2. Nutrition in Plants
All living organisms need food. Components of food are called
nutrition.
Examples of nutrition are-
1. Carbohydrates
2. Proteins
3. Fats
4. Vitamins
5. Minerals
3. Mode of Nutrition in plants
Plants are only the organisms who can synthesise food. They use water, carbon
dioxide and minerals for preparing their own food.
Nutrition: It is the mode of taking and utilizing food by body.
The nutrition help the organisms in-
1. Building bodies.
2. Being healthy.
3. Repairing their damaged parts of body.
4. Being energetic.
The organisms which prepare their food themselves, are called “Autotrophs”.
The organisms which does not prepare their food themselves and take the food
prepared by plants are called “heterotrophs”.
4. Food making process in plants
The plants prepare their food by the process of photosynthesis.
Leaves are the food factories of plants. The roots of the plants absorbs the
water and minerals present in soil and transport them to the leaves. Through
the tiny pores in plants called stomata, the carbon dioxide is taken from air.
There is a continuous path called vessels throughout the plants. Through these
vessels the raw material reach the leaves. A green pigment called chlorophyll is
present in leaves. It helps in capturing the sunlight.
(Photosynthesis= Photo: light; Synthesis: to combine.)
During photosynthesis, chlorophyll containing cells of leaves, in the presence of
sunlight, use carbon dioxide and water to synthesise carbohydrates. During this
process the oxygen is released.
6. Synthesis of plant food other than carbohydrates
The carbohydrates are made of carbon, hydrogen and
oxygen. These are used to synthesise other components of
food such as proteins and fats. But proteins are nitrogenous
substances which contain nitrogen. Plants cannot take
nitrogen in gaseous form. Soil has a bacteria called
Rhizobium that convert gaseous nitrogen into a usable form
and release it into the soil. These are absorbed by the plants
along with water. Plants can then synthesise proteins and
other vitamins.
7. Other Modes Of Nutrition In Plants
Some plants which do not have chlorophyll. They cannot
synthesise food. They use heterotrophic mode of
nutrition.
Types of heterotrophic plants-
1. Parasites
2. Insectivorous plants
3. Saprotrophs
8. Parasites
The plant which climb on other plant and take ready-made food
from the host plant is called parasite.
Examples of parasites-
1. Cuscuta (Amarbel)
2. Head lice
3. Tapeworms
4. Fleas
9. Insectivorous Plants
Insectivorous plants are plants that derive some or most of their
nutrients from trapping and consuming insects.
Examples of insectivorous plants-
1. Pitcher Plant
2. Venus Flytrap
3. Sundew
10. Saprotrophs
The organisms which take in nutrients from dead and decaying
matter is called saprotrophs.
Examples of saprotrophs-
1. Bacteria
2. Fungi
11. How Nutrients Are Replenished In Plants
Farmers spread manure or fertilisers in the fields. Fertilisers and
manures contain nutrients such as nitrogen, potassium,
phosphorous, etc. These nutrients need to be added from time to
time to enrich the soil. In this way the nutrients are replenished in
plants.