AP BIOLOGY

Detailed explanation-1: -A seed coat protects the internal parts of a seed. The seed coat has two layers. The outer layer is thick and known as the testa.

Detailed explanation-2: -The testa of higher plant seeds protects the embryo against adverse environmental conditions. Its role is assumed mainly by controlling germination through dormancy imposition and by limiting the detrimental activity of physical and biological agents during seed storage.

Detailed explanation-3: -The outer covering of a seed is called the seed coat. Seed coats help protect the embryo from injury and also from drying out. Seed coats can be thin and soft as in beans or thick and hard as in locust or coconut seeds.

Detailed explanation-4: -In the case of the germination of a monocotyledonous plant seed, the coleorhiza is the first part to grow out of the seed coat, whereas during the germination of a dicotyledonous plant seed, the radicle grows out of the seed coat first [5].

Detailed explanation-5: -seed development form the seed coat (testa). The product is a structure in which the embryo is protected from temperature extremes by its state of desiccation and is often guarded from further drying and from mechanical or biological degradation by the seed coats.