Learning Outcomes
i. Identify the components of a seed and describe their structure.
ii. Understand the role of seeds as reproductive units in the life cycle of flowering plants.
iii. Recognize how seeds ensure the survival and propagation of plant species.
i. Structure of Seeds
Seed Coat: The outer protective layer that shields the embryonic plant from mechanical damage and disease.
Embryo: A young plant in its earliest phase of development, consisting of the radicle (future root), the hypocotyl (stem), epicotyl (precursor of the leaves), and cotyledons (seed leaves).
Endosperm: A tissue that provides nourishment to the developing embryo in the form of starch, and sometimes oils and protein.
ii. Role as Reproductive Units: Seeds are the main means by which many plants reproduce and spread to new locations. They contain the genetic information from the parent plant and can lie dormant until conditions are right for germination.
iii. Ensuring Survival and Propagation
Dormancy: Many seeds can enter a period of dormancy, allowing them to survive in harsh conditions until they are favorable for growth.
Dispersal Mechanisms: Seeds have various adaptations for dispersal, including wind, water, and animals, which help spread the species and reduce competition.
Nutrient Supply: The endosperm or cotyledons provide essential nutrients to support the early growth of the seedling once germination occurs.
In conclusion, seeds are vital for the reproduction and dispersal of flowering plants. Their structure is highly adapted to protect the embryo, provide nourishment, and ensure that the plant can reproduce and spread effectively. Understanding the function and structure of seeds is fundamental to the study of botany, agriculture, and ecology.
