Question

Tegmen is the name of
A. Embryo shoot
B. Embryonic node
C. Cotyledon
D. Inner seed coat

Answer 1

Hint: The seed comprises the tegmen. Seeds are produced by pollen after fertilisation. A seed has two essential elements, the coat of seed and an embryo. The zygote produces the foetus, while the ovule integument is responsible for the semi skin.

Complete answer: The layer of a seed that consists of two layers or integuments is the outermost coating layer. The external integument leads to the external layer, the so-called testa, and the inner integument leads to the internal layer, known as a testa. Testa is hard and leathery that guards seeds against harsh conditions. Tegmen is a fragile seed layer that is also a shielding unit. The embryo consists of one or two cotyledons, a plumule and an embryonic axis. Seeds with one cotyledon are referred to as monocotyledonous seeds, whereas seeds with two cotyledons are referred to as dicotyledonous seeds. Cotyledons are associated with the embryonic axis and act as meal sources. The plumule grows and contributes to germination of the plant, while the radicle develops to the important root. Studying the options we can decipher that,
i. The embryonic axis lies between the two plumula cotyledons (embryo shoot).
ii. The cotyledons are laterally linked at the embryonic node to the curved embryonic axis.
iii. Two large white kidney-shaped structures known as cotyledons form the majority of the embryo (or seed leaves).
Hence, option D is the correct answer.

Note: The ovule also consists of funicle and chalaza. Funicle is a stalk-like structure in the seed that helps to restore the ovule to the placenta and the ovary to the pericarp. The foundation from which the integuments arise is the chalaza. At the bottom of the nucellus, is a swollen portion.