Autotrophs: Autotrophs are the green plants which synthesise their food themselves by the process of photosynthesis.

Photosynthesis: the process of preparation of own food by the Green plants with the help of chlorophyll (found in green plants), carbon dioxide and water taken from the environment in presence of sunlight is known as photosynthesis.

Plants use simple chemical substances like carbon dioxide, water and minerals for the synthesis of food.

Chlorophyll and sunlight are the essential requirements for photosynthesis.

Complex chemical substances such as carbohydrates are the products of photosynthesis.

Solar energy is stored in the form of food in the leaves with the help of chlorophyll.

Oxygen is produced during photosynthesis.

Oxygen released in photosynthesis is utilised by living organisms for their survival.

Fungi derive nutrition from dead, decaying matter.

They are saprotrophs.

Plants like Cuscuta are parasites.

They take food from the host plant.

A few plants and all animals are dependent on others for their nutrition and are called heterotrophs.

Parasitic: Organisms that live on the body of other organisms. All parasitic plants feed on other plants as either:

Partial Parasites: Obtain some of their nutrition from the host,

Example: Painted cup

Total Parasites: Dependent completely on the host for nutrition.

Example: Mistletoe.

Nutrition in plants

Saprophytic: Organisms that obtain nutrition from dead and decaying plant and animal matter.

Mushrooms, moulds and certain types of fungi and bacteria.

Insectivorous Plants: Green plants which obtain their nourishment partly from soil and atmosphere and partly from small insects.

Example: pitcher plant, bladderwort, and venus fly trap.

Symbiosis: Mode of nutrition in which two different individuals associate with each other to fulfil their requirement of food.

Lichens found on tree trunks is the association between algae and fungus.

Algae obtains water from fungus and it in turn obtains food from algae.