In a certain male individual, primary spermatocytes do not divide into secondary spermatocytes, yet still undergo spermiogenesis and form mature sperm. These sperm then fertilize a normal oocyte. What will be true of the zygote?
A)The zygote will have 46 chromosomes instead of 23.
B)The zygote will be diploid instead of haploid.
C)The zygote will have 69 chromosomes instead of 46.
D)The zygote will have only paternal chromosomes.

Question

Quizplus · Accepted Answer

Normally, primary spermatocytes undergo meiosis I to form two haploid secondary spermatocytes, each of which then undergoes meiosis II to produce haploid spermatids that mature into sperm. If primary spermatocytes do not divide into secondary spermatocytes but still form mature sperm, these sperm would retain the diploid number of chromosomes (46 in humans) instead of the haploid number (23). When such a diploid sperm fertilizes a normal haploid oocyte (23 chromosomes), the resulting zygote would have 69 chromosomes (46 from the sperm + 23 from the oocyte), making option C correct.

In a Certain Male Individual, Primary Spermatocytes Do Not Divide