Class 6 Science Chapter 5 Practice Question Answers - Body Movement

Q1: What is a skeleton? State its functions.
Ans: The skeleton is the framework of bones and cartilage that supports and protects the body’s soft tissues and internal organs.
Functions of the skeleton:

• The skeletal system provides shape to the body.
• It works as a support structure for your body.
• It facilitates movement.
• It produces blood cells.
• It protects organs.
• It stores minerals and fats.

Q2: List the names of three animals that have streamlined bodies.
Ans:

• Birds
• Fishes
• Snakes

Q3: What is a muscle? Explain how it helps in movement.
Ans: Muscles are soft tissues. Many stretchy fibres make up your muscles. Different types of muscles have different functions. . Muscles are attached to the bones through a long fibre called a tendon. There are more than 600 muscles in our body.
Muscles always function in pairs. In a pair of muscles, when one contracts, the other muscle relaxes. A muscle can only return to its initial position after the other muscle in the pair contracts.

Q4: What is cartilage?
Ans: Cartilage is a soft, elastic, and flexible connective tissue. It prevents the bones from rubbing against one another.

Q5: Snail moves with the help of its
(a) shell
(b) bone
(c) muscular foot
(d) whole body
Ans: (c)
The snail’s strong muscular foot extends outside during locomotion and is attached to the ground. It creates a sequence of waves that the snail can use to propel itself forward. A unique gland in a snail’s foot produces a slimy mucus that creates a slick surface that helps the snail walk more easily.

Q6: Name the longest bone in our body.
Ans: The femur is the longest bone in our body.

Q7: Provide one-word answers to the following statements given below.

• Joint, which allows movement in all directions.
• The rigid structure forms the skeleton.
• Part of the body with a fixed joint.
• Help in the movement of the body by contraction and relaxation.
• Bones that join with the chest bone at one end and to the backbone at the other end.
• The framework of bones gives shape to our body.
• Bones that enclose the organs of our body that lie below the abdomen.
• Joint where our neck joins the head.
• Part of the skeleton forms the earlobe.

Ans:

• Ball and socket joint
• Bone
• Upper jaw with the skull
• Muscles
• Ribs
• Skeleton
• Pelvic bones
• Pivotal joint
• Cartilage

Q8: Bones are hard structures and cannot be bent. However, we can still bend our elbows, knees, etc. How is this possible?
Ans: The existence of several types of joints between the bones allows us to bend various bodily parts, including the elbow, knee, back, etc. The hinge joint connects two or more bones, which make up the elbow and knee, rather than just one bone. We can bend our elbows and knees with the help of these muscles and this joint.

Q9: What is the name of the small bone which makes up the backbone?
Ans: Vertebrae is the name of a small bone which makes up the backbone.

Q10: Name various parts of the skeletal system.
Ans: The skeletal system can be divided into the following main parts:

• Skull
• Limb bones
• Backbone
• Shoulder bones
• Chest bones
• Hip bones.

Q11: Underwater divers wear fin-like flippers on their feet to
(a) swim easily in the water
(b) walk over the bottom of the sea(sea bed)
(c) look like a fish
(d) walk on water’s surface
Ans: (a)
When swimming, the muscles in the front section contract, creating a wave-like curve on one side, and the fin-like flippers move on the opposite direction, pushing the underwater divers forward by putting force on the water around them.

Q12: Name the type of joint of your hand that helps you grasp a badminton racquet.
Ans: Hinge joints in our fingers help us grasp a badminton racquet.

Q13: Name the three components of the skeleton.
Ans: Skeleton is made up of three different components. They are bones, joints and cartilage.

Q14: List the organs that are protected by the rib cage.
Ans: The organs that are protected by the rib cage are

• Heart and
• Lungs

Q15: Why do animals move from one position to another?
Ans: Animals move from one place to another for various reasons:

• To obtain their food and shelter.
• Most animals that migrate do so to find food or more livable conditions.
• To protect themselves from enemies and unfavourable climates.
• Some animals migrate to breed.

Q16: What would have happened if our backbone had been made of one single bone?
Ans: If our backbone had only one bone, we would not be able to bend and twist our backbone.

Q17: How many types of joints are there? Explain each of them.
Ans: The main types of joints in the human are:

• Hinge joint: Hinge joints allow bones to move in only one direction, i.e. back and forth.
• Ball and socket joint: A “ball”-shaped bone end that fits into a “socket” (hollow space) in another bone makes up the ball and socket joint. Such joints, like the hip and shoulder joints, permit movement in all directions.
• Pivot joint: A cylindrical bone rotates within a ring-shaped bone in a pivot joint. The pivot joint permits movement in both directions, including right and left, for example, at the neck joint.
• Fixed joint: In certain joints, the bones are held together so firmly that they are completely immobile.

Q18: Boojho hurt his ankle after falling off a tree. The doctor found that the ankle was fractured after the examination. How was it detected?
Ans: A doctor must have examined the affected area for oedema and obtained an ankle X-ray. The forms of the bones in our body are visible in X-ray scans. The doctor may have confirmed a fracture in the ankle by glancing at the x-ray.

Q19: Do all animals have bones?
Ans: No, not all creatures have bones. The only creatures with bones are those with backbones. Sharks’ skeletons are the only ones fully formed of cartilage among animals with backbones. The bodies of leeches, worms, and jellyfish are not supported by solid structures.

Q20: What is bone marrow? Give its main function.
Ans: Bone marrow is a spongy substance found in the centre of the bones. Its main function is to produce new blood cells to replace damaged and worn-out ones.