Nutrition || Nutrition in Plants || Autotrophic Nutrition & Heterotrophic Nutrition

Nutrition in Plants

People eat meat and think they will become as strong as an OX. Dear people, you forgot one thing: that the ox eats Grass !!

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“HEALTH is the first form of WEALTH”

Nutrition || Nutrition in Plants || Autotrophic Nutrition & Heterotrophic Nutrition pdf

What is nutrition?

Nutrition is the biochemical and physiological process by which an organism use food to support its life. Plants are also living things; they have cells and tissues, they also grow in size and girth and most importantly they are the producers of the ecosystem. So they also need some form of energy to grow. So, in order to synthesize food, they also require nutrients.

Nutrition in plants:

   So we can say, plant nutrition is the study of chemical elements and compounds necessary for plant growth, plant metabolism and their external supply. In its absence the plant isn’t able to complete it’s normal life cycle.

    Plants include seventeen Essential nutrient elements such as carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from soil.

 Plants obtain two types of mineral nutrients from their growing medium :

 1. The macronutrients

2. The micronutrients

1. The macronutrients:

    These elements stay beneath the soil as salts. The macronutrients are taken up in large quantities; hydrogen, nitrogen, oxygen and carbon contribute to over 95% of a plants entire biomass on a dry matter weight basis.

 The macronutrients are: nitrogen (N), Hydrogen, (H), Phosphorus (P), potassium (K), Calcium (Ca), Sulphur (S), Magnesium (Mg), Carbon (C), Oxygen (O).

2. The Micronutrients (Trace minerals):

  Micronutrients are present in plant tissues. The micronutrients are:

 iron(Fe), Boron (B), Chlorine (Cl), Manganese (Mn), Zinc(Zn), Copper (Cu), Molybdenum (Mo), Nickel (Ni).

Modes of nutrition:

  Plants produce their food by taking raw materials from the surroundings; such as minerals, carbon dioxide, water and sunlight. There are two modes of nutrition:

1. Autotrophic nutrition

2. Heterotrophic nutrition

Autotrophic nutrition:

 If we break the word ‘autotrophic’ then we can find ‘auto’ which means ‘self’ and ‘trophic’ which means ‘nutrition’ . The two words constitute a whole meaning of ” self_nutrition”. Hence autotrophic nutrition is a process in which green plants produce their food from simple inorganic materials such as water, carbon dioxide and mineral salts in the presence of sunlight.

Types of autotrophic nutrition:

  According to kind of energy sources used, autotrophic nutrition can be of two kinds:

1. Photoautotrophic (where sunlight is the only source of energy)

2. Chemoautotrophic (where chemicals are the energy sources


CO2 + H2O    _   C6H12O6



The method by which plants produce their own food is called photosynthesis. This process occurs mostly in the leaves which is called “the kitchen of the plant”.

Photosynthesis process:

   Photosynthesis is a method to transform solar energy into chemical energy to produce starch. Different parts of plants play different roles to complete the photosynthesis process.


         They are the food factory of the plant. The leaves contain chlorophyll which is found in chloroplast; plays a major role, capturing the energy from sunlight to prepare food.


     It is present in the lower epidermis of the leaf which uses carbon dioxide (CO2) from air.


      They absorb minerals and water from soil and carry it to different parts of the plant. Food production is primarily carried out in leaves. Water and minerals are absorbed by roots from soil; carbon dioxide reaches leaves through stomata. Chlorophyll captures energy from sunlight to prepare food. The whole process happens in the presence of sunlight, hence called photosynthesis. During the process CO2 is used in the presence of sunlight to produce carbohydrates and oxygen. Oxygen is one of the main components released during photosynthesis.

Condition necessary for photosynthesis:

1. Sunlight

2. Water

3. Carbon dioxide

4. Chlorophyll

Purpose of photosynthesis:

 For plants, photosynthesis helps to produce glucose to be able to produce energy to perform different functions in plants. Plants also require energy to make other biological and biochemical methods to enable it to multiply.

Heterotrophic nutrition in plants:

 The plants which don’t contain chlorophyll depend on other plants for their nutrition. These modes are called heterotrophic nutrition. These plants can be called parasites.

   There are four types of heterotrophic plants which are classified on the basis of their mode of nutrition.

1. Parasitic

2. Insectivorous

3. Saprophytic

4. Symbiotic

1. Parasitic plants:

 Some heterotrophic plants depend on other plants and animals for nutrition. Such plants are known as parasitic plants.

Ex: Cuscuta, Cassytha

2. Insectivorous or carnivorous plants:

 Some plants have the structure to trap the insects and digest them by the secretion of digestive juice and absorb nutrients from them. Those types of plants are known as carnivorous plants.

 Ex: pitcher plants, Venus flytrap

3. Saprophytic plants:

 The saprophytic plants derive nutrition from dead and decaying plants and animals.

Ex: mushroom, moulds

4. Symbiotic plants:

When two different plants belong to two different categories but show a close association, and are beneficial for each other is known as symbiotics.

 Ex: The association of fungi and trees.

3 thoughts on “Nutrition || Nutrition in Plants || Autotrophic Nutrition & Heterotrophic Nutrition”

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