Which is a key difference between alternation of generations in plants and sexual reproduction in nonplant organisms?

• A. In plants, only the haploid stage is multicellular.
• B. In plants, the haploid generation is always dependent on the diploid generation.
• C. In other sexually reproducing organisms, the haploid and diploid generations are both multicellular.
• D. In other sexually reproducing organisms, the fusion of gametes forms a zygote before an embryo develops.
• E. In plants, the haploid and diploid stages are both multicellular.

Answer: (E)

Verified step by step guidance

1. Understand the concept of alternation of generations: In plants, alternation of generations refers to the life cycle that alternates between a multicellular haploid phase (gametophyte) and a multicellular diploid phase (sporophyte).
2. Identify the key difference: In plants, both the haploid (gametophyte) and diploid (sporophyte) stages are multicellular, which is a distinctive feature compared to many nonplant organisms.
3. Compare with nonplant organisms: In many nonplant sexually reproducing organisms, the haploid stage is typically unicellular (e.g., gametes like sperm and eggs), and only the diploid stage is multicellular.
4. Clarify the role of gametes: In nonplant organisms, the fusion of haploid gametes forms a diploid zygote, which then develops into a multicellular organism, but the haploid stage itself is not multicellular.
5. Conclude the key difference: The key difference is that in plants, both stages (haploid and diploid) are multicellular, whereas in many other sexually reproducing organisms, only the diploid stage is multicellular.