Science Class 7 – Chapter 1 –Nutrition in Plants- NCERT Exercise Solution (Question-Answer) is provided below. Total 13 Questions are in this NCERT Exercise, all are solved here.
Q1. Why do organism take food?
Answer- The organisms require energy for their life process. Food plays an important role for purposes such as-
Food gives us resistance to fight against disease and protect us from infections
Maintain bodily function
We need food for replacement and repairing damaged parts of body.
In plants , they prepare their own food and acquire nutrients from abiotic components like :- soil , air , water and sunlight
Animals also take food to acquire nutrients and energy.
Q2. Distinguish between a parasite and saprotrophs .
They acquire nutrients from dead and decaying matter .
They acquire nutrients from living organism.
They live on dead and decaying stuff.
They mostly live on or in the host
They do not feed on a living organism
The organism on which it feed is called host
Q3. How would you test the presence of starch in leaves?
Answer- The presence of starch in leaves can be tested by the iodine test. We have to take two potted plants of the same kind. We will keep one pot in a darkroom and other pot in sunlight for 72 hours. After 3-4 days, we will perform the iodine test on the leaves of the plant. Put the iodine solution on the leaf. We will observe some blue-black colour on leaves of the plant which kept in sunlight that indicates the presence of starch. But, we don’t observe blue-black colour on leaves of the plant which kept in the darkroom that indicates the absence of the starch.
Q4. Give a brief description of the presence of the synthesis of food in green plants.
Answer- In the green plant, the synthesis of food occurs by a process called Photosynthesis. Plants use a simple chemical substance like carbon dioxide, water and minerals for the synthesis of food.
During photosynthesis, chlorophyll-containing cells of leaves, in the presence of sunlight, use carbon dioxide and water to synthesis carbohydrates.
This process can be represented by an equation-
Carbon dioxide + water ➜carbohydrates + oxygen
in presence of sunlight and chlorophyll.
During this process, oxygen is liberated and the formed carbohydrates are stored in the form of starch.
Q5. Show with the help of sketch that plants are the ultimate source of food.