Nutrition in Plants

Exercise

1. Why do organisms take food?

The organisms need to take food to grow, to repair damaged part of their cells and to obtain the energy to carry out life processes. Food provide resistance to fight against diseases and protection from different infections.

2. Distinguish between a parasite and a saprotroph.

ParasiteSaprotroph
It drives nutrients from living organisms.It drives nutrients from dead and decaying organism.
It mostly lives on or on the host.They live on dead and decaying stuff
Example: CuscutaExample: Fungi

3. How would you test the presence of starch in leaves?

Take 2 potted plants of the kind. Keep one pot in the sunlight another in the dark room for 3 days. Perform the iodine test for the both plant leaves.

 When starch comes in contact with iodine solution it gives a dark blue colour. When we added a few drops of iodine solution on the leaves dark blue colour appears, then it will confirm the presence of dtarch in the leaves.

4. Give a brief description of the process of synthesis of food in green plants.

Green plants prepare their food in the process called Photosynthesis.

During the photosynthesis, chlorophyll containing cells of leaves, in the presence of sunlight, use carbon dioxide and water to synthesise carbohydrates. The process can be represented in an equation:

    5. Show with the help of a sketch that plants are the ultimate source of food.

During the process oxygen is released. The presence of starch in leaves indicates the occurrence of photosynthesis. Starch is also a carbohydrate.

6. Fill in the blanks:

(a) Green plants are called autotrophs since they synthesise

their own food.

(b) The food synthesised by plants is stored as starch.

(c) In photosynthesis solar energy is absorbed by the pigment called

chlorophyll.

(d) During photosynthesis plants take in carbon dioxide and

release oxygen gas.

7. Name the following:

A parasitic plant with yellow, slender and branched stem.

Cuscuta

(ii) A plant that is partially autotrophic.

Pitcher plant

(iii) The pores through which leaves exchange gases.

Stomata

8. Tick the correct answer:

(a) Cuscuta is an example of:

(i) autotroph (ii) parasite (iii) saprotroph (iv) host

(b) The plant which traps and feeds on insects is:

(i) Cuscuta (ii) china rose (iii) pitcher plant (iv) rose

9. Match the items given in Column I with those in Column II:

Column IColumn II  
ChlorophyllRhizobium
NitrogenHeterotrophs
CuscutaPitcher plant
AnimalsLeaf
InsectsParasite

10. Mark ‘T’ if the statement is true and ‘F’ if it is false:

(i) Carbon dioxide is released during photosynthesis. (T/F): False

(ii) Plants which synthesise their food are called saprotrophs. (T/F):False

(iii) The product of photosynthesis is not a protein. (T/F): True

(iv) Solar energy is converted into chemical energy during

photosynthesis. (T/F): True

11. Choose the correct option from the following:

Which part of the plant takes in carbon dioxide from the air for

photosynthesis?

(i) Root hair (ii) Stomata (iii) Leaf veins (iv) Petals

12. Choose the correct option from the following:

Plants take carbon dioxide from the atmosphere mainly through their:

  • roots (ii) stem (iii) flowers (iv) leaves

13. Why do farmers grow many fruits and vegetable crops inside large green

houses? What are the advantages to the farmers?

It protects crops from external climatic conduction and to provide suitable temperature for the growth of crop.

Advantages:

  1. It protects crop from diseases.
  2. It protects the crop from wind
  3. It protects the crop from rodents