NUTRITION IN PLANTS [CLASS-7]

SCIENCE                  CLASS-7

       

NUTRITION IN PLANTS

1. NUTRIENTS

Carbohydrates, Proteins, Fats, Vitamins and Minerals are called nutrients.

2. FOODS

The digestible organic substances containing nutrients are called foods.

3.NEED OF FOOD

For a living organism, food provides energy for growth and maintenance the body.

4.NUTRITION

The mode of taking food by an organism and its utilisation by the body is called nutrition.

5.MODE OF NUTRITION IN PLANTS

A. AUTOTROPHIC NUTRITION :- By all green leafy plants
B. HETEROTROPHIC NUTRITION :- By Cascuta(Amarbel) and Pitcher Plants
C. SAPROTROPHIC NUTRITION :- By Mashroom ( Fungi)

6. AUTOTROPHIC NUTRITION

• The mode of nutrition in which organisms make food themselves from simple inorganic substances is called autotrophic nutrition [auto=self; trophos = nourishment ] and the organisms are called autotrophs.


• All green plants are autotrophs.


• Heterotrophs:- Animals and most other organisms take in food prepared by plants,are called heterotrophs.

7. PHOTOSYNTHESIS

• Food factories of plants - Leaves
• Photosynthesis :- This is the food making process in green plants.
• Necessary things used in photosynthesis :- (i)water (ii) carbon dioxide (iii)sunlight (iv)chlorophyll
• Chlorophyll:- It is the green pigment. It helps leaves to capture sunlight energy. It makes the leaves green.
• Representation of photosynthesis as an equation
  
  
  




• Main products of photosynthesis:- (i)Glucose (ii) Oxygen gas


• Site of photosynthesis - Leaves , Stems
• Cellular site of photosynthesis - Chloroplast
• Photosynthesis in various coloured plants:- In croton like plants, another colours found in large amount, mask the green colour.So, these plants also perform photosynthesis.