Question 1

Which of the following best explains why siblings from the same parents can look different from each other?

Accepted Answer

Because of genetic variation introduced by meiosis, including crossing over and independent assortment.

Question 2

What is the primary evolutionary advantage of sexual reproduction over asexual reproduction?

Accepted Answer

It increases genetic diversity, which can enhance adaptation to changing environments.

Question 3

A human somatic cell contains 46 chromosomes. After meiosis, how many chromosomes will each gamete contain?

Accepted Answer

$$23$$

Question 4

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

Accepted Answer

Homologous chromosomes pair up and crossing over occurs.

Question 5

If a diploid organism has a total of $$2n = 8$$ chromosomes, how many possible combinations of chromosomes can be produced in its gametes due to independent assortment alone?

Accepted Answer

$$2^4 = 16$

Question 6

Which of the following best describes a gene locus?

Accepted Answer

The physical location of a gene on a chromosome.

Question 7

During which stage of meiosis do homologous chromosomes separate and move toward opposite poles?

Accepted Answer

Anaphase I

Question 8

Which of the following statements about crossing over is TRUE?

Accepted Answer

It results in recombinant chromosomes with new combinations of alleles.

Question 9

A karyotype is most useful for which of the following purposes?

Accepted Answer

Identifying structural or numerical abnormalities in chromosomes.

Question 10

Which of the following is NOT a mechanism that contributes to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during mitosis.

Question 11

If a sperm cell contains an X chromosome, what will be the sex chromosome composition of the resulting zygote if it fertilizes a normal egg?

Accepted Answer

XX

Question 12

Which of the following best describes the difference between autosomes and sex chromosomes in humans?

Accepted Answer

Autosomes are the 22 pairs of non-sex chromosomes, while sex chromosomes are the X and Y chromosomes.

Question 13

Which process restores the diploid number of chromosomes in humans after meiosis?

Accepted Answer

Fertilization

Question 14

A mutation occurs in a gene located on a chromosome. Which of the following best describes the possible impact of this mutation?

Accepted Answer

It may change the trait associated with that gene, depending on the mutation's effect.

Question 15

Which of the following equations correctly represents the reduction in chromosome number during meiosis?

Accepted Answer

$$2n \rightarrow n$$

Question 16

Which of the following scenarios best illustrates the concept of independent assortment?

Accepted Answer

Homologous chromosomes align randomly at the metaphase plate during meiosis I, leading to different combinations of maternal and paternal chromosomes in gametes.

Question 17

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

Accepted Answer

Formation of recombinant chromosomes.

Question 18

Which of the following best explains why meiosis is essential for sexually reproducing organisms?

Accepted Answer

It maintains a constant chromosome number across generations by producing haploid gametes.

Question 19

A cell with a diploid number of $$2n = 12$$ undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$6$$

Question 20

Which of the following is TRUE regarding the products of meiosis in humans?

Accepted Answer

Each daughter cell is haploid and genetically unique.

Meiosis and Sexual Life Cycles: Genetics, Chromosomes, and Variation

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