Solutions 1. Nutrition in Plants - Additional long-Answered Questions | Class 7 Science - Toppers Study

1. Nutrition in Plants

Ques1:- Give a brief description of the process of synthesis of food in green plants.

Ans:- The process of synthesis of food in green plants is known as photosynthesis. In which green plants take CO2 and water as a raw material. This process occurs in presence of chlorophyll which is a green pigment. Plants store synthesised food in leaves. 

Ques2:- What are insectivorous plants?

Ans:- The insect is digested by the digestive juices secreted in the pitcher. Such insect-eating plants are called insectivorous plants.

Ques3:- From where do the plants obtain nitrogen?
Ans:- Soil has certain bacteria that convert gaseous nitrogen into a usable form and release it into the soil. These soluble forms are absorbed by the plants along with water.

Ques4:- What is so special about the leaves that they can synthesis food but other parts of the plant cannot?
Ans:- Because the leaves have a green pigment called chlorophyll.

Ques5:- What is photosynthesis?
Ans:- The process by which green plants make their food from water and carbon dioxide in presence pf sunlight is called photosynthesis.

Ques6:- What is Saprotrophic mode of nutrition?

Ans:- The mode of nutrition in which the organisms take in nutrients in solution form from dead and decaying matter is called Saprotrophic mode of nutrition.

Ques7:- What is autotrophs?
Ans:- Organisms that can make their own food are called autotrophs or producers. 
For ex. Green plants. 

Ques8:- How would you test the presence of starch in leaves?

Ans:- When iodine comes in contact with starch, a dark blue colour appears. Testing the presence of starch in leaves, when we dropped some solution of iodine on leaves they give dark blue colour. Thus we can say there is starch in leaves. 

Ques9:- Write the differences between a parasite and a saprotroph.

Ans:- 

Parasite :- 

(i) It gets nutrients from host on which they live.

(ii) It lives on or in the host.

(iii) Ex: Cuscuta 

Saprotroph :-

(i) It gets nutrient from dead and decaying matter.

(ii) It lives on dead or decaying stuff.

(iii) Ex: Bacteria and fungi.

Ques10:- Why do organisms take food?

Ans:- Organisms need food to

(i) Get energy to do work.

(ii) Build up body .

(iii) Repair damages in the body.

(iv) Maintain the functions of the body.