Chapter 14 - Mendel and the Gene Idea

Question 1

Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes?

Answer 1

100%

Question 2

The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates what?

Answer 2

All of the genes controlling the traits behaved as if they were on different chromosomes

Question 3

In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?

Answer 3

0

Question 4

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

Answer 4

Traits are inherited in discrete units, and are not the results of “blending.”

Question 5

Map units on a linkage map cannot be relied upon to calculate physical distances on a chromosome for which of the following reasons?

Answer 5

The frequency of crossing over varies along the length of the chromosome

Question 6

Feather colour in budgies is determined by two different genes, Y and B, one for pigment on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white.

Two blue budgies were crossed. Over the years, they produced 22 offspring, 5 of which were white. What are the most likely genotypes for the two blue budgies?

Answer 6

yyBb and yyBb

Question 7

A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A woman with normal vision whose father is color blind marries a color-blind male. What is the probability that this couple’s first son will be color blind?

Answer 7

1/2

Question 8

A man who carries an allele of an X-linked gene will pass it on to whom?

Answer 8

all of his daughters