In humans, how many chromosomes does a typical zygote contain immediately after fertilization?

• A. 48
• B. 46
• C. 23
• D. 44

Answer: (B)

Verified step by step guidance

1. Understand that a zygote is formed by the fusion of two gametes: one sperm and one egg.
2. Recall that human gametes (sperm and egg) are haploid cells, meaning they each contain half the number of chromosomes found in typical body cells.
3. Know that the haploid number of chromosomes in humans is 23, so each gamete contributes 23 chromosomes.
4. When fertilization occurs, the two haploid sets combine to restore the diploid number of chromosomes.
5. Therefore, the total number of chromosomes in a typical human zygote immediately after fertilization is calculated as \$23 + 23 = 46$ chromosomes.