Class VII – Science

Chapter 1: Nutrition in Plants

I. Fill in the blanks

1. The process of intake of food and its proper utilization by the body is called nutrition.
2. Two modes of nutrition in plants are autotrophic and heterotrophic.
3. The mode of nutrition in which an organism makes its own food from simple substances like carbon dioxide, water, and minerals present in the surroundings is called autotrophic.
4. All the green plants and some bacteria prepare their own food by autotrophic mode of nutrition.
5. The leaves of a plant are green because they contain tiny green-colored bodies called chloroplasts that contain a green pigment called chlorophyll.
6. The chloroplast uses sunlight to prepare food from carbon dioxide and water.
7. The process by which green plants make their own food from carbon dioxide and water in the presence of sunlight and chlorophyll is called photosynthesis.
8. Complete the photosynthesis reaction: \[ \text{Carbon dioxide} + \text{water} \xrightarrow{\text{A}} \text{C} + \text{D} \] – A: Chlorophyll – B: Sunlight – C: Glucose – D: Oxygen
9. The food prepared by the green leaves of a plant is in the form of a simple carbohydrate called glucose.
10. The extra glucose is changed into a complex carbohydrate called starch, which is also the reserve food material of a plant.
11. The conditions necessary for photosynthesis are sunlight, chlorophyll, carbon dioxide, and water.
12. The chemical used for decolorizing a leaf is alcohol.
13. The process of decolorizing a leaf is known as bleaching.
14. The green color of the plants is due to the presence of the pigment called chlorophyll.
15. In desert plants, like cactus, the leaves are modified into spines to reduce water loss by transpiration.
16. Tiny pores called stomata present on the underside of the leaves, which are surrounded by guard cells.
17. The guard cells control the opening and closing of stomata.
18. Water and minerals are absorbed by the roots of the plants from the soil.
19. Xylem is a tube-like structure found in roots, stem, branches, and leaves that transport water and minerals to the plant.
20. Food is stored in plants in the form of starch.
21. Proteins are substances that contain nitrogen.
22. Plants need nitrogen in a soluble form.
23. Soil has certain bacteria, called nitrogen-fixing bacteria that take atmospheric nitrogen and convert it into compounds like nitrates.
24. Certain plants, like sunflower and soybean, convert glucose into starch and store them in their seeds.
25. The word heterotrophic means feeding on others.
26. The organisms that obtain food prepared by the green plants directly or indirectly are called heterotrophic type of nutrition.
27. The parasitic is a type of nutrition in which some plants live in or on the body of other living organisms.
28. The mode of nutrition of getting nutrients from dead and organic matter of plants and animals is called saprotrophic. Plants that use saprotrophic mode of nutrition are called saprophytes.
29. A lichen is composed of two distinct organisms, algae and fungus that live and work together.
30. Parasitic plants live on other plants called hosts and depend on them for nutrition.
31. The association in which two different types of work together for their mutual benefit is called symbiosis.
32. Rhizobium bacteria live in the nodules of the roots of leguminous plants and provide them nitrogen in a soluble form.
33. Some plants feed on insects to fulfill their nitrogen requirements. These insect-eating plants are called insectivorous.
34. In a pitcher plant, the leaves are modified to form a pitcher-like structure, and the lid is modified into a lid that closes and opens the mouth of the pitchers.
35. Manure and fertilizers are used to replenish the nutrients in the soil.