Which statement about the gametophyte generation is correct?

Which statement about the gametophyte generation is correct?

• A. It is haploid and produces gametes by mitosis
• B. It is diploid and produces spores by meiosis
• C. It is diploid and produces gametes by mitosis
• D. It is haploid and produces spores by meiosis

Answer: (A)

In organisms with alternation of generations, the gametophyte is a haploid phase that uses mitosis to produce gametes. Because it already has one set of chromosomes, mitotic division preserves that chromosome number, giving rise to sperm and eggs that can fuse to form a diploid zygote. That zygote then grows into the diploid sporophyte, which makes haploid spores by meiosis, and those spores develop into new haploid gametophytes, continuing the cycle. The other descriptions mix up which generation is haploid or diploid and which cell division process produces spores or gametes, so they don’t fit the usual life cycle pattern.

In organisms with alternation of generations, the gametophyte is a haploid phase that uses mitosis to produce gametes. Because it already has one set of chromosomes, mitotic division preserves that chromosome number, giving rise to sperm and eggs that can fuse to form a diploid zygote. That zygote then grows into the diploid sporophyte, which makes haploid spores by meiosis, and those spores develop into new haploid gametophytes, continuing the cycle. The other descriptions mix up which generation is haploid or diploid and which cell division process produces spores or gametes, so they don’t fit the usual life cycle pattern.