Question

what role does fertilization play in restoring the diploid number of chromosomes? it combines two haploid cells to form a diploid zygote. it creates genetic mutations within the zygote to be passed down. it halves the number of chromosomes in all cells. it separates homologous chromosomes with a zygote.

Explanation:

Fertilization is the process where a sperm (haploid) and an egg (haploid) fuse. A haploid cell has half the number of chromosomes. When two haploid cells combine, their chromosome numbers add up. For example, if each haploid cell has \(n\) chromosomes, the resulting zygote has \(n + n=2n\) chromosomes. A diploid cell has \(2n\) chromosomes.

• The second option about genetic mutations is incorrect as fertilization itself does not create mutations (mutations can occur due to other factors like radiation, chemical exposure etc. but not as a direct result of fertilization).
• The third option is wrong because fertilization does not halve chromosome numbers; meiosis is the process that halves chromosome numbers in cells (to form gametes).
• The fourth option is incorrect. Separating homologous chromosomes occurs during meiosis (specifically meiosis I), not during fertilization.

Answer:

It combines two haploid cells to form a diploid zygote.