One of the following is not a biodegradable material. This one is:
(a) cotton
(b) animal bones
(c) aluminium foil
(d) wood
(c) aluminium foil Aluminium foil cannot be degraded by the action of micro-organisms and hence is non-biodegradable.
(a) What is meant by non-biodegradable waste materials? Give two examples of non-biodegradable wastes.
(b) Which of the following materials are biodegradable? Animal bones, Iron nails, Plastic mugs, Leather belts, Silver foil.
One of the following animals does not use tracheae as the respiratory organs. This animal is : (a) grasshopper (b) prawn (c) mosquito (d) cockroach