Fill in the blanks:
(a) Microorganisms can be seen with the help of a ____________.
(b) Blue green algae fix __________ directly from air to enhance fertility of soil.
(c) Alcohol is produced with the help of __________.
(d) Cholera is caused by __________.
(a) Microscope
Microorganisms can be seen with the help of microscope because they are very small in size. We cannot see the microorganisms with the naked eyes.
(b) Nitrogen
To increase in the fertility of the soil, the composition of nitrogen should be rich in soil. Blue green algae fix the nitrogen from environment and increases the fertility of the soil.
(c) Yeast
The process of fermentation of alcohol with the help of yeast which is known as fermentation process. With the help of yeast, the carbon dioxide gas production occurs.
(d) Bacteria
Cholera is a water- born bacterial disease. It spreads by impure water.
Popular Questions of Class 8 Science
- Q:-
Describe with the help of a diagram an instrument which can be used to detect a charged body.
- Q:-
Sketch larynx and explain its function in your own words.
- Q:-
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
- Q:-
Make a labelled diagram of a candle flame.
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What is metamorphosis? Give examples.
- Q:-
The following Table shows the total power shortage in India from 1991– 1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.
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Make sketches of animal and plant cells. State three differences between them.
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What is a constellation? Name any two constellations.
- Q:-
Describe the construction of a kaleidoscope.
- Q:-
Complete the crossword with the help of clues given below:
Across
1. This is necessary for photosynthesis.
3. Term for component present in the cytoplasm.
6. The living substance in the cell.
8. Units of inheritance present on the chromosomes.Down
1. Green plastids.
2. Formed by collection of tissues.
4. It separates the contents of the cell from the surrounding medium.
5. Empty structure in the cytoplasm.
7. A group of cells.
Recently Viewed Questions of Class 8 Science
- Q:-
In the following statements, tick T against those which are true, and F against those which are false:
(a) Sound cannot travel in vacuum. (T/F)
(b) The number of oscillations per second of a vibrating object is called its time period. (T/F)
(c) If the amplitude of vibration is large, sound is feeble. (T/F)
(d) For human ears, the audible range is 20 Hz to 20,000 Hz. (T/F)
(e) The lower the frequency of vibration, the higher is the pitch. (T/F)
(f) Unwanted or unpleasant sound is termed as music. (T/F)
(g) Noise pollution may cause partial hearing impairment. (T/F) - Q:-
Make a sketch of the human nerve cell. What function do nerve cells perform?
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Find out the information about the national parks in your state. Identify and show their location on the outline map of India.
- Q:-
Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?
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The table below shows the data on likely heights of boys and girls as they grow in age. Draw graphs showing height and age for both boys and girls on the same graph paper. What conclusions can be drawn from these graphs?
- Q:-
Complete the cross-word puzzle using the hints given below
Across
1. The process of the fusion of the gametes.
6. The type of fertilization in hen.
7. The term used for bulges observed on the sides of the body of Hydra.
8. Eggs are produced here.Down
2. Sperms are produced in these male reproductive organs.
3. Another term for the fertilized egg.
4. These animals lay eggs.
5. A type of fission in amoeba. - Q:-
How is an embryo developed?
- Q:-
One day Reeta went to a jeweller’s shop with her mother. Her mother gave old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?
- Q:-
Write short notes on the following:
(a) Cytoplasm
(b) Nucleus of a cell - Q:-
Which of the following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.
- NCERT Chapter