Question

Testa and tegmen of a seed are
A. Active Embryo
B. Micropyle end
C. Chalazal end
D. Protective layer

Answer 1

Hint:A seed is an embryonic plant that is wrapped in a protective outer covering. Seed formation is part of the process of reproduction in most plants. Normally, a seed contains two basic parts- an embryo and a seed coat.

Complete answer:
The seed is made up of a coat of seed and an embryo. The embryo is made up of a radicle, an embryonic axis and one or two cotyledons. Seeds are formed from ovules after fertilisation.
Each ovule comprises one or two protective envelopes known as integuments. Integuments encircle the nucleus except at the tip where a narrow opening called a micropyle is arranged. The chalaza, which represents the basal portion of the ovule lies opposite the micropylar end.
The mass of cells called the nucellus is contained within the integuments. Nucellus cells have sufficient nutrient reserve resources. The embryo sac or female gametophyte is found in the nucellus. Generally, an ovule has a single embryo sac formed from a megaspore.
The seed coat is the outermost component of the seed. It protects the developing embryo. There are two layers of the seed coat, the outer testa and the inner tegmen. While the ovules grow into seeds, the ovaries evolve into fruit. The development of the ovules into seeds and the ovaries into fruit occurs at the same time. The wall of the ovaries grows into a layer of fruit called pericarp.

Thus the correct answer is option D i.e., Protective layer.

Note:In most monocotyledons and dicotyledons, the endosperm forms a supply for the embryo. A seed coat protects the baby plant from any injury or drying out.