In addition to seeds, which of the following characteristics is unique to seed-producing plants?

• A. Alternation of generations
• B. Presence of pollen grains
• C. Cell walls made of cellulose
• D. Photosynthetic ability

Answer: (B)

Verified step by step guidance

1. Understand the concept of seed-producing plants: Seed-producing plants, also known as spermatophytes, include gymnosperms and angiosperms. They have unique adaptations that distinguish them from other plant groups.
2. Review the characteristic 'Alternation of generations': This is a common feature in all plants, not unique to seed-producing plants. It refers to the life cycle alternating between a haploid gametophyte and a diploid sporophyte generation.
3. Examine 'Cell walls made of cellulose': This is a universal trait of all plants, algae, and some protists. It is not specific to seed-producing plants.
4. Analyze 'Photosynthetic ability': Photosynthesis is a shared characteristic among most plants, algae, and some bacteria. It is not exclusive to seed-producing plants.
5. Focus on 'Presence of pollen grains': Pollen grains are unique to seed-producing plants. They are male gametophytes that facilitate reproduction without the need for water, a key adaptation for terrestrial environments.