Question

Describe the structure of bean seed.

Answer 1

A bean is a kidney-shaped bean with the following structures:-

• Testa: The protective layer on the outside is called a testa which is usually very thin but tough. Within the surface of the testa, there is a tiny opening called the micropyle, which is where water can enter and start the germination process, breaking the dormant stage.
• Cotyledons: The cotyledons are the two large parts of the bean seed that takes up most of the space within the bean. These serve as food storage for the young bean plant until it grows large enough to support itself.
• Embryo: The embryo is the infant plant made up of two parts: the radicle, or the first root, and the plumule, or the first leaves. When water enters the micropyle, the radicle starts growing and moves down and out through the micropyle into the soil below and the plumule starts growing upwards.
• Hilum: The hilum, or scar, on a bean is the site where the bean originally attached to the fruit of the plant.