Heredity and Evolution — Science STD 10 — Question

The non - metal A is an important constituent of our food and most of the fuels around us. A forms two oxides B and C. The oxide B is poisonous whereas oxide C causes global warming.

1. Identify A, B and C.
2. To which group of periodic table does A belong?
3. Name another element which is placed in the same group as A.

How are the properties of an alloy different from those of the constitutent elements?

Determine how far an object must be placed in front of a converging lens of focal length 10cm in order to produce an erect (upright) image of linear magnification 4.

When zinc metal is treated with a dilute solution of a strong acid, a gas is evolved, which is utilised in the hydrogenation of oil. Name the gas evolved. Write the chemical equation of the reaction involved and also write a test to detect the gas formed.

Explain with the help of labelled ray diagram, the defect of vision called myopia and how it is corrected by a lens.

Comment on the following statements:
(i) Bee sting is treated with baking soda paste whereas wasp sting is treated with dilute vinegar.
(ii) Farmers treat soil with quicklime when tilling.
(iii) Ancient sculptures and marble structures are conserved by treating them with certain chemicals."

Explain Mendel's observation when he crossed a homozygous tall (TT) plant with homozygous dwarf (tt) plant followed by self-cross.

Is it true that evolutionary relationship is linked to classification? Explain with an example.