Tick the correct answer:
(a) Yeast is used in the production of
(i) sugar (ii) alcohol (iii) hydrochloric acid (iv) oxygen
(b) The following is an antibiotic
(i) Sodium bicarbonate (ii) Streptomycin (iii) Alcohol (iv) Yeast
(c) Carrier of malaria-causing protozoan is
(i) female Anopheles mosquito (ii) cockroach (iii) housefly (iv) butterfly
(d) The most common carrier of communicable diseases is
(i) ant (ii) housefly (iii) dragonfly (iv) spider
(e) The bread or idli dough rises because of
(i) heat (ii) grinding (iii) growth of yeast cells (iv) kneading
(f) The process of conversion of sugar into alcohol is called
(i) nitrogen fixation (ii) moulding (iii) fermentation (iv) infection
(a) (ii) Alcohol
Yeast is used in the production of alcohol. This process is known as fermentation.
(b) (ii) Streptomycin
Streptomycin is an antibiotic, it is used to relieve the pain and kills other disease causing microorganisms.
(c) (i) Female Anopheles mosquito
Malaria is caused by a mosquito. The carrier of Malaria causing protozoan is Female Anopheles mosquito.
(d) (ii) Housefly
The most common carrier of communicable disease is housefly. It spreads the disease causing microorganisms.
(e) (iii) Growth of yeast cells
This process is called as fermentation. The dough rises due to the increased growth of yeast cells.
(f) (iii) Fermentation
The conversion of sugar into alcohol with the help of yeast cells is called as fermentation.
Describe with the help of a diagram an instrument which can be used to detect a charged body.
Sketch larynx and explain its function in your own words.
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
Make a labelled diagram of a candle flame.
What is metamorphosis? Give examples.
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.
Make sketches of animal and plant cells. State three differences between them.
What is a constellation? Name any two constellations.
Describe the construction of a kaleidoscope.
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.
Make a sketch of the human nerve cell. What function do nerve cells perform?
Explain why objects moving in fluids must have special shapes.
Sketch larynx and explain its function in your own words.
What is a constellation? Name any two constellations.
Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?
What is menstruation? Explain.
Make a labelled diagram of a candle flame.
Write notes on—
(a) Adam’s apple.
(b) Secondary sexual characters.
(c) Sex determination in the unborn baby.
It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain.
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.