Angiosperms are different from all other plants because only they have
a. A vascular system.
b. Flowers.
c. Seeds.
d. A dominant sporophyte phase.

Verified step by step guidance

1. Understand the key characteristics of angiosperms: Angiosperms are flowering plants, and their defining feature is the presence of flowers, which are specialized structures for reproduction.
2. Review the characteristics of other plant groups: For example, gymnosperms also produce seeds but lack flowers, while non-vascular plants like mosses do not have a vascular system or seeds.
3. Analyze the options provided: Option (a) 'a vascular system' is not unique to angiosperms, as gymnosperms and ferns also have vascular systems. Option (c) 'seeds' is also not unique, as gymnosperms produce seeds as well. Option (d) 'a dominant sporophyte phase' is shared by angiosperms, gymnosperms, and ferns.
4. Focus on the unique feature of angiosperms: Flowers are exclusive to angiosperms and are used for sexual reproduction, often involving pollination by animals or wind.
5. Conclude that the correct answer is the feature that distinguishes angiosperms from all other plants, which is 'flowers' (option b).

Key Concepts

Angiosperms

Angiosperms, or flowering plants, are a group of plants characterized by the presence of flowers and the production of seeds enclosed within a fruit. This group is distinct from gymnosperms, which produce seeds that are not enclosed. Angiosperms are the most diverse group of land plants and play a crucial role in ecosystems and human agriculture.

Flowers

Flowers are the reproductive structures of angiosperms, facilitating sexual reproduction. They contain male (stamens) and female (pistils) reproductive organs, allowing for pollination and fertilization. The presence of flowers is a defining feature of angiosperms, enabling them to attract pollinators and enhance genetic diversity through cross-pollination.

Vascular System

The vascular system in plants consists of xylem and phloem, which transport water, nutrients, and sugars throughout the plant. While both angiosperms and gymnosperms possess a vascular system, it is not unique to angiosperms. The vascular system is essential for supporting larger plant structures and facilitating efficient resource distribution.