Life Processes — Science STD 10 — Question

What does CNS stand for? Which part of CNS:

1. Consists of two cerebral hemispheres, and
2. Has spinal nerves attached to it?

Giving an example list two information which make a chemical equation more useful. (informative).

Define : Calcination

If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.

Some insects are very useful for us. We get many products from them. e.g. Honey bee, Lac insect, Silk worm, are the insects that provide us with honey and wax, lac and silk respectively. The culture experiments are done on these insects for large scale production of these substances. Butterflies help in the pollination of crops and are thus helpful for the farmers and gardeners. Lady bug beetle is an insect which acts as a natural pest control as it attacks the other harmful insect pests.

In biological pest control methods it is widely used. Some insects, on the contrary are very harmful. Mosquito, bed bugs, lice are blood sucking parasites which can spread the diseases. Mosquito is a vector for dengue, filariasis and malaria. Some are biting insects that can cause wounds, some cause allergies of various kinds. The grains and crops are destroyed to great extent by the insects. In this way the insects belonging to the phylum Arthropods are harmful to health, wealth and peace of mind too.

(ii) Which are the animals from phylum Arthropoda those have shortest and longest life span?

What is the difference between the cuttings method and grafting method for the artificial propagation of plants?

Explain why, diamond has a high melting point.

Friedrich Wohler converted an inorganic compound into an organic compound in the laboratory.

1. Give the name and formula of inorganic compound.
2. Write the name and formula of organic compound formed.

Arrange the above elements vertically downwards in an increasing order of atomic radii.