Question 1

Which of the following best explains why Mendel's laws of inheritance could not be fully understood during his time?

Accepted Answer

Chromosomes had not yet been discovered, so the physical basis for inheritance was unknown.

Question 2

In the context of meiosis, what is the significance of the law of segregation?

Accepted Answer

It explains how alleles of a single gene separate during anaphase I.

Question 3

A pea plant with genotype $$YyRr$$ undergoes meiosis. According to the law of independent assortment, what is the expected ratio of gamete types produced?

Accepted Answer

$$1:1:1:1$$ for YR, Yr, yR, yr

Question 4

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry the same genes at the same loci but may have different alleles.

Question 5

In Morgan's experiments with Drosophila, what was the significance of the white-eyed mutant male crossed with a red-eyed female?

Accepted Answer

It demonstrated that the gene for eye color is located on the X chromosome.

Question 6

Why are X-linked recessive traits more commonly expressed in males than in females?

Accepted Answer

Males are hemizygous for the X chromosome, so a single recessive allele will be expressed.

Question 7

Which of the following best describes the outcome of a cross between a carrier female for an X-linked recessive trait and a normal male?

Accepted Answer

Half of the sons will express the trait, and half of the daughters will be carriers.

Question 8

Which sex determination system is found in birds, and what is the chromosomal composition of a female in this system?

Accepted Answer

ZW system; females are ZW

Question 9

What is the biological significance of X chromosome inactivation in female mammals?

Accepted Answer

It ensures dosage compensation so that females do not produce twice as many X-linked gene products as males.

Question 10

A tortoiseshell cat displays patches of orange and black fur. Which genetic mechanism explains this phenotype?

Accepted Answer

Random X chromosome inactivation in heterozygous females.

Question 11

If a male fruit fly inherits a mutant allele for eye color on the X chromosome, what will be his phenotype?

Accepted Answer

He will express the mutant phenotype because he has only one X chromosome.

Question 12

Which of the following is true about the Y chromosome in humans?

Accepted Answer

It contains fewer genes than the X chromosome and is primarily involved in male sex determination.

Question 13

In the haplodiploid sex determination system, such as in honeybees, what determines whether an individual is male or female?

Accepted Answer

Ploidy: diploid individuals are female, haploid individuals are male.

Question 14

Which of the following best describes the chromosomal composition of a human male's somatic cell?

Accepted Answer

$$44 + XY$$

Question 15

A female who is heterozygous for an X-linked gene will have which of the following outcomes in her somatic cells?

Accepted Answer

Some cells will express one allele, and some will express the other due to random X inactivation.

Question 16

Which of the following is a direct result of the law of independent assortment during meiosis?

Accepted Answer

Genetic variation among gametes due to random alignment of non-homologous chromosomes.

Question 17

If a male with an X-linked recessive disorder has children with a female who is a carrier, what is the probability that a daughter will be affected?

Accepted Answer

$$0.5 or$$ $$50\%$$

Question 18

Which of the following is NOT a feature of model organisms like Drosophila melanogaster for genetic studies?

Accepted Answer

They allow for the study of sex-linked inheritance.

Question 19

Which of the following best explains why males cannot be carriers for X-linked recessive traits?

Accepted Answer

Males have only one X chromosome, so any allele present will be expressed.

Question 20

Which of the following is a real-world example of an X-linked recessive trait in humans?

Accepted Answer

Red-green color blindness

Bio 100 LEC Chapter 15 Study Guide Module 1-2

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드