Question 1

Which of the following best describes the outcome of meiosis in a diploid organism?

Accepted Answer

Each gamete contains one copy of every gene.

Question 2

During which phase of meiosis does crossing over (homologous recombination) occur, and what is its significance?

Accepted Answer

Prophase I; it increases genetic variation by creating new allele combinations.

Question 3

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

Accepted Answer

Replication of DNA during S phase

Question 4

If a human cell with $$2n = 46$$ chromosomes undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 5

Which law explains why alleles for different genes are inherited independently of each other, and during which meiotic phase is this law physically manifested?

Accepted Answer

Law of Independent Assortment; Metaphase I

Question 6

A diploid cell with genotype AaBb undergoes meiosis without crossing over. According to independent assortment, what is the expected ratio of gamete genotypes?

Accepted Answer

1 AB : 1 Ab : 1 aB : 1 ab

Question 7

Which event marks the reduction of chromosome number from diploid to haploid during meiosis?

Accepted Answer

Separation of homologous chromosomes during Anaphase I

Question 8

In humans, how does fertilization restore the diploid chromosome number?

Accepted Answer

By combining two haploid gametes ($$n) to $$form a diploid zygote ($$2n)$$

Question 9

Which of the following best explains why sexual reproduction is advantageous for evolution?

Accepted Answer

It increases genetic diversity through recombination, independent assortment, and random fertilization.

Question 10

Which of the following statements about mitosis and meiosis is correct?

Accepted Answer

Mitosis produces two genetically identical diploid cells, while meiosis produces four genetically unique haploid cells.

Question 11

A cell is observed with homologous chromosomes paired and crossing over occurring. Which phase is this cell in?

Accepted Answer

Prophase I of meiosis

Question 12

If a mutation occurs during DNA replication prior to meiosis, what is the potential consequence for the resulting gametes?

Accepted Answer

Some gametes may carry the mutation, increasing genetic variation.

Question 13

Which process is responsible for the random distribution of maternal and paternal chromosomes into gametes?

Accepted Answer

Independent assortment

Question 14

A geneticist observes that a child has a combination of traits not seen in either parent. Which meiotic event most likely explains this observation?

Accepted Answer

Crossing over during Prophase I

Question 15

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

Accepted Answer

$$2n \rightarrow n$$

Question 16

Which of the following is a direct result of the Law of Segregation during gamete formation?

Accepted Answer

Each gamete receives only one allele of each gene.

Question 17

A cell with $$2n = 8$$ chromosomes undergoes meiosis. How many different combinations of chromosomes can be produced in the gametes due to independent assortment (ignore crossing over)?

Accepted Answer

$$2^4 = 16$

Question 18

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

Accepted Answer

Homologous chromosomes are similar chromosomes from each parent; sister chromatids are identical copies formed during DNA replication.

Question 19

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

Accepted Answer

Mitosis involves crossing over; meiosis does not.

Meiosis, Genetic Variation, and Mendelian Inheritance

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