Fill in the blanks:
(a) Green plants are called _________________ since they synthesise their own food.
(b) The food synthesised by the plants is stored as _________________.
(c) In photosynthesis solar energy is captured by the pigment called ___________.
(d) During photosynthesis plants take in ______________________ and release __________________.
(a) Autotrophs
The mode of nutrition in which organisms make their food themselves from simple substances is called autotrophic nutrition. Hence, the plants that makes their own food are called autotrophs. There is a green pigment that are found in leaves of plants are called chlorophyll, which helps plants to capture sunlight and this energy is used to synthsis food from carbon dioxide and water.
(b) Starch
During photosynthesis oxygen gets released and the food is stored in leaves. Starch is a carbohydrate. The presence of starch in leaves indicates the occurrence of photosynthesis which can also be prooved by the iodine test.
(c) Chlorophyll
The green pigment present in the surface of the leaves is known as chlorophyll. It helps leaves to capture to the sunlight which can then be used to prepare food.
(d) CO2 , O2
During photosynthesis plants take CO2 and release O2 gas.
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
Sketch the cross section of soil and label the various layers.
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human body
Down
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
Sketch the reproductive parts of a flower.
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.
Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.
Describe how crystals of copper sulphate are prepared.
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus
Write one similarity and one difference between the nutrition in amoeba and human beings.
Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
What makes the blood look red?
Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
Why should we worry about the conditions and issues related to forests far from us?
Explain the relationship between sanitation and disease.
What is meant by the following terms?
(i) Rearing (ii) Shearing (iii) Sericulture
Which of the two changes frequently, weather or climate?
Sketch the reproductive parts of a flower.
What are decomposers? Name any two of them. What do they do in the forest?
Will the compass needle show deflection when the switch in the circuit shown by Fig.14.24 is closed?