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🐇honors biology review

key term - Embryo

Citation:

Definition

An embryo is an early stage of development in a multicellular organism, particularly after fertilization when the zygote undergoes rapid cell division and differentiation. In plants, the embryo develops from the fertilized ovule and is crucial for the formation of the new plant, as it will eventually grow into the mature structure. The embryo contains the essential genetic information from both parent plants and serves as a foundation for the plant's growth and development.

5 Must Know Facts For Your Next Test

  1. Embryos in flowering plants are typically formed within seeds, which provide protection and nourishment during their early development.
  2. The embryo consists of three main parts: the hypocotyl (which becomes part of the stem), the radicle (which develops into the root), and cotyledons (the first leaves).
  3. In angiosperms, fertilization occurs when pollen reaches the ovule, leading to the formation of an embryo inside the seed.
  4. Embryonic development in plants is influenced by environmental factors such as temperature and moisture, which can affect germination rates.
  5. Some plant species have dormant embryos that can remain inactive for long periods until conditions are favorable for germination.

Review Questions

  • How does fertilization lead to embryo formation in plants?
    • Fertilization occurs when a pollen grain lands on the stigma of a flower and allows sperm cells to travel down to fertilize an ovule. This union forms a zygote, which then begins to divide rapidly, developing into an embryo within the seed. The newly formed embryo will eventually differentiate into various structures necessary for establishing a mature plant.
  • Discuss the importance of environmental conditions on embryonic development in plants.
    • Environmental conditions play a critical role in embryonic development by influencing germination and growth. Factors such as temperature, moisture availability, and light conditions can affect how quickly an embryo develops and when it transitions to germination. For instance, adequate moisture is essential for triggering metabolic processes that allow the embryo to grow, while extreme temperatures can inhibit or delay this process.
  • Evaluate the role of cotyledons in plant embryos and their significance during early growth stages.
    • Cotyledons are vital components of plant embryos that serve as the first leaves. They provide essential nutrients stored within the seed to support early growth before true leaves develop. The number of cotyledons can vary among plant species; monocots typically have one, while dicots have two. This difference plays an important role in identifying plant types and understanding their early growth strategies in response to environmental conditions.