Question 1

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

Accepted Answer

Homologous chromosomes are inherited from each parent and may have different alleles, while sister chromatids are identical copies formed during DNA replication.

Question 2

During which phase of meiosis does crossing over (homologous recombination) occur?

Accepted Answer

Prophase I

Question 3

If a diploid cell with $$2n = 8$$ chromosomes undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 4

What is the primary evolutionary advantage of meiosis in sexually reproducing organisms?

Accepted Answer

It increases genetic variation in the population.

Question 5

Which of the following events occurs during Anaphase I of meiosis but NOT during Anaphase of mitosis?

Accepted Answer

Homologous chromosomes are separated.

Question 6

A cell has just completed DNA replication and is about to enter meiosis. How many copies of each gene does it contain?

Accepted Answer

Four copies

Question 7

What is the consequence of nondisjunction during meiosis II?

Accepted Answer

Sister chromatids fail to separate, resulting in gametes with $$n+1$$, $$n-1$$, or $$n$$ chromosomes.

Question 8

Which of the following best explains why meiosis is necessary for sexual reproduction?

Accepted Answer

It maintains a constant chromosome number across generations by halving the chromosome number in gametes.

Question 9

Which stage of meiosis is most similar to mitosis in terms of chromosome behavior?

Accepted Answer

Meiosis II

Question 10

A human cell with 46 chromosomes undergoes meiosis. After meiosis II, how many chromosomes are present in each gamete?

Accepted Answer

$$23$$

Question 11

Which of the following processes contributes most directly to genetic variation during meiosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 12

If an error occurs during meiosis I such that both homologous chromosomes go to the same daughter cell, what is the likely outcome after fertilization?

Accepted Answer

The zygote will have an extra or missing chromosome (aneuploidy).

Question 13

Which of the following best describes the ploidy change during meiosis?

Accepted Answer

$$2n \rightarrow n$$

Question 14

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

Accepted Answer

Each gamete receives a random mix of maternal and paternal chromosomes.

Question 15

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

Accepted Answer

Mitosis involves crossing over, meiosis does not.

Question 16

After meiosis, each gamete contains:

Accepted Answer

One copy of every gene

Question 17

Which of the following scenarios would most likely result in Down syndrome (Trisomy 21)?

Accepted Answer

A nondisjunction event during meiosis I resulting in a gamete with two copies of chromosome 21.

Question 18

Which of the following best explains why chromosome number would double each generation without meiosis?

Accepted Answer

Gametes would be produced by mitosis, retaining the diploid number.

Question 19

Which of the following is true about the S phase in the context of meiosis?

Accepted Answer

DNA replication occurs only once before both meiotic divisions.

Question 20

Which of the following is a correct sequence of events during meiosis?

Accepted Answer

DNA replication → homologous chromosomes separate → sister chromatids separate

Meiosis: Mechanisms, Phases, and Biological Significance

Guida di studio - Domande di pratica

Study guide - Flashcard