Final answer:
After completing meiosis II, human sex cells have a total of 23 chromosomes. This is because meiosis produces haploid cells with half the number of chromosomes, ensuring that when two gametes combine, the resulting zygote has the normal diploid number of chromosomes, which is 46. Option A is correct.
Step-by-step explanation:
After completing meiosis II, human sex cells have a total of 23 chromosomes. In human cells, the parent cell has 46 chromosomes (23 pairs), so the cells produced by meiosis are haploid, meaning they have half the number of chromosomes. Therefore, the correct answer to the question is B. 23. Gametes are reproductive cells, such as sperm and eggs, which merge during fertilization to form a zygote with the normal diploid number of chromosomes, which is 46.
It is important to note that while somatic cells are diploid with 46 chromosomes, gametes are haploid with 23 chromosomes after meiosis. This reduction is crucial for sexual reproduction because it allows for the genetic information from both parents to combine without doubling the number of chromosomes in the offspring. The diversity in gametes is further increased by the random assortment of chromosomes during meiosis I and by crossing over events.