Labelled figure is given below:

The difference between autotrophs and heterotrophs are as follows

(a) Available in the plant: chlorophyll
(b) Available in the soil: water, minerals
(c) Available in the air: carbon dioxide
(d) Available during day: sunlight

Plants show two major modes of nutrition, i.e.
(i) Autotrophs are those which can synthesise their own food.
(ii) Heterotrophs are those which are dependent on other plants and animals for their food.
They are of following types:
(a) Parasites, e.g. Cuscuta
(b) Saprotrophs, e.g. fungi

Plants prepare their own food by the process of photosynthesis. Leaves of the plants have green pigment called chlorophyll, which helps them to capture the energy of the sunlight. The plants synthesise their food from carbon dioxide and water in the presence of sunlight. This process is called photosynthesis. The reaction for the process of photosynthesis can be shown as follows:

During photosynthesis, food is synthesised and oxygen is released in the process.

The presence of starch, a carbohydrate in leaves can be tested by iodine test. Iodine turns starch solution into blue-black colour. Pour few drops of dilute iodine solution on a boiled leaf. The leaf becomes blue-black in colour which proves the presence of starch in it.

The organisms need to take food to build their bodies, to grow, to repair damaged part of their bodies and to obtain the energy to carry out life processes. Food provide resistance to fight against diseases and protection from different infections.

(i) PARASITE, (ii) SAPROPHYTE, (iii) AUTOTROPH, (iv) SYMBIOSYS

The tiny pores present on the surface of the leaves are called stomata. They help in the exchange of the gases and to release excess of water by transpiration.

Autoprophs: (a) Green plants, (b) Algae
Heterotrophs: (a) Fungus, (b) Human.

Leaves contain chlorophyll which is essential for food preparation and is absent in other parts of plant.

The process of utilising nutrients like carbohydrates, proteins, fats, etc., to generate energy is called nutrition.

Leaves are referred to as food factories of plants. This is because, leaves synthesise food by the process of photosynthesies.

Guard cells help in controlling the opening and closing of stomata for gaseous exchange.

Stomata are the tiny pores present on the surface of leaves through which gaseous exchange takes place in plants.