We will discuss about the plant and its leaves. Leaves are one of the main parts of the plant. Leaves of a plant have its own function. A plant bears so many leaves. Mostly leaves are green in color. The leaves are attached to the twigs and branches by the stalks.
Leaves of different plants vary in shape and size but their basic structure is the same. In a leaf there is a network of veins. The main vein starts from the stalk and goes up to the end of the leaf, running through the middle of it. There are many side veins emerging from the main vein.
The leaf is covered with a waxy covering called as cuticle on both surfaces but in the lower area of the flat leaf there are invisible openings called stomata. Stomata can be seen with the help of a microscope.
A leaf prepares food for the plant. Food for plants is prepared by green leaves through the process of photosynthesis.
Water, mixed with minerals reaches the leaves from the soil through the different parts i.e. roots, stem, branches and twigs. The sunlight reaches the leaves through their skin and is absorbed by the chlorophyll. Through the stomata the leaves get air containing carbon-dioxide from the atmosphere. Using the energy of sunlight absorbed by the chlorophyll leaves change water and carbon dioxide into a kind of sugar (i.e. carbohydrates) and oxygen is given out. Some of the sugar is used by the plant as food to grow. Some of the sugar is changed into starch. The rest of the sugar and the starch are stored in different parts of the plant.
The food is stored in roots, for example as in carrot.
The food is stored in grains, for example as in wheat and gram.
The food is stored in stem, for example as in sugarcane.
The food is stored in fruits and vegetables, for example as in papaya.
The green leaves are called the food factories of the plant as food is prepared there.
The process of making food by the leaves of a plant in presence of sunlight absorbed by chlorophyll is called photosynthesis.
The process of photosynthesis may be represented as-
Generally we know leaves are green in color but some plants like cactus or mushroom do not have green leaves. Cactus makes food in its green stem and mushroom gets its food from decaying plants.