Question

1. During a biology lab, students model gamete formation with chromosome cutouts. They notice that each sperm or egg ends up with only one copy of each chromosome, even though the parent cells started with pairs. A few students think that gametes have all the parent’s chromosomes, while others argue that gametes must have half the number.

Which process is being demonstrated here?

Responses

A. Fertilization, because gametes are combining to form a zygote.
A. Fertilization, because gametes are combining to form a zygote.

B. Mitosis, because cell division is producing identical cells.
B. Mitosis, because cell division is producing identical cells.

C. Meiosis, because gametes form with half the parent’s chromosome number.
C. Meiosis, because gametes form with half the parent’s chromosome number.

D. Mutation, because DNA sequences are changing during cell division.
D. Mutation, because DNA sequences are changing during cell division.

E. Environmental factors, because lifestyle changes affect the number of chromosomes.

Answer 1

C. Meiosis, because gametes form with half the parent’s chromosome number.

Explanation: Meiosis is the cell division process that produces gametes (sperm and egg). It reduces the chromosome number from diploid (pairs) to haploid (one of each chromosome), so each gamete gets only one copy. Fertilization is when two gametes combine to restore diploid number; mitosis produces identical somatic cells; mutation and environmental factors do not explain the halving of chromosome number.