Ch_1 Nutrition in Plants

Q1. Why do organisms need to take food?

Ans. 

Food is needed by all organisms for many purposes:(a) The main function of food is to help in growth.(b) Food provides energy for movements such as running, walking or raising our arm.(c) Food is also needed for replacement and repairing damaged parts of body.(d) Food gives us resistance to fight against diseases and protects us from infections

Q3. How would you test the presence of starch in leaves?

Ans. 

The presence of starch in leaves can be tested by Iodine test. When we remove chlorophyll from leaf by boiling it in alcohol and then put 2 drops of iodine solution, its colour change to blue indicates the presence of starch.

Q4. Give a brief description of the process of synthesis of food in green plants.

Ans. 

The green plants have chlorophyll in the leaves. The leaves use C02 and water to make food in presence of sunlight.

Q5. Show with the help of a sketch that the plants are the ultimate source of food.

Q6. Fill in the blanks:

(a) Green plants are called _________ since they synthesise their own food.

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

(c) In photosynthesis solar energy is captured by the pigment called __________ .

(d) During photosynthesis plants take in _________ and release ___________ .

Ans. 

(a) autotrophs

(b) starch

(c) chlorophyll

(d) carbon dioxide, oxygen

Q7. Name the following:

(i) A parasitic plant with yellow, slender and tubular stem.

(ii) A plant that has both autotrophic and heterotrophic mode of nutrition.

(iii) The pores through which leaves exchange gases.

Ans. 

(i) cuscuta

(ii) Insectivorous plant

(iii) Stomata

Q8. Tick the correct answer:

(a) Amarbel is an example of:

(i) Autotroph           (ii) Parasite

(iii) Saprotroph          (iv) Host

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

(a) Cuscuta                 (ii) China rose

(iii) Pitcher plant       (iv) Rose

Ans.

(a) - (ii) Parasite

(b) - (iii) Pitcher plant