List five products we get from forests? | Class 7 Science Chapter Forests: Our Lifeline, Forests: Our Lifeline NCERT Solutions

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

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

Sketch the cross section of soil and label the various layers.

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?

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.

Sketch the reproductive parts of a flower.

Describe how crystals of copper sulphate are prepared.

Why does an athlete breathe faster and deeper than usual after finishing the race?

Write one similarity and one difference between the nutrition in amoeba and human beings.

Match the items in Column I with those in Column II:
Column I                             Column II
(a) Yeast                             (i) Earthworm
(b) Diaphragm                    (ii) Gills
(c) Skin                               (iii) Alcohol
(d) Leaves                          (iv) Chest cavity
(e) Fish                               (v) Stomata
(f) Frog                               (vi) Lungs and skin
                                           (vii) Tracheae

A carnivore with stripes on its body moves very fast while catching its prey. It is likely to be found in

(i) polar regions          (ii) deserts
(iii) oceans                 (iv) tropical rainforests

State differences between acids and bases.

Why is blood needed by all the parts of a body?

Describe the steps involved in getting clarified water from wastewater.

Explain the relationship between sanitation and disease.

Why should oils and fats be not released in the drain? Explain.

Explain the factors responsible for the depletion of water table.

Give one use each of a concave and a convex mirror.

Match items in Column I with those in Column II:

Column I                             Column II
(a) Bud                                  (i) Maple
(b) Eyes                                (ii) Spirogyra
(c) Fragmentation                 (iii) Yeast
(d) Wings                              (iv) Bread mould
(e) Spores                             (v) Potato
                                              (vi) Rose