What is leaf? Full explanation.

The leaf is a thin, broad, flat and green part of a plant which is attached to the stem (or branch). plural of leaf is leaves. A plant has a large number of leaves. Leaves of different plants have differe shapes and sizes, but all of them have the same basic structure.

A leaf consists mainly of two parts: lamina and petiole (see Figure 8). Lamina is commonly ke o as leaf blade and petiole is commonly known as leaf stalk. The broad, green part of the leaf is called lan th The thin stalk with which leaf is attached to the stem (or branch) is called 'petiole. There is a mid tr (main vein) in the centre of lamina (or leaf blade). A large number of veins spread out from the mid Rib to all the parts of the leaf. The mid-rib and veins consist of bundles of tiny tubes some of which carry water (and dissolved minerals) into the leaf, and others carry away the food from the leaf.

There are minute pores on the surface of a leaf (which are called stomata). Stomata are so small that we cannot see them with naked eyes. The stomata allow the gases to move in and out of the leaf. They also allow excess water vapour to go out of the leaf. The leaves of plants contain a green coloured pigment called 'chlorophyll'. Chlorophyll imparts green colour to the leaves. Chlorophyll can absorb (or trap) energy from sunlight.

The leaves of plants have three main functions:

(1) The leaves make food for the plant (by photosynthesis).

(ii) The leaves get rid of excess water from the plant(through transpiration).

(iii) The leaves carry out the process of respiration in plants (which is the production of energy from food).

What are life process?

WHAT ARE LIFE PROCESSES? The maintenance functions of living organisms must go on even when they are not doing anything particular. Even when we are just sitting in class even if we are just asleep, this maintenance job has to go on The processes which together perform this maintenance job an We processes . Since these maintenance processes are needed to prevent damage and break-down energy is needed for them. This energy comes from outside the body of the mdhadual organism. So there must be a process to transfer a source of energy from outside the body of the organism which we call food, to the inside, a process we commonly call nutrition If the body size of the organisins is to grow, additional raw material wit also be needed from outside. Since life on earth depends on carbon- based molecules most of these food sources are also carbon-based Depending on the complexity of these carbon sources, different organisms can then use different kinds of nutritional processes The outside sourc...

Nutrition in human being?

Nutrition in Human Beings The alimentary canal is basically a long tube extending from the mouth to the anus. we can see that the tube has different parts. Various regions are specialised to perform different functions. What happens to the food once it enters our body? We shall discuss this process here. We eat various types of food which has to pass through the same digestive tract, Naturally the food has to be processed to generate particles which are small and of the same texture. This is achieved by crushing the food with our teeth, Since the lining of the canal is soft, the food is also wetted to make its passage smooth. When we eat something we like, our mouth waters. This is actually not only water..but a fluid called saliva secreted by the salivary glands. Another aspect of the food we ingest is its complex nature. If it is to be absorbed from the alimentary canal, it has to be broken into smaller molecules. This is done with the help of biological catalysts called enzyme...

Adaptation in lion & adaptation in deer

A large area of land covered mainly with trees and plants is called alaust And a large area of grass covered land used for grazing is called grassland There are few trees or places for animals to hide gland habitats. Due to this speal is important for the animals which live in grassland habitats (so they can nits away from their enemies) For most common purposes, however, the wrous forest and and are used in the same sense. The forest (or grassland) is a habitat Many animals such as lon som elephants deer, en live in forest habitats. There are many features of a lion, a deck, other animals and plant which help them to survive in the forest habitat. The adaptations in lion and deer to the forest habitat are described below. Adaptation of lion The lion is a camivorous animal which eats only the meat (or flesh) of oder animals. The lion lives in a forest habitat The adapted to the forest habitat in the following ways: 1.The lion is a strong, fast and agile animal which can hunt and ...

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