Write one similarity and one difference between the nutrition in amoeba and human beings.
Similarity: Amoeba and humans are heterotrophs. This means we need to derive energy from other organic sources of carbon.
Difference: Amoeba captures the food with the help of pseudopodia and engulf it. In human beings food is taken by the mouth.
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
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
Which of the following are not correct?
(i) The basic unit of time is second.
(ii) Every object moves with a constant speed.
(iii) Distances between two cities are measured in kilometres.
(iv) The time period of a given pendulum is not constant.
(v) The speed of a train is expressed in m/h.
In the circuit shown in Fig. 14.25
(i) Would any of the bulb glow when the switch is in the ‘OFF’ position?
(ii) What will be the order in which the bulbs A, B and C will glow when the switch is moved to the ‘ON’ position?
What is sludge? Explain how it is treated.
Explain why there is no waste in a forest.
Distinguish between a parasite and a saprotroph.
State the characteristics of the image formed by a plane mirror.
Explain how soil is formed.
Choose the correct option from the following:
Plants take carbon dioxide from the atmosphere mainly through their:
(i) roots (ii) stem (iii) flowers (iv) leaves
Explain how groundwater is recharged?
Match the words of Column I with those given in Column II:
Column I Column II
1. Scouring (a) Yields silk fibres
2. Mulberry leaves (b) Wool yielding animal
3. Yak (c) Food of silk worm
4. Cocoon (d) Reeling
(e) Cleaning sheared skin