Question

Scutellum is
A. Single fleshy cotyledon of Trapa
B. Single- shield shaped cotyledon of cereals
C. Covering of plumule
D. Covering of radicle

Answer 1

Hint: The monocots contain only one cotyledon which serves the function of providing nutrition to the developing embryo.

Complete answer:
Scutellum can be defined as the single- shield shaped cotyledon of the monocots or cereals.
The cereals or monocots contain only one cotyledon as suggested by the name. The seeds of the monocots are endospermic in nature. The embryo in monocots is small and is located at the one end of the endosperm. The separation of the embryo by the endosperm can be marked by the presence of a proteinaceous layer which is known as the aleurone layer. This embryo contains a single and shield shaped cotyledon which is called a scutellum. The embryo of the monocots seeds also consist of two structures called as plumule and radicle, which are present on the short axis which on germination will give rise to the shoot and root system respectively. These radicals and plumule present on the embryonal axis are enclosed in sheaths called as coleorhiza and coleoptile respectively.
The structure of the dicot seed is totally different from that of the monocots. As indicated by the name, dicot seed consists of two cotyledons. It has an outermost covering which is known as seed coat, which is further divided into two parts called testa which is outer part and tegmen, which is inner one. A scar is present on a seed coat called a hilum which provides attachment of the seed developing to the fruit. Hilum has a small pore above it called a micropyle.

So, the correct answer is (B).

Note: The cotyledons of the dicots and monocots are different in the structure as well as in the number of cotyledons which should be studied carefully.