NCERT 7th Class (CBSE) Science: Nutrition in Plants

Question: What is nutrition?

Answer: The process of taking in food by an organism and its utilization by the body is called nutrition. There are two types of nutrition:

1. The mode of  nutrition in which organisms make food  themselves from simple substances is called autotrophic nutrition. For example plants.
2. The mode of nutrition in which organisms take in ready made food prepared by the plants called heterotrophic nutrition. For example animals

Question: What are ‘stomata’? Where are thy normally found?

Answer:  Leaves take in carbon dioxide from the air through tiny poses called stomata. These poses are located on the underside of the leaves.

Question: Write down the chemical equation for manufacture of food in green plants.

Answer:  Carbon dioxide+Water Chlorophil / sunlite Glucose+Oxygen.

Question: What factors are essential  for photosynthesis to take place?

Answer: The factors that are essential for photosynthesis are water and chlorophyll, Carbon dioxide, sunlight.

Questiona: How does an insectivorus plant absorb nutrients from an insect trapped by it?

Answer: An insectivorus plant absorb nutrients from an insect by the calls of the plant secrete digestive juices to digest the insect.

Question: Why are Nitrogenous fertilizers not added in soil in which leguminous plants are grown?

Answer: Nitrogenous fertilizers are not added in soil in which leguminous plants are grown because a bacteria Rhizobium can take atmospheric Nitrogen  and convert it into a soluble form that the plants can absorb.

Question: Differentiate between Autotrophs and Heterotrophs, giving two examples of each.

Answer: Difference between autotrophs and heterotrophs is as follows: