- Food is the most necessary and fundamental thing for life.
- Minerals, vitamins and the other components required to live a life are all present in the food we eat.
- These components are necessary for all living beings either animals, humans and even plants.
- Yes, plants also require necessary nutrients to grow.
- Food is the basic requirement of all the living organism for living a life.
- Plants make their food themselves but animals cannot.
- Hence, animals depend directly or indirectly on the plant.
- Nutrition in plants is the study of the chemical elements and compounds necessary for the growth of a plant.
- Plant metabolism and their external supply.
- Proper nutrition is required for the healthy growth of a plant.
Modes of nutrition
- There are basically two main modes of nutrition.
- First, is Autotrophic – It is a mode of nutrition in which organisms make their food themselves with the given organic substance.
- The one i.e.plants who take their food through autotrophic mode of nutrition are referred as autotrophs.
- Plants exhibit autotrophic nutrition and are called primary producers.
- Second, one is Heterotrophic – Both animals and human beings are called heterotrophs, as they depend on plants for their food.
- The ones which cannot prepare their food themselves comes in the list of heterotrophs.
- And their mode of nutrition is heterotrophic.
- Photosynthesis is a process used by plants and to make their food.
- This is done by light energy (which comes from the sun) into chemical energy which is required for their growth.
- The food is stored in carbohydrate molecules, such as sugars, which are combined from carbon dioxide and water.
- Then, oxygen is also released as a waste product.
- Oxygen is released as a waste product by the plant the product which is of no use for them but for the living beings it is the necessity for their survival.
Process of photosynthesis
- Leaves are called the powerhouse of the plant because photosynthesis (the procedure of making food by the plants) is carried out by the leaves.
- Firstly, the water and minerals that are present in the soil are absorbed by the roots and transported to the leaves.
- The carbon dioxide which is present in the atmosphere is absorbed by ‘stomata’.
- Stomata are the tiny pores present all over the leaves through which carbon dioxide enters in the leaves they are guarded by ‘guard cells’.
- Water, minerals and the other necessary nutrients which are required for the process are transported from different parts of the plant with the help of ‘vessels’.
- Vessels are pipe like structures that form passage all over for the nutrients to be transported.
- Sunlight which is another important requirement in the process is absorbed in the form of light energy by the leaves with the help of ‘chlorophyll’.
- Chlorophyll is a green colour substance present in plants which helps them in the process of photosynthesis as well it also helps the plant to remain green basically, it is also responsible for the green colour of the plants.
- Since the synthesis(prepared) from carbon and water the process is called photosynthesis .
- Sunlight, carbon dioxide , water, minerals all these are required for the success of photosynthesis.
- During photosynthesis, cells of leaves containing chlorophyll in the presence of carbon dioxide prepares carbohydrates.
- Carbohydrate is the food prepared by the plants.
Equationally, it can be represented as:-
Carbon dioxide + water + sunlight + chlorophyll = Carbohydrates + oxygen
- Oxygen is released as the result of photosynthesis which is a necessity for living by other organisms.
Absorption of other nutrients
- Plants also require other nutrients proteins and fats other than carbohydrates.
- Proteins are nitrogenous substances i.e., substance which contains nitrogen.
- Although nitrogen is present in abundance in the atmosphere, plants cannot absorb atmospheric nitrogen.
- Plant gets nitrogen from soil.
- There is a specific bacteria present in the soil .
- The bacteria namely rhizobium holds the capability to convert the nitrogen present in the air to the nitrogen directly used by the plants
- Plants absorb nitrogen along with water and other minerals through roots.
- In this way plants get fulfillment of nitrogen along with other nutrients.
- After the fulfillment of all nutrients plants synthesise proteins and fats.
Other modes of nutrition
- Some plants lack chlorophyll due to which they are unable to make their own food.
- These types of plant use heterotrophic mode of nutrition.
- Which means they are dependent for food on others.
- For example parasitic plants like sandalwood trees, red bartsia, loranthus etc. use heterotrophic mode of nutrition.
- They absorb all the required from the plant they climb upon.
- The plant from which they absorb all the required nutrients is referred to as a host.
Re-fillment of nutrients in the soil
- Nutrients in the soil which are required by the plant are replenished by adding fertilisers and manures.
- Fertilisers and manures contain plant nutrients and minerals like nitrogen, phosphorus and potassium.
- Also some specific kind of bacteria helps in converting nitrogen into usable form.
- As ,we studied earlier about the bacteria adding nitrogen in the soil .
- Which is also used or which is also taken up as food by the plants.
- And then, from the soil it is transported to the plant.
In this chapter we have learned about different ways through which plants make their food and gives out the most necessary thing required by all of us which is oxygen.