Q: Which formula describes the relationship between the frequency of crossing over and the distance between two genes on a chromosome?

$$\text{Recombination frequency} = \frac{\text{Number of recombinant offspring}}{\text{Total number of offspring}}$$

Question 1

Thomas Hunt Morgan's experiments with Drosophila melanogaster provided evidence for which of the following genetic principles?

Accepted Answer

Some genes are located on sex chromosomes and show sex-linked inheritance.

Question 2

In Morgan's fruit fly experiments, red eyes were considered 'wild-type' and white eyes 'mutant.' If a white-eyed female is crossed with a red-eyed male, which statement best describes the expected outcome for male offspring?

Accepted Answer

All male offspring will have white eyes.

Question 3

Which of the following best explains why reciprocal crosses for X-linked traits can yield different results?

Accepted Answer

The inheritance pattern depends on which parent contributes the X-linked allele.

Question 4

During meiosis in males, what is the expected proportion of sperm containing X chromosomes versus Y chromosomes?

Accepted Answer

50% X, 50% Y

Question 5

Which equation correctly represents the probability of a son inheriting an X-linked recessive trait from a heterozygous mother and a normal father?

Accepted Answer

$$P = 0.5$$

Question 6

If two genes are located close together on the same chromosome, what is the most likely outcome regarding their inheritance?

Accepted Answer

They will be inherited together more frequently than genes that are far apart.

Question 7

A geneticist observes that two traits in an insect (dark body and feathered wings) do not assort independently and the recombinant offspring are less frequent than parental types. What does this suggest about the genes controlling these traits?

Accepted Answer

The genes are linked and located close together on the same chromosome.

Question 8

Which formula describes the relationship between the frequency of crossing over and the distance between two genes on a chromosome?

Accepted Answer

$$	ext{Recombination frequency} = \frac{	ext{Number of recombinant offspring}}{	ext{Total number of offspring}}$$

Question 9

Which of the following is an example of incomplete dominance?

Accepted Answer

A heterozygote expresses a phenotype intermediate between both homozygotes.

Question 10

A person with Marfan syndrome exhibits multiple symptoms affecting the skeleton, eyes, and cardiovascular system. This is an example of:

Accepted Answer

Pleiotropy

Question 11

Phenylketonuria (PKU) is a genetic disorder that can be managed by dietary changes. What does this illustrate about gene expression?

Accepted Answer

Environmental factors can influence the expression of genetic traits.

Question 12

Human height is an example of a quantitative trait. Which statement best explains the inheritance of such traits?

Accepted Answer

Quantitative traits are influenced by many genes and often show a normal distribution.

Question 13

Which of the following is true about autosomal recessive inheritance?

Accepted Answer

Affected individuals are homozygous for the recessive allele.

Question 14

In a pedigree, what does a shaded square represent?

Accepted Answer

An affected male

Question 15

Which of the following human traits is most likely to be inherited in an X-linked recessive manner?

Accepted Answer

Green color blindness

Question 16

A heterozygous woman for the freckles gene (Ff) and a man without freckles (ff) have three children: one daughter with freckles, one daughter without freckles, and one son without freckles. What are the possible genotypes of the children?

Accepted Answer

Daughter with freckles: Ff; daughter without freckles: ff; son without freckles: ff.

Question 17

Which equation would you use to calculate the expected frequency of recombinant offspring between two genes that are 20 map units apart?

Accepted Answer

$$	ext{Expected frequency} = 0.20$$

Question 18

Which of the following is NOT a feature of sex-linked inheritance?

Accepted Answer

Both males and females always inherit two copies of the gene.

Question 19

Which of the following genetic disorders is caused by an autosomal dominant allele?

Accepted Answer

Huntington's disease

ch 14 pt 2

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드