The purpose of the hard seed coat is to provide protection to the mature seed. Option a is correct. The hard seed coat, also known as the testa, is the outer covering of a seed. It serves several important functions related to seed development, dispersal, and viability.
- Protection: The hard seed coat acts as a physical barrier, shielding the delicate embryo and its food reserves from mechanical damage, pathogens, and environmental stresses. It provides a layer of defense against physical impact, desiccation (drying out), and microbial attacks. This protection ensures the survival and integrity of the embryo within the seed.
- Dormancy regulation: The hard seed coat plays a role in regulating seed dormancy, which is a period of inactivity or suspended growth in seeds. It prevents premature germination of the seed under unfavorable conditions, such as drought or cold temperatures. The impermeability of the seed coat to water and gases helps maintain seed dormancy until suitable conditions for germination are present.
- Water regulation: The hard seed coat acts as a barrier to control water uptake by the seed. It prevents excessive absorption of water, which could lead to premature germination or damage to the developing embryo. This regulation ensures that the seed remains dormant and viable until the appropriate conditions for germination are met.
- Dispersal aid: The hard seed coat also aids in the dispersal of seeds. In some plant species, the seed coat may have specialized structures or adaptations that enable attachment to animal fur or feathers, or facilitate wind dispersal. The durability and strength of the seed coat help seeds survive the rigors of dispersal and increase the chances of successful colonization in new habitats.
- Longevity and viability: The hard seed coat contributes to the longevity and viability of seeds during storage. It provides a protective barrier against damage caused by environmental factors, such as light, temperature fluctuations, and microbial degradation. By preserving the integrity of the embryo and its food reserves, the seed coat enhances the seed's ability to remain viable and germinate successfully even after prolonged periods of storage.
In summary, the hard seed coat serves multiple functions, including protection of the mature seed, regulation of dormancy, control of water uptake, aid in dispersal, and enhancement of seed viability during storage. These features ensure the survival, successful germination, and colonization of plants in different environments.
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