Seed

Definition

A seed is a reproductive structure that contains the embryo of a plant and is often surrounded by a protective coat, serving as a means for plants to reproduce and disperse. Seeds are crucial for the life cycle of angiosperms, facilitating germination and growth into new plants. They contain stored nutrients that support the embryo during its initial development after germination.

5 Must Know Facts For Your Next Test

1. Seeds can be classified into two main types: dicots and monocots, which refer to the number of cotyledons present in the seed.
2. The outer seed coat protects the embryo from physical damage and desiccation, allowing it to survive until conditions are right for germination.
3. Seeds can remain dormant for long periods, allowing them to withstand unfavorable environmental conditions until they can sprout.
4. Angiosperms produce seeds within fruits, which aid in seed dispersal by attracting animals that consume the fruit and excrete the seeds elsewhere.
5. Seeds can vary greatly in size and shape, with some being tiny like those of orchids, while others, like coconuts, are quite large.

Review Questions

• Compare and contrast the structures of seeds found in dicots and monocots and discuss their significance in angiosperm classification.
  • Dicots have two cotyledons in their seeds, while monocots have one. This difference is significant as it helps classify angiosperms into these two major groups. The structure of the seed influences not only how the plant develops after germination but also its overall growth patterns and characteristics. For instance, dicots typically have broader leaves with branching veins, while monocots usually exhibit long, narrow leaves with parallel veins.
• Evaluate the role of seeds in plant reproduction and survival, focusing on their advantages over other reproductive strategies.
  • Seeds play a critical role in plant reproduction by allowing for sexual reproduction and genetic diversity. Unlike spores, seeds contain an embryo and stored nutrients that support early growth, making them more resilient during unfavorable conditions. Additionally, seeds can remain dormant for extended periods until conditions are optimal for germination. This ability not only enhances survival rates but also allows plants to colonize new environments effectively.
• Analyze how the evolution of seeds has impacted angiosperm diversity and adaptation strategies in various ecosystems.
  • The evolution of seeds has significantly contributed to the diversification of angiosperms by allowing them to adapt to various environmental conditions. Seeds enable plants to spread across different habitats through mechanisms like wind, water, or animal dispersal. This adaptability has resulted in angiosperms occupying diverse ecological niches and developing various traits suited for survival. As a result, angiosperms represent one of the most successful plant groups on Earth today, dominating many terrestrial ecosystems.

Related terms

Embryo: The early developmental stage of a plant, contained within the seed, which will develop into the mature plant.

Cotyledon:

The first leaf or leaves that emerge from a seed during germination, which often provide initial nutrition to the developing plant.

Germination: The process by which a seed develops into a new plant, beginning when conditions are favorable for growth.