Massachusetts Comprehensive Assessment System (MCAS) Biology Practice Test

What cellular process produces haploid cells from a diploid cell?

1. Fertilization

2. Meiosis

3. Mitosis

4. Binary fission

The correct answer is: Meiosis

Meiosis is the cellular process responsible for producing haploid cells from a diploid cell. In organisms that reproduce sexually, meiosis is crucial for creating gametes (sperm and egg cells). A diploid cell, which contains two sets of chromosomes (one from each parent), undergoes two rounds of division during meiosis, ultimately resulting in four haploid cells, each with only one set of chromosomes. This reduction in chromosome number is essential for maintaining the species' chromosome count across generations, ensuring that when fertilization occurs, the resulting zygote has the correct diploid number. In contrast, fertilization involves the fusion of two haploid gametes to form a diploid zygote, while mitosis is a process of cell division that produces two identical diploid daughter cells, maintaining the original chromosome number. Binary fission is a form of asexual reproduction seen in prokaryotic organisms, resulting in two identical cells and is not involved in the production of haploid cells.