Class 7 – Chapter -1 – Nutrition in Plants
Nutrition in plants for class 7 NCERT solutions for class 7 science chapter 1 question answer
Why do organisms need to take food?
All organisms require food and use it to obtain energy for body growth and maintenance.
Distinguish between a parasite and a saprotroph.
Parasites feed on living organisms while saprotroph feed on dead and decaying matter
Example of parasites are –Amarbel
Example of saprotrophs are – fungi
How would you test the presence of starch in leaves?
The presence of starch in leaves can be determined using an iodine test. Iodine changes the colour of the starch solution to a blue-black. A few drops of diluted iodine solution should be applied to the boiled leaf. The presence of starch causes the leaf to turn blue-black.
Give a brief description of the process of synthesis of food in green plants.
- Leaves are also known as food factories of plants.
- Carbon dioxide from the atmosphere is taken through the tiny pores on the surface of the leaves called stomata.
- Chlorophyll is a green pigment found in the leaves.
- It helps leaves in capturing sunlight energy.
- This energy is used to create food by combining carbon dioxide and water.
- Photosynthesis is the process by which food is synthesized in the presence of sunlight.
Fill in the blanks:
- Green plants are called _________________ since they synthesize their own food.
- The food synthesized by the plants is stored as _________________.
- In photosynthesis, solar energy is captured by the pigment called…….
- During photosynthesis plants take in ________________ and………
- Chlorophyll [green pigment]
- Carbon dioxide , oxygen
Name the following:
(i) A parasitic plant with the yellow, slender, and tubular stem.
(ii) A plant that has both autotrophic and heterotrophic modes of nutrition.
(iii) The pores through which leaves exchange gases.
Tick the correct answer:
(a) Amarbel is an example of:
Correct answer – parasite
(b) The plant which traps and feeds on insects is: