Archive | Essay

Stem is an aerial part of a plant and develops from the plumule of seeds. It develops upwards against the force of gravitation and towards the source of light. It possesses definite nodes and internodes. The growing point of the stem remains at its apex and is represented by terminal bud.

Soil is usually defined as any part of the earth’s crust in which plants root. Soil is composed of three types of constituents: (i) soil particles (ii) water and (iii) air.

Growth and multiplication of cells of a living organism are the basic necessities for its proper growth. The process of cell division is found same in all living organisms and the events are chiefly centre in the nucleus.

Despite the great diversity in the structure of cells, the basic structural plan is similar in all the cells. It can be expressed as generalized cells. A small speck of protoplasm that constitutes one cell is called pro­toplast. Protoplast or protoplasm of a cell can be differentiated in three essential parts, i.e.

It is swollen in the middle but tapers gradually towards the two ends, e.g., radish.

It consists of organic matter such as dung of cattle, dead leaves and twigs. It improves the texture of soil, provides food to the beneficial bacteria and increases the water-holding capacity of soil.

Plants belonging to this group are the simplest and most primitive ones. Their bodies are not differentiated into organs like root, stem and leaf. In fact, the body is an undifferentiated mass of cells known as thallus.

Dispersal of Fruits and Seeds the dispersal of fruits and seeds is the advantage of plants, as it enables them to flourish in a peaceful manner and find new localities where conditions are favorable for their growth.

The transference of the pollen from the anther to the receptive stigma, whether of the same flower or of a different flower, is known as pollination.

Flower is a modified shoot meant for reproduction. It arises as a bud in the axil of a specialized leaf called bract.

Most of the physiological activities and growth in plants are regulated by the action and interaction of some chemical substances called hormones. In plants, they are termed as phytohormones.

The energy stored in carbohydrate molecules dur­ing photosynthesis is released during cellular oxi­dation of carbohydrates into CO2 and H2O. This is called respiration.

Although literary meaning of photosynthesis is synthesis with the help of light, this term is usually applied to a very important vital process by which green plants synthesize organic matter in the presence of light.

Electromagnetic waves from a power source magnetron are absorbed by the food and food becomes hot at once.

Solar cooker works on solar energy. Solar cooker can directly utilize solar energy or can use deflected solar energy from a large concentration rays surface.

This group includes foods rich in carbohydrate, fat and protein. One gram of carbohydrate gives 4 calories.