Question 1

Which of the following best explains why offspring produced by sexual reproduction are genetically different from their parents and from each other?

Accepted Answer

Because independent assortment, crossing over, and random fertilization shuffle alleles during sexual reproduction.

Question 2

A human cell containing 22 autosomes and an X chromosome could be:

Accepted Answer

A sperm cell.

Question 3

During which phase of meiosis do homologous chromosomes separate, reducing the chromosome number by half?

Accepted Answer

Anaphase I

Question 4

If an organism has a diploid number of $$2n = 12$$, how many possible combinations of chromosomes can be produced in its gametes due to independent assortment alone?

Accepted Answer

$$2^{6} = 64$

Question 5

Which of the following events occurs only during prophase I of meiosis and not during mitosis?

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 6

A plant species has a life cycle that includes both multicellular diploid and multicellular haploid stages. This is an example of:

Accepted Answer

Alternation of generations

Question 7

Which of the following statements about meiosis is FALSE?

Accepted Answer

Crossing over occurs during prophase II.

Question 8

In humans, how many chromosomes are present in a cell at the end of meiosis II?

Accepted Answer

23

Question 9

Which process is responsible for the formation of recombinant chromosomes?

Accepted Answer

Crossing over

Question 10

A geneticist observes that a certain fungus has only a single-celled diploid stage, with the multicellular organism being haploid. Which sexual life cycle does this fungus exhibit?

Accepted Answer

Zygotic meiosis

Question 11

Which of the following best describes the difference between homologous chromosomes and sister chromatids?

Accepted Answer

Sister chromatids are identical copies formed by DNA replication; homologous chromosomes are similar but not identical, each inherited from a different parent.

Question 12

Which of the following mechanisms does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during S phase

Question 13

A mutation occurs in a gene located on an autosome. Which of the following is true regarding the inheritance of this mutation?

Accepted Answer

It can be passed to offspring through gametes.

Question 14

Which of the following equations correctly represents the number of possible chromosome combinations due to independent assortment in a species with a haploid number $$n$$?

Accepted Answer

$$2^n$$

Question 15

Which of the following is a direct result of the process of crossing over during meiosis?

Accepted Answer

The formation of recombinant chromosomes

Question 16

A researcher observes a cell with chromosomes aligned in pairs at the metaphase plate, with microtubules attached to kinetochores of homologous chromosomes. Which stage is this cell in?

Accepted Answer

Metaphase I of meiosis

Question 17

Which of the following statements about the evolutionary significance of sexual reproduction is correct?

Accepted Answer

Sexual reproduction allows for the accumulation of genetic variations favored by natural selection.

Question 18

Which of the following best explains why only diploid cells can undergo meiosis?

Accepted Answer

Because only diploid cells have homologous pairs of chromosomes that can be separated.

Question 19

If a human zygote undergoes mitosis, what will be the chromosome number in each resulting cell?

Accepted Answer

46

Question 20

Which of the following is NOT a difference between mitosis and meiosis?

Accepted Answer

Sister chromatids separate during mitosis but not during meiosis.

Meiosis and Sexual Life Cycles: Mechanisms of Inheritance and Genetic Variation

Study Guide - Practice Questions

Study Guide - Flashcards