LESSON 1

NUTRITION IN

PLANTS

Food is required by all organisms :-

* For getting energy.

* Growth ,development and repair.

* Protect themselves from diseases

Nutrients:- The components of food that are carbohydrates,protiens,vitamins and minerals are called nutrients.

Nutrition:-The process of taking food and their utilisation in the body is called Nutrition.

Modes of nutrition

There are two modes of nutrition in living

organisms:-

1.Autotrophic Nutrition:-In this type of nutrition

living organisms can prepare their own food.

2.Hetrotrophic Nutrition:-In this type of nutrition

organisms get the food directly or indirectly from

plants.

PHOTOSYNTHESIS

Photosynthesis is the process in which plant

prepare their own food by using sunlight water and carbon dioxide and chlorophyll Photosynthesis occurs in leaves.

Requirements of photosynthesis :-

1.Sunlight is obtained from sun

2.Carbon dioxide is taken from air

through stomata.

3.Water is absorbed by roots and

transported to the leaves

4. Chlorophyll is the green pigment that traps sunlight.

PRODUCTS OF PHOTOSYNTHESIS

1.Carbohydrate which is converted to starch.

2.Oxygen is released.

Equation for photosynthesis:-

Carbon dioxide + water carbohydrate + oxygen

SYNTHESIS OF PROTIENS

Protiens are nitrogenous substances which contain nitrogen. Although nitrogen is present in abundance in atmosphere but plants cannot absorb atmospheric nitrogen. Plants get nitrogen from soil. Certain bacteria called Rhizobium are present in soil which are able to convert gaseous nitrogen into usable form and release it in the soil. Plants absorb these soluble forms of nitrogen along with water through roots.

Farmers add nitrogenous fertilizers to the soil to fulfill the need of nitrogen.

After the fulfillment of all nutrients, plants synthesis proteins and fats.

OTHER MODE OF NUTRITION IN PLANTS:-

1. Parasitic mode of nutrition-

Parasitic plants: These plants do not have

Chlorophyll and they cannot prepare their own

food. They derive their food from other plants

called host.This mode of nutrition is called

parasitic mode of nutrition. Eg. Cuscuta

(Amarbel)

INSECTIVOROUS PLANTS

These plants feed on other organisms like insects. Eg. Pitcher

plant

The leaf of a pitcher plant is modified into a pitcher. The apex of

the leaf is modified into lid which can open and close. There

are hairs in the pitcher directed downwards.

When an insect sits on the pitcher, the lid closes and the insect in

trapped and digested by digested by digestive juices.

2. SAPROTROPHIC MODE OF NUTRITION:

The mode of nutrition in which some plants derive their food from

dead and decaying matter is called saprotrophic mode of

nutrition. These plants are called saprotrophs.

Eg. Mushroom, Bread mould.

They produce digestive juices on the dead and decaying organic

matter and convert them into solution and then absorbs it.

FAQS

1.What are the components of food?

2.What is nutrition?

3. What is autotrophic mode of nutrition?

4. What is heterotrophic mode of nutrition?

5. What are saprotrophs? Give two examples.

6. Define photosynthesis?

7. List the essentials needed for photosynthesis?

8. Why are leaves green in colour?

9. What are the final products of photosynthesis?

10. What is stomata and what is its function?

11. What is the ultimate source of energy?

12. In what form do the plants absorb nitrogen?

13. Why do farmers add nitrogenous fertilisers to the soil?

14. Name the microorganism that converts atmospheric nitrogen to soluble forms.

15. What do you understand by parasitic plants?

16. Give an examples of parasitic plant.

17. What is the mode of nutrition in non green plants?

18. What do you understand by host?

19.What do you understand by insectivorous plants? Give some examples.

20. How does pitcher plant trap the insects? Explain with diagram.

21. What do you mean by saprotrophic mode of nutrition?

22. Give two examples of saprotrophs.