Snakes in the desert burrow deep into the sand during the day time because the deeper layers of sand are cooler which allow them to stay away from heat of the desert that persists through the day time.

In grasslands, there are limited number of trees and places for animals to hide. When the enemy attacks an animal, it has to run fast, so as to reach a safe place. if it fails, it has to loose its life. So, speed in such places as grasslands is very important for the survival of animals.

Following are the non-living things from the list which were once part of living things:
Butter - Obtained from milk from dairy animals
Leather - From animal skin
Wool - From hair of sheep or goat
Cooking oil - Seeds of plants
Apple - Fruit from apple tree
Rubber - Latex of rubber tree

Cloud is an example of non-living thing which shows following two characteristics of living things:
(i) It increases or decreases in size
(ii) It shows movements.
(Another example can be a car move from one place to another and also requires energy, i.e. petrol).

The surroundings where organisms live is called habitat. The organisms depend on their habitat for food, water, air, shelter and other needs. e.g. Habitat of a camel is a desert.

(a) Plants growing in different places appear different due to the presence of unique adaptive features which can be morphological or functional
(b) It is called a habitat. It provides food, water and shelter, etc., to all living organisms
(c) Two types of habitats have been observed
(i) terrestrial (ii) aquatic
(d) Leaves of cactus present in desert are thorn like (spines) on reduced to green fleshy stem, to reduce rate of transpiration while leaves of trees like deodars have cone or pine-shaped leaves to let show falling on them slide off easily.
(e) Ravi and Ritu both are adventurous, curious and observant. They are learners and have scientific temperament.

(a) The plant responded to the stimuli of light. Since, light was coming through window so, plant grew towards that direction.
(b) (i) Yes, all living things responds to changes around them. These changes are called stimulus and our reaction towards them is response.
(ii) Folding/Closing of 'touch-me-not' plant leaves when someone touches its leaves closing of eyes due to sudden bright light
(c) She is careful, responsible and observant. She is also curious about unique behaviours and has an inquistive/enquiring nature.

Reproduction is important for organism as it leads to the production of more individuals of an organism of its own kind. This helps in continuity of life on the earth.

Rose and jasmine can be produced by stem cuttings.

Carbon dioxide is given off and oxygen is taken in our lungs.

Habitat is a place where animal lives and gets its food.

Seeds respire so, it can be identified as living beings.