Question 1

Which of the following best explains why sexual reproduction leads to greater genetic diversity than asexual reproduction?

Accepted Answer

Sexual reproduction involves the fusion of two haploid gametes, each with unique combinations of alleles due to crossing over and independent assortment.

Question 2

During which specific stage of meiosis does crossing over occur, and what is its significance?

Accepted Answer

Crossing over occurs during pachytene of prophase I and increases genetic variation among gametes.

Question 3

A human cell with 46 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 4

If nondisjunction occurs during anaphase I of meiosis, what is the most likely outcome for the resulting gametes?

Accepted Answer

Half of the gametes will have an extra chromosome, and half will be missing one chromosome.

Question 5

Which of the following best describes a heterozygous genotype?

Accepted Answer

The individual has two different alleles for a gene, such as $$Aa.$$

Question 6

What is the primary function of the synaptonemal complex during meiosis?

Accepted Answer

To hold homologous chromosomes together during prophase I, facilitating crossing over.

Question 7

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

Accepted Answer

Homologous chromosome pairs (tetrads) align at the metaphase plate.

Question 8

A cell with genotype $$Aa$$ undergoes meiosis. Assuming independent assortment and no crossing over, what are the possible genotypes of the resulting gametes?

Accepted Answer

$$A$$ and $$a$$

Question 9

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

Accepted Answer

One chromosome with a deletion and the other with a duplication of genetic material.

Question 10

In humans, what is the result of fertilization between two haploid gametes?

Accepted Answer

A diploid zygote with $$46$$ chromosomes.

Question 11

Which stage of the cell cycle is responsible for DNA replication?

Accepted Answer

S phase

Question 12

A genetic disorder is caused by trisomy 21. Which meiotic error most commonly leads to this condition?

Accepted Answer

Nondisjunction during anaphase I

Question 13

Which of the following statements about gamete production in humans is correct?

Accepted Answer

Sperm are produced continuously, while females are born with all their oocytes arrested in diplotene.

Question 14

Which of the following best describes the difference between genotype and phenotype?

Accepted Answer

Genotype is the genetic makeup, while phenotype is the observable physical properties influenced by both genotype and environment.

Question 15

Which process is responsible for the separation of homologous chromosomes?

Accepted Answer

Anaphase I of meiosis

Question 16

In a plant life cycle, which process restores the diploid number after gametes are produced?

Accepted Answer

Fertilization

Question 17

Which of the following is a unique feature of meiosis II compared to meiosis I?

Accepted Answer

Sister chromatids separate.

Question 18

A mutation causes a cell to skip the S phase of the cell cycle. What is the most likely consequence?

Accepted Answer

The cell will not replicate its DNA and cannot properly divide.

Question 19

Which of the following is true about parthenogenesis as seen in Komodo dragons?

Accepted Answer

Offspring inherit only maternal alleles, but allele combinations can differ due to meiosis.

Question 20

If a diploid cell with 8 chromosomes undergoes meiosis, how many chromosomes will each resulting gamete have?

Accepted Answer

$$4$$

Meiosis, Sexual Reproduction, and Genetic Variation: Study Guide

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