Plant kingdom practice · Mixed difficulty

Option B is correct because both statements are true: Algin is indeed obtained from algae, and Vinblastin is a secondary metabolite, but the two facts are unrelated.

Option B (Pollination) is correct because pollination is the process of transferring pollen grains from the anther to the stigma of a flower.

Option D (Self-fertilization is prevented) is correct because if antherozoids and eggs mature at different times, self-fertilization is avoided, promoting cross-fertilization.

Option B (80) is correct because in both angiosperms and gymnosperms, each zygote requires one egg and one sperm, and each egg and sperm requires one meiosis. For 64 zygotes, 64 eggs and 64 sperms are needed, thus 64 + 16 = 80 meiosis in angiosperms (64 for eggs, 16 for pollen grains) and 64 + 64 = 128 meiosis in gymnosperms (64 for eggs, 64 for pollen grains). However, the question asks only about the number of meiosis for the formation of 64 zygotes, which is 64 for eggs and 16 for pollen grains in angiosperms and 64 for eggs and 16 for pollen grains in gymnosperms. Therefore, the number of meiosis for the formation of 64 zygotes is 80 in angiosperms and 80 in gymnosperms.

Option C (They have no ovary) is correct because fruits develop from the ovary, and gymnosperms lack an ovary, hence they do not produce fruits.

Option A is correct because in gymnosperms, the nucellus (the megasporangium) is surrounded by one or two integuments, and the entire structure is called the ovule.

Option D (Volvox - Colonial form, non-flagellated) is not correctly matched because Volvox is a colonial form of algae, but each individual cell within the colony *is* flagellated, allowing the colony to move.

Option A (Bryophyte) is correct because Sphaerocarpus is a genus of liverworts, which are classified as bryophytes.

Option B (If both the assertion and reason are true but the reason is not a correct explanation of the assertion) is correct because while both statements are true, the reason (being a unicellular green algae) doesn't fully explain why it's used as a food supplement by space travelers. The nutritional value and ease of cultivation are more direct reasons.

Option A (Pinus) is correct because cleavage polyembryony, where multiple embryos develop from a single zygote, is a characteristic feature of Pinus.

Option C (upper antheridium and lower oogonium) is wrong because in Chara, the oogonium (nucule) is located above the antheridium (globule).