Question 1

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

Accepted Answer

Because each sibling inherits a random combination of alleles due to independent assortment and crossing over during meiosis.

Question 2

What is the primary difference between asexual and sexual reproduction?

Accepted Answer

Asexual reproduction produces genetically identical offspring, while sexual reproduction produces genetically diverse offspring.

Question 3

If a human cell has 46 chromosomes, how many chromosomes will be present in each gamete after meiosis?

Accepted Answer

$$23$$

Question 4

Which process is responsible for reducing the chromosome number from diploid to haploid in sexually reproducing organisms?

Accepted Answer

Meiosis

Question 5

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

Accepted Answer

Prophase I; it increases genetic variation by exchanging genetic material between homologous chromosomes.

Question 6

A diploid organism has a haploid number $$n = 8. $$According to the formula $$2^n$$, how many possible chromosome combinations can be produced by independent assortment during gamete formation?

Accepted Answer

$$256$$

Question 7

Which of the following events is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 8

What is the result of fertilization in humans?

Accepted Answer

A diploid zygote with $$2n = 46$$ chromosomes

Question 9

Which mechanism does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during S phase

Question 10

A geneticist observes a karyotype with 23 pairs of chromosomes. What can be concluded about the cell?

Accepted Answer

It is a human somatic cell in diploid state.

Question 11

Which of the following best describes the relationship between genes, loci, and traits?

Accepted Answer

A gene is a segment of DNA at a specific locus that codes for a trait.

Question 12

In which phase of meiosis do homologous chromosomes separate, and what is the result?

Accepted Answer

Anaphase I; homologous chromosomes are pulled to opposite poles, reducing chromosome number by half.

Question 13

Which of the following is a direct result of random fertilization?

Accepted Answer

A zygote with a unique combination of alleles from both parents

Question 14

Which statement about mitosis and meiosis is correct?

Accepted Answer

Mitosis produces genetically identical cells, while meiosis produces genetically diverse cells.

Question 15

A mutation occurs in a gene that codes for eye color. What is the most likely result?

Accepted Answer

A new allele for eye color is created, potentially leading to variation in offspring.

Question 16

If a plant species has a diploid number of $$2n = 18$$, how many chromosomes will be found in each of its gametes?

Accepted Answer

$$9$$

Question 17

Which of the following best describes a clone?

Accepted Answer

An organism that is genetically identical to its parent, produced by asexual reproduction.

Question 18

Which event during meiosis increases genetic diversity by producing recombinant chromosomes?

Accepted Answer

Crossing over during prophase I

Question 19

Why is the number of possible genetic combinations in humans so high?

Accepted Answer

Because of independent assortment, crossing over, and random fertilization.

Question 20

Which of the following is true regarding homologous chromosomes?

Accepted Answer

They carry genes controlling the same inherited characters, but may have different alleles.

CH 13- Meiosis and Sexual Life Cycles: Mechanisms and Genetic Variation

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