BIOLOGY [2 Mark Question Answer]

Testa: The seed is protected by a thick outermost coat called the testa or seed coat.
Tegmen: Under the testa lies a very thin membrane called the tegmen.

IlIum: On one side of seed câat, there is a scar called hi hum, which marks the place where the seed was attached to the fiiüt wall.
Micropyle: Above the hilum is a small pore called micrope. The micropyle absorbs as much water as is required for germination

Radicle: In a seed, the radicle lies downwards near the lower pointed end of the grain. It gives rise to the root.
Plumule: In a seed the plumule lies upward near the cotyledon and gives rise to the shoot.

Stigma: It is the terminal knob-like part, it may be divided into two or more lobes and assume a feathery appearance. The stigma is covered with hair or with glandular papillae. It serves as the landing place grains for pollen during pollination.

Petals: Petals form the second whorl inner to the sepals. These are usually coloured, gaudy, or white in colour and scented and give a sweet smell. The value of a flower is due to the attractive colour of the petals. These attract the insects for pollination.

Sepals: These are the outermost part of the flower. These are leaf-like and green in colour. This is the outer covering of the flower and forms the outer whorl in a flower. The Calyx (sepals) enclose the inner parts of the flower when it is a bud. It is protective in function.

Pollen and Ovule: The function of pollen is to deliver male gametes (sperm) from the stamen of a plant to an ovule whereas the ovule when fertilized, well developed into a seed. It is a female reproductive cell.

Filament and Style:
The filament is a stalk-like structure that attaches and supports the flower and supports the anther which is the structure that produces pollens whereas the style transfers the male gametes of the pollen grains into the ovary.

Petal and Sepal:
Petals are colourful and attractive and help to attract insects for pollination whereas the main function of sepals is to provide protection to the growing bud.

Ovary and ovule:
1. The ovary is the female reproductive part of a flower and ovules are located inside the ovary.
2. Ovary after fertilization turns into a fruit whereas ovules turn into seeds of the fruit.

Endosperm: The endosperm is the nutritive tissue surrounding the embryo in a seed which provides nourishment to the developing embryo in seed during germination.

Cotyledons: The cotyledons provide food for the embryo during the first stages of germination in dicot plants. They act as leaves and perform photosynthesis in a seedling. In monocots, it absorbs the food from the endosperm and transports it to the embryo.

Embryo: In plants, an embryo is the baby plant present inside a seed which consists of a radicle, plumule, and cotyledons. It develops into a plant. In animals, the embryo is the early stage in the development of an organism. A fertilized egg develops into an embryo that grows into an adult plant or animal.