Question 1

Which of the following best describes the difference between asexual and sexual reproduction in terms of genetic variation?

Accepted Answer

Sexual reproduction increases genetic variation among offspring due to mechanisms such as crossing over and independent assortment.

Question 2

During meiosis I, homologous chromosomes separate. Which process ensures that each gamete receives a random mix of maternal and paternal chromosomes?

Accepted Answer

Independent assortment

Question 3

Which phase of meiosis is responsible for the exchange of genetic material between homologous chromosomes, increasing genetic diversity?

Accepted Answer

Prophase I

Question 4

A diploid cell with $$2n = 8$$ undergoes meiosis. How many chromosomes will each gamete contain after meiosis is complete?

Accepted Answer

$$4$$

Question 5

Which of the following events does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during interphase

Question 6

If a human somatic cell contains $$46$$ chromosomes, how many chromosomes are present in a human gamete after meiosis?

Accepted Answer

$$23$$

Question 7

Which term describes the physical location where crossing over occurs between homologous chromosomes?

Accepted Answer

Chiasmata

Question 8

A zygote is formed by the fusion of two gametes. If each gamete is haploid, what is the chromosome number of the zygote?

Accepted Answer

Twice the number of chromosomes as a gamete

Question 9

Which of the following best explains why siblings from the same parents can have different genetic traits?

Accepted Answer

Independent assortment and crossing over during meiosis create unique combinations of alleles in gametes.

Question 10

Which of the following is a direct result of synapsis during meiosis?

Accepted Answer

Pairing of homologous chromosomes and potential for crossing over

Question 11

Which process is responsible for the restoration of the diploid chromosome number in sexually reproducing organisms?

Accepted Answer

Fertilization

Question 12

A geneticist observes that a certain trait is inherited independently of another trait. Which principle does this observation support?

Accepted Answer

Law of Independent Assortment

Question 13

Which of the following statements about meiosis II is correct?

Accepted Answer

Sister chromatids separate during meiosis II.

Question 14

If a mutation occurs during crossing over in meiosis I, which cells are most likely to carry the mutation?

Accepted Answer

Only the gametes produced from that meiotic event

Question 15

Which of the following best describes the role of fertilization in genetic variation?

Accepted Answer

It randomly combines two sets of chromosomes from different gametes, increasing genetic diversity.

Question 16

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

Accepted Answer

Meiosis occurs only in somatic cells, while mitosis occurs in gametes.

Question 17

Which event during meiosis is most directly responsible for the formation of recombinant chromosomes?

Accepted Answer

Crossing over during prophase I

Question 18

A scientist is studying a cell that has just completed meiosis I. Which of the following statements is true about the resulting cells?

Accepted Answer

Each cell is haploid and contains sister chromatids.

Question 19

Which of the following best explains why independent assortment and crossing over are important for evolution?

Accepted Answer

They increase genetic variation, providing raw material for natural selection.

Question 20

If an organism has a karyotype showing $$n = 6$$, how many chromosomes will be present in its somatic cells?

Accepted Answer

$$12$$

L12: Principles, Processes, and Genetic Variation

Study Guide - Practice Questions