Question 1

Which of the following statements best explains why offspring produced by sexual reproduction are genetically unique?

Accepted Answer

Because homologous chromosomes are randomly assorted and crossing over occurs during meiosis.

Question 2

During which specific stage of meiosis does the reduction in chromosome number from diploid to haploid occur?

Accepted Answer

Anaphase I

Question 3

A certain animal species has a diploid number of $$2n = 12. $$After meiosis II is complete, how many chromosomes will each gamete contain?

Accepted Answer

$$6$$

Question 4

Which of the following events occurs during Prophase I of meiosis but not during mitosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 5

If a human cell undergoes meiosis, how many genetically distinct gametes are produced at the end, and what is their chromosome number?

Accepted Answer

Four gametes, each with $$n = 23$$ chromosomes

Question 6

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

Accepted Answer

Homologous chromosomes are similar but not identical, while sister chromatids are exact copies of each other.

Question 7

A plant cell with $$2n = 8$$ undergoes meiosis. After Telophase I and cytokinesis, what is the chromosome number in each resulting cell, and what is the state of the chromatids?

Accepted Answer

Each cell has $$n = 4$$ chromosomes, each consisting of two sister chromatids.

Question 8

Which of the following is a key difference between meiosis in animals and plants?

Accepted Answer

In animals, meiosis directly produces gametes, while in plants, meiosis produces spores that develop into gametophytes.

Question 9

Which of the following best explains why asexual reproduction results in offspring that are genetically identical to the parent?

Accepted Answer

Because the offspring inherit all their DNA from a single parent without recombination.

Question 10

During which stage of meiosis do sister chromatids finally separate and move to opposite poles?

Accepted Answer

Anaphase II

Question 11

A geneticist is studying a species of crab with $$2n = 208$$ chromosomes. After meiosis II, how many chromosomes will be present in each gamete?

Accepted Answer

$$104$$

Question 12

Which of the following processes increases genetic variation during meiosis?

Accepted Answer

Crossing over during Prophase I

Question 13

If a mosquito has $$2n = 6$$ chromosomes, how many different combinations of maternal and paternal chromosomes are possible in its gametes, ignoring crossing over? (Use the formula $$2^n$$ where $$n is $$the haploid number.)

Accepted Answer

$$8$$

Question 14

Which of the following statements about the products of meiosis is correct?

Accepted Answer

Each of the four resulting cells is haploid and genetically distinct.

Question 15

A mutation occurs that prevents crossing over during Prophase I of meiosis. What is the most likely consequence for the resulting gametes?

Accepted Answer

The gametes will have less genetic variation than normal.

Question 16

Which of the following best describes the outcome of fertilization in humans?

Accepted Answer

Fusion of two haploid gametes ($$n = 23) to $$form a diploid zygote ($$2n = 46)$$

Question 17

Which of the following is true regarding the separation of chromosomes during meiosis and mitosis?

Accepted Answer

In meiosis I, homologous chromosomes separate; in mitosis, sister chromatids separate.

Question 18

A cell with $$2n = 8$$ chromosomes undergoes meiosis. How many chromosomes will each of the four resulting cells have after meiosis II, and will the chromatids be duplicated or unduplicated?

Accepted Answer

Each cell will have $$n = 4$$ unduplicated chromosomes.

Question 19

Which of the following best explains why meiosis is essential for sexual reproduction in animals?

Accepted Answer

It reduces the chromosome number by half, preventing chromosome doubling in each generation.

Question 20

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

Accepted Answer

Exchange of genetic material between homologous chromosomes, leading to new allele combinations.

Meiosis and Sexual Life Cycles: Chromosome Behavior and Genetic Variation

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