Question 1

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

Accepted Answer

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

Question 2

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

Accepted Answer

$$23$$

Question 3

Which process is responsible for the exchange of genetic material between homologous chromosomes during meiosis?

Accepted Answer

Crossing over

Question 4

In which phase of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Question 5

If a diploid organism has a haploid number $$n = 8$$, how many possible combinations of chromosomes can be produced by independent assortment during gamete formation?

Accepted Answer

$$2^8 = 256$

Question 6

Which of the following statements about asexual reproduction is correct?

Accepted Answer

It produces genetically identical offspring to the parent.

Question 7

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

Accepted Answer

It increases genetic variation among offspring.

Question 8

Which event occurs during prophase I of meiosis but not during mitosis?

Accepted Answer

Synapsis and crossing over

Question 9

A mutation occurs in a gene located at a specific locus on a chromosome. What is the most likely result?

Accepted Answer

A new allele of the gene is created.

Question 10

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

Accepted Answer

Sister chromatids are identical copies formed during DNA replication, while homologous chromosomes are similar but not identical chromosomes from each parent.

Question 11

During which stage of the human life cycle does fertilization occur, and what is the result?

Accepted Answer

After gametes fuse; a diploid zygote is formed.

Question 12

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

Accepted Answer

Replication of DNA during S phase

Question 13

A scientist observes a cell with two sets of chromosomes (2n) that divides to produce four cells, each with one set of chromosomes (n). Which process is being observed?

Accepted Answer

Meiosis

Question 14

If a human egg with an extra chromosome (n = 24) is fertilized by a normal sperm (n = 23), what will be the chromosome number in the resulting zygote?

Accepted Answer

$$2n = 47$$

Question 15

Which of the following is true about the products of meiosis in humans?

Accepted Answer

They are haploid cells with unique genetic combinations.

Question 16

A plant species has a diploid number of 10 chromosomes. How many chromosomes will be present in each spore after meiosis?

Accepted Answer

$$5$$

Question 17

Which of the following best describes the role of mutations in evolution?

Accepted Answer

Mutations are the original source of genetic diversity.

Question 18

Which of the following events occurs in both mitosis and meiosis?

Accepted Answer

Separation of sister chromatids

Question 19

Why does random fertilization increase genetic variation in a population?

Accepted Answer

It allows any sperm to fuse with any egg, combining different genetic backgrounds.

Question 20

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

Accepted Answer

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

Meiosis and Sexual Life Cycles: Study Notes for Biology Students

Study Guide - Practice Questions

Study Guide - Flashcards