a sex chromosome. 
D) the location of an allele on a chromosome. 
E) a dominant gene.

Question 16

Roan cattle are the heterozygous hybrids of a cross between a white individual and a red individual.If a roan bull were crossed with a red cow, their offspring would show which of the following ratios?

Accepted Answer

A) all roan 
B) 1 red: 2 roan: 1 white 
C) 1 red: 1 white 
D) 1 red: 1 roan 
E) all red

Question 17

Hybrid organisms produced from a cross between two pure-breeding organisms belong to which generation?

Accepted Answer

A) P1 
B) G1 
C) A1  
D) F1 
E) F2

Question 18

A bell-shaped curve of phenotypic variation is indicative of

Accepted Answer

A) incomplete dominance. 
B) continuous variation. 
C) multiple alleles. 
D) epistasis. 
E) environmental variables on phenotypes.

Question 19

Mendel's dihybrid crosses provided indirect evidence for all but which one of the following?

Accepted Answer

A) independent assortment 
B) dominance 
C) linkage 
D) presence of two factors in parents and offspring 
E) segregation of factors

Question 20

An individual with a genetic makeup of aa BB is called

Accepted Answer

A) pure-breeding. 
B) recessive. 
C) hybrid. 
D) dihybrid. 
E) heterozygous.

Exam 11: Observing Patterns in Inherited Traits