Seeds

Definition

Seeds are reproductive structures produced by flowering plants, containing the embryo and a food supply, all encased within a protective coat. They play a vital role in the plant life cycle, serving as the primary means of reproduction and dispersal. In the context of photoassimilate partitioning, seeds act as important sinks that accumulate nutrients and energy derived from photosynthesis for growth and development.

5 Must Know Facts For Your Next Test

1. Seeds can remain dormant for long periods until environmental conditions are suitable for germination, allowing for survival through adverse conditions.
2. In many plants, seeds are produced through a process known as double fertilization, where one sperm fertilizes the egg while another forms the triploid endosperm.
3. The structure of seeds varies widely among plant species, impacting their dispersal mechanisms, such as wind, water, or animal assistance.
4. Seeds require a balanced supply of photoassimilates during development to ensure proper growth and establishment of the plant.
5. The process of photoassimilate partitioning is crucial for seed development, as it determines how much energy is allocated to the seed compared to other plant tissues.

Review Questions

• How do seeds function as sinks in photoassimilate partitioning within plants?
  • Seeds serve as critical sinks in the photoassimilate partitioning process because they store energy and nutrients necessary for their growth and development. During this phase, plants direct a significant portion of their photosynthesized products to seeds, ensuring they have adequate resources to germinate successfully. This allocation of resources supports not only the embryo's growth but also establishes future photosynthetic capabilities once the plant emerges.
• Discuss how environmental factors influence seed germination and subsequent plant establishment.
  • Environmental factors such as moisture, temperature, light availability, and oxygen levels play essential roles in seed germination. For instance, adequate moisture activates metabolic processes within the seed, while optimal temperatures can enhance enzymatic activity. Additionally, some seeds require specific light conditions to trigger germination. These factors ultimately influence how effectively a seed can utilize stored photoassimilates to establish itself as a healthy plant.
• Evaluate the role of endosperm in seed development and its relationship with photoassimilate partitioning.
  • Endosperm plays a crucial role in seed development by providing the necessary nutrients and energy reserves for the growing embryo during germination. The relationship between endosperm formation and photoassimilate partitioning is significant; as plants allocate resources during photosynthesis, these assimilates contribute to the development of endosperm. A well-developed endosperm ensures that the seed has sufficient energy reserves to support the initial stages of growth once it begins to germinate and grow into a new plant.

Related terms

Germination: The process by which a seed develops into a new plant, requiring water, warmth, and oxygen to trigger growth.

Endosperm: The nutrient-rich tissue within seeds that provides energy and sustenance to the developing embryo during germination.

Photosynthesis: The process by which green plants use sunlight to convert carbon dioxide and water into glucose and oxygen, serving as the basis for energy production in plants.