BIOLOGY [2 Mark Question Answer]

Albuminous seed	Exalbuminous seed
These seeds possess endosperm	These seeds lack endosperm
In such seeds, food is stored mainly in the endosperm	In such seeds, food is stored only in the cotyledons.
Example - Castor, cereal s, grasses	Example - pea, gram, lentil

Coleorhiza	Coleoptile
It is the outer sheath covering the radicle in certain seeds.	It is the outer sheath covering the plumule in certain seeds.

This is because the seed is in a state of dormancy. In this case, even if all the favorable conditions are provided, the seed remains in a state of apparent inactivity and only germinates after a definite time has elapsed.

Epigeal germination - It is a type of germination in which cotyledons are pushed above the soil into the air and light. This occurs due to the rapid growth and elongation of the hypocotyl. Example - Bean, cotton, castor, papaya, onion, tamarind.

Hypogeal germination - In this germination, the seed remains inside the soil since epicotyl elongates faster than hypocotyl. Hence the cotyledons remain inside the soil. Example - Wheat, rice, pea, mango.

Dormancy - Seed dormancy is a condition of plant seeds that prevents germination under optimal environmental conditions. Here the seed is in a state of apparent inactivity and will not grow even if favorable conditions are provided, until a definite time has elapsed.

Albuminous seed - In some dicotyledons and monocotyledons, the
food is stored mainly in the endosperm. Such seeds are called albuminous seeds. Example - Seeds of castor, cereals, and grasses.

The process by which the dormant embryo of the seed resumes active growth and forms a seedling is known as germination.

If the seeds are sown too deep in the soil, they may not get sufficient oxygen required for respiration and hence will fail to germinate.