key term - Seed Coat

Definition

The seed coat is the protective outer covering of a seed, formed from the outer layers of the ovule after fertilization. It serves as a barrier against physical damage and desiccation, ensuring the survival of the embryo inside. The seed coat also plays a crucial role in seed dormancy and germination, as it can control the passage of water and gases into the seed.

5 Must Know Facts For Your Next Test

1. The seed coat is primarily made up of hard, protective tissues that vary in thickness and texture depending on the species.
2. It can have specialized structures like hooks or wings to aid in seed dispersal by wind or animals.
3. In some species, the seed coat can inhibit water absorption, thus preventing premature germination until conditions are favorable.
4. Seed coats can also contain chemical inhibitors that prevent germination until exposed to certain environmental cues, like fire or cold temperatures.
5. Damage to the seed coat can result in reduced viability and increased susceptibility to pathogens.

Review Questions

• How does the structure of the seed coat contribute to its protective functions for the seed?
  • The structure of the seed coat is designed to provide protection against physical damage, pathogens, and environmental stress. Its thick and tough exterior serves as a barrier that helps prevent desiccation and shields the delicate embryo from harsh conditions. Additionally, some seed coats have specialized adaptations such as hard surfaces or chemical inhibitors that further enhance their protective role, ensuring that the seed remains viable until conditions are suitable for germination.
• In what ways does the seed coat influence the process of germination in different plant species?
  • The seed coat plays a significant role in controlling germination timing across various plant species. Its thickness and permeability can either facilitate or inhibit water absorption, which is essential for initiating germination. In some cases, seeds may require specific environmental triggers to weaken or break down the seed coat, allowing water and oxygen to penetrate. This variability in seed coat characteristics influences when and how different plants grow under specific conditions.
• Evaluate how understanding the functions of the seed coat can enhance agricultural practices related to crop production.
  • Understanding the functions of the seed coat can greatly improve agricultural practices by informing decisions about seed treatment and preparation for planting. For instance, knowledge about how certain seed coats affect germination can lead to better strategies for sowing seeds at optimal times or conditions. Additionally, insights into enhancing or altering seed coat properties could help in developing crops that are more resistant to environmental stresses or pests. This knowledge can ultimately lead to higher crop yields and improved food security.

Related terms

Embryo: The early developmental stage of a seed that contains the plant's future root, stem, and leaves.

Endosperm: A nutrient-rich tissue within seeds that provides essential nourishment to the developing embryo.

Germination: The process by which a seed develops into a new plant, beginning when the seed absorbs water and ends with the emergence of the seedling.