Fertilization involves the fusion of which type of cells?

• A. Haploid gametes
• B. Diploid somatic cells
• C. Diploid gametes
• D. Zygotes

Answer: (A)

Fertilization involves the fusion of haploid gametes, which are sex cells that each contain a single set of chromosomes. These gametes are produced by meiosis, and when a sperm meets an egg, their haploid genomes combine to restore the diploid chromosome number in the zygote. This zygote then begins development and divides by mitosis to form the embryo. The other options don’t fit because somatic cells are diploid and do not fuse during fertilization; there aren’t diploid gametes in normal sexual reproduction; and the zygote is the product of fertilization, not the cell that fuses.