Textbook Solution: The Body and its Movements | Living Science (Ratna Sagar) for Class 6 PDF Download

Oral Questions For Formative Assessment (P-91)

Q1:
Ans: Yes, in unicellular organisms

Q2:
Ans: Different types of cells

Q3:
Ans: Organ system

Q4:
Ans: Nervous system

Q5:
Ans: Reproductive system

Oral Questions For Formative Assessment (P-96)

Q1:
Ans: Protects the organs in the upper part of the body such as heart and lungs. It also gives a skeletal structure for the human physique.

Q2:
Ans: Bone marrow inside the bones

Q3:
Ans: Skull

Q4:
Ans: The backbone has 33 small bones called vertebrae joined together. The joints allow the movement of the backbone.

Q5:
Ans: Ball and socket joint. Hinge joint allows movement in one direction only, while ball and socket joint allows movement in all directions.

Q6:
Ans: No, muscles make the bones move only by pulling.

Oral Questions For Formative Assessment (P-97)

Q1:
Ans: No, examples are earthworm, snail, cockroach

Q2:
Ans: Human, fish: endoskeleton; crab, cockroach, snail: exoskeleton

Q3:
Ans: No. A fish uses its tail fin to push the water and move forward. The side fins are used for balance and for turning.

Q4:
Ans: Snake has a very flexible backbone. It can curve its body into many loops, and each loop pushes against the ground to give the body a forward push. In humans, the backbone is not that flexible.

For Formative and Summative Assessment (P-98)

Q1:
Ans: d

Q2:
Ans: a

Q3:
Ans: b

Q4:
Ans: a

Q5:
Ans: a

Q6:
Ans: a

Q7:
Ans: d

Q8:
Ans: a

Q9:
Ans: a

Q10:
Ans: b

Part - B

Q1:
Ans: False

Q2:
Ans: Circulatory

Q3:
Ans: Digestive

Q4:
Ans: True

Q5:
Ans: Skull

Q6:
Ans: One

Q7:
Ans: Heart, lungs

Q8:
Ans: Femur

Q9:
Ans: True

Q10:
Ans: Triceps

Q11:
Ans: False

Q12:
Ans: True

Q13:
Ans: Exoskeleton

Q14:
Ans: Tail fin

Q15:
Ans: Streamlined shape

Q16:
Ans: Vertebrates

Part - C

Q1:
Ans: A group of cells that performs a special job together is known as a tissue. For example, blood, skin.

Q2:
Ans: The main organs in the digestive system are teeth, food pipe, stomach, small and large intestine. The main function of this system is to digest and absorb nutrients necessary for growth and maintenance of the body.

Q3:
Ans: The soft, inside portion of a bone is known as bone marrow. The main function of bone marrow is to produce blood cells.

Q4:
Ans: The spine allows us to bend or twist our back. It forms the central support for the skeleton and also protects the spinal cord.

Q5:
Ans: The muscles move the bones by their pull. Muscles cannot push. Therefore, to move the bone in one direction, at least two sets of muscles are required.

Q6:
Ans: The three types of skeletons are:

• Exoskeleton: It is a skeleton which is outside the body but is not made up of bones. For example, crabs and snails.
• Endoskeleton: It is a skeleton which is inside the body and made up of bones. For example, humans and fish.
• Liquid skeleton: A liquid skeleton performs the same function as a bony skeleton. For example, earthworms have liquid skeletons. They have liquid trapped in spaces inside the body.

Q7:
Ans: The forelimbs of birds are modified into wings. Their bones are hollow and very light.

Part - D

Q1:
Ans: Group of organs work together to carry out various life activities in our body. Such a group of organs is called an organ system, for example, (i) muscular system: movement of body parts (ii) excretory system: removes waste from the body (iii) reproductive system: produces offspring.

Q2:
Ans:

• a. Earthworms: Muscles squeeze against the liquid trapped in spaces inside the body. The muscles can be squeezed differently to change the body shape. These changes in the shape help the earthworm to move along. To move the earthworm first extends the front part of its body, keeping the rear part fixed to the ground. Next, it fixes the front part and shortens it and pulling rear end forward.
• b. Snake: Snakes have a long and flexible backbone. They can curve their body into many loops. Each loop pushes against the ground to give a forward push to the body.
• c. Fish: Muscles enable the fish to move, contract on one side and expand on the other. The tail fin of the fish moves along with the body in a zig-zag pattern and thus pushes the water. This force moves its body forward. Again, fishes have a streamlined shape which helps in reducing water resistance.

Q3:
Ans: In such joints, the end of one of the bones is round like a ball. It fits into a hollow part (or socket) in the other bone. The bone that ends in a ball can move in any direction. Shoulder joint and hip joint are examples of ball and socket joint. This joint allows movement in all directions.

Q4:
Ans: The main functions of the human skeleton are (i) Support: The skeleton provides the framework which supports the body and maintains its shape. (ii) Protection: The skeleton protects many vital organs like brain, heart, etc. (iii) Movement: The joints between bones permit movements. (iv) Blood cells production: Blood cells are made in the bone marrow inside the larger bones of the body.

Q5:
Ans: The joints in the body are the places where two bones are joined together. The joints are of three types, depending on the types of movement they allow - immovable, slightly movable and freely movable.

Q6:
Ans:

• Endoskeleton: It is the skeletal system which is present inside the body. For example humans, fish, birds and so on.
• Exoskeleton: It is a skeletal system which is present outside the body. It is not made up of bones. For example, crabs, cockroaches, snails and so on.

HOTS Questions

Q1:
Ans: The vertebrae provides flexibility as it allows our back to bend, twist and turn at each joint. Freedom of movement and flexibility of body would have been restricted if the backbone had only one long bone.

Q2:
Ans: No. A fish moves forward by the zig-zag movement of its body and tail fin. The side fins are used for balance, not for moving forward.

Q3:
Ans: Beating of the heart; movement of stomach muscles for churning the food during digestion.