Question 1

Which of the following best describes the primary purpose of meiosis in sexually reproducing organisms?

Accepted Answer

To halve the chromosome number in gametes, ensuring offspring have the same chromosome number as parents

Question 2

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

Accepted Answer

Prophase I

Question 3

If a human cell has 23 pairs of chromosomes, how many unique gametes can be produced by independent assortment alone?

Accepted Answer

$$2^{23} = 8$$,388,608$$

Question 4

Which of the following statements about homologous chromosomes is TRUE?

Accepted Answer

They carry the same genes in the same order but may have different alleles

Question 5

What is the result of meiosis in terms of chromosome number and genetic diversity?

Accepted Answer

Four haploid cells, each genetically unique

Question 6

Which process during meiosis increases genetic variation by exchanging equivalent sections between homologous chromosomes?

Accepted Answer

Crossing over (recombination)

Question 7

A cell undergoes meiosis. How many times does the cell divide and how many times does DNA replicate?

Accepted Answer

Cell divides twice, DNA replicates once

Question 8

Which of the following best explains why offspring from sexual reproduction are not identical to their parents?

Accepted Answer

Meiosis introduces genetic variation through independent assortment and crossing over

Question 9

During Anaphase I of meiosis, which of the following occurs?

Accepted Answer

Homologous chromosomes are separated to opposite poles

Question 10

If two sets of identical twins marry and each couple has children, how genetically related are the children to each other?

Accepted Answer

They are as related as full siblings

Question 11

Which of the following is a key difference between mitosis and meiosis?

Accepted Answer

Mitosis involves one cell division, meiosis involves two

Question 12

Which structure connects homologous chromosomes during recombination in Prophase I?

Accepted Answer

Chiasma

Question 13

A mutation affects the meiosis-specific cohesins that hold homologous chromosomes together. What is the most likely consequence?

Accepted Answer

Homologous chromosomes fail to separate properly during Anaphase I

Question 14

Which equation correctly represents the chromosome number change from a diploid cell to gametes in humans?

Accepted Answer

$$2n = 46 \rightarrow n = 23$$

Question 15

Which of the following events does NOT occur during meiosis but does occur during mitosis?

Accepted Answer

Production of genetically identical daughter cells

Question 16

A genetic disorder causes failure of crossing over during meiosis. What is the most likely effect on gametes?

Accepted Answer

Gametes will have reduced genetic diversity

Question 17

Which of the following best explains the concept of independent assortment?

Accepted Answer

Each pair of chromosomes segregates independently of other pairs during meiosis

Question 18

Why is it important for gametes to be haploid?

Accepted Answer

To maintain the species-specific chromosome number after fertilization

Question 19

Which of the following is TRUE regarding the genetic relationship between gametes produced by the same individual?

Accepted Answer

Gametes are genetically unique due to independent assortment and crossing over

Question 20

A couple, both with 23 pairs of chromosomes, can produce how many possible unique offspring combinations due to independent assortment alone?

Accepted Answer

$$(2^{23}$$) 	imes $$(2^{23}) = 64$$,000,000,000$$

Meiosis: Mechanisms and Genetic Variation in Sexual Reproduction

Guida di studio - Domande di pratica