NCERT Science Chapter 8 Body Movements Activity Answers

How do animals move from place to place?

Answer:

Animal Body        Body art used       How it moves

Cow: Legs: Walk

Humans: Legs: Walk

Snake: Whole Body: Slither

Bird: Wings: Fly

Insect: Wings: Fly

Fish: Fins: Swim

Activity 1

Activity 1 asks us to apply a stick to arm and see if we can move our arms or not.

Answer: Stick restrict the movement of the arm, so we can not move it.

 

 

Movents in our body

Activity 2

Activity 2 asks us to make a ball and socket joint using a bowl, a rubber ball and a stick and see if it can move.

Answer: The ball and socket joint moves freely in the bowl.

Explanation: This activity tells us how some of our joints, like shoulder and hip joint work.

 

Activity 3

Activity 3 asks us to make a hinge joint using a cylinder made of cardboard and a pencil.

Answer: Hinge joints allow movement only in one direction. This activity tells us how are hinge joints present in arm and knee works.

Activity 4

Activity 4 asks us to breathe deep and check our chest bones.

Answer: We have twelve chest bones we call them ribs. Ribs are attached to chest bone in the front and with backbone in back. Together they form a box type structure. We call it rib cage. Rib cage helps us in breathing and also protect some of our organs which lie inside them.

Activity 5

This activity asks us to observe the movement of an earthworm.

Answer: Earthworm does not have bones. It has circular rings of muscles. Muscle in the front expands while the muscles in the back contracts. By this way, an earthworm moves.

Earthworm contains thin hair-like structures. At the time of expanding in front, these hairs provide the grip to muscles in the back.

Activity 6

This activity asks us to observe the movement of a snail.

Answer: Snail has finger-like muscle at the bottom. We call them snail foot. Snail uses these muscles to move from one place to another.

Activity 7

The activity asks us to push a paper boat from back and side and compare the force needed to push the boat.

Answer: We need more force to push sideways.

Pushing through boat from back require lesser force as the boat is in a streamlined position.

Application: Fish moves in streamline way to counter lesser resistance from the water.

See also:

• 7. Getting to Know Plants.
• 8. Body Movements.
• 9. The Living Organisms – Characteristics and Habitats.