Short Answer TypeExplain the term Regeneration as used in relation to reproduction of organisms. Describe briefly how regeneration is carried out in multicellular organisms like Hydra.
A student adds a spoon full of powdered sodium hydrogen carbonate to a flask containing ethanoic acid. List two main observations, he must note in his note book, about the reaction that takes place.Also, write the chemical equation for the reaction.
List two reasons for the appearance of variations among the progeny formed by sexual reproduction.
(i) Name the part marked 'A' in the diagram.
(ii) How does 'A' reaches part 'B'?
(iii) State the importance of the part 'C'.
(iv) What happens to the part marked 'D' after fertilisation is over?
Name the type of mirrors used in the design of solar furnaces. Explain how high temperature is achieved by this device.
Concave mirrors are used for the design of solar furnaces because they are converging mirrors. When a solar furnace is placed at the focus of a large concave mirror, it focuses a parallel beam of light on the furnace. Thus, a high temperature is achieved after a few minutes.
Two areas of study namely evolution' and classification' are interlinked. Justify the statement.
The activities of man had adverse effects on all forms of living organisms in the biosphere. Unlimited exploitation of nature by man disturbed the delicate ecological balance between the living and non-living components of the biosphere. The unfavourable conditions created by man himself threatened the survival not only of himself but also of the entire living organisms on the mother earth. One of your classmates is and active member of 'Eco club' of your school which is creating environmental awareness amongst the school students, spreading the same in the society and also working hard for preventing environment degradation of the surroundings.
(a) Why is it necessary to conserve our enviroment?
(b) State the importance of green and blue dust-bins in the safe disposal of the household waste.
(c) List two values exhibited by your classmates who is an active member of Eco-club of your school.
Describe an activity to show that the colours of white light split by a glass prism can be recombined to get white light by another identical glass prism. Also, draw a ray diagram to show the recombination of the spectrum of white light.
A student is observing a permanent slide showing sequentially the different stages of asexual reproduction taking place in yeast. Name this process and draw diagrams of what he observes, in a proper sequence.
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