Crocodile has very strong jaws, very hard back cover and can live on land also. It can live hungry for quite a long time. It is a social animal and does sharing with group.

Plants obtain their food by the process of photosynthesis. In this process, green plants trap sunlight with the help of chlorophyll and prepare glucose from carbon dioxide and water. Oxygen is given out from plants as a by-product.

Water cycle is the continuous journey of water from the surface of earth to atmosphere and back.

Wood and plastic are the materials which are float on water.

From the given characteristics, it can be concluded that the given plant is a tree.

Following steps are used to prepare a magnetic compass by using an iron needle and a bar magnet:
(i) Take a small piece of cork, and the magnetised needle (which can be magnetised by using a bar magnet).
(ii) Take a cup filled with water and let the cork float on it; the needle should not touch the water.
(iii) Now, compass is ready to work. Note the direction in which the needle points when the cork is floating.
(iv) Rotate the cork in different directions. Note the direction in which the needle points when the cork begins to float again without rotating. We see that the needle always points in the same direction, when the cork floats without rotation

Activity showing magnetic compass by using iron needle and a bar magnet

Wrong statements :
(a) Anther is a part of the pistil.
Correct statement: Anther is a part of the stamen.
(b) The visibleparts of a bud are the petals.
Correct statement: The visible parts of a bud are the sepals.
(d) Leaves perform the function of transpiration only.
Correct statement: Leaves perform the functions of both photosynthesis and transpiration.

(a) Air is dissolved in water in the form of oxygen. Tiny bubbles are formed, when air present in the water escape on boiling it. So, tiny bubbles appeared due to the evolution of air dissolved in water.
(b) No, tiny bubbles will not appear as there is no dissolved air in this water.

The shadow of the object cannot be caught if the screen and the object are very far from each other. This is the same case, the shadow of the football cannot be seen on the ground when it is kicked high in the air. This happens because if we take the object away and away from the screen, the image becomes smaller and smaller and a time comes when it disappears from the screen.

(a) No, the anklets were made of pure silver.
(b) Silver anklets lost their lustre and appear dull, because of the action of air and moisture on them.
(c) Kavita's mother is knowledgeable and intelligent.

(1) It helps in gaining systematic knowledge of things.
(2) It gives a general idea about all the members of a group and the differences between the members of different groups.
(3) It is convenient to work with all members of a group after knowing their properties

Roots perform following functions in the plant:
(a) Roots absorb water and minerals from the soil.
(b) Roots hold the plant to the soil.
(c) Roots store food.

(a) Non-biodegradable wastes such as broken glass, aluminium wrappers, plastic, polythene bags, etc cannot be converted into compost by the redworms.
(b) Yes, saprophytic organisms such as moulds and bacteria, are also helpful in the decomposition of biodegradable substances. Saprophytic organisms feed on dead and decaying matter.

Among copper, silver and aluminium, we use copper and aluminium not silver for household wires because copper and aluminium are much cheaper than silver and silver is used as an ornaments and is also heavier than copper and aluminium.

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