Seeds

Definition

Seeds are reproductive structures that contain a developing embryo and a supply of nutrients, protected by a seed coat. They represent a crucial evolutionary advancement in plants, allowing them to reproduce and disperse efficiently in diverse environments, ultimately contributing to the establishment of early land plants.

5 Must Know Facts For Your Next Test

1. Seeds provide a protective coat that safeguards the embryo from environmental stresses and predation, enhancing survival chances.
2. They are capable of remaining dormant for extended periods, allowing them to survive unfavorable conditions until the environment is suitable for germination.
3. The development of seeds allowed early land plants to colonize a variety of habitats, leading to greater biodiversity and ecological complexity.
4. Seeds can be dispersed by various methods, including wind, water, and animals, facilitating the spread of plant species over large distances.
5. The evolution of seeds was pivotal in the transition from simple spore-based reproduction to more complex forms of reproduction, impacting plant evolution significantly.

Review Questions

• How did the evolution of seeds contribute to the success and diversification of early land plants?
  • The evolution of seeds allowed early land plants to reproduce more effectively and adapt to different environments. Seeds provide protection for the embryo and nutritional support, which enhances survival rates. This capability to remain dormant during unfavorable conditions and germinate when conditions improve facilitated colonization of various habitats, leading to increased biodiversity among early land plants.
• Discuss the differences between gymnosperms and angiosperms in terms of seed structure and reproductive strategies.
  • Gymnosperms produce seeds that are exposed on cones, whereas angiosperms develop seeds within a fruit following fertilization. This difference in seed structure reflects distinct reproductive strategies; angiosperms often rely on animal pollinators and fruit dispersal mechanisms, while gymnosperms primarily depend on wind for pollen distribution. This variation has allowed angiosperms to dominate many ecosystems due to their efficient reproductive strategies.
• Evaluate the ecological impact of seed evolution on terrestrial ecosystems and its implications for future plant diversity.
  • The evolution of seeds drastically transformed terrestrial ecosystems by enhancing plant reproductive success and ecological resilience. As seeds allowed for greater dispersal and survival across varied environments, this led to increased plant diversity and complex interactions within ecosystems. The ability to occupy diverse niches paved the way for future evolutionary adaptations, setting the stage for ongoing diversification in plant life as environments continue to change.

Related terms

Gymnosperms: A group of seed-producing plants that includes conifers, characterized by having seeds exposed on cones rather than enclosed in fruits.

Angiosperms: Flowering plants that produce seeds enclosed within a fruit, representing the most diverse group of land plants.

Pollination:

The transfer of pollen from the male part of a flower to the female part, leading to fertilization and the formation of seeds.