HOTS Questions: Body Movements | Class 6: Additional Practice PDF Download

Q1: What makes snakes move fast on the ground?
Ans: Snakes move quickly on the ground because of their special belly scales. These scales have tiny, rough parts that help them grip the ground. Snakes push their bodies forward using muscles and their scutes, which act like tiny hooks gripping the ground. By moving their muscles in a special way, snakes can move forward in a straight line.

Q2: Give adaptations of birds to flight.
Ans: Birds have special features for flying:

• Hollow Bones: Their bones are light but strong.
• Strong Muscles: Their chest muscles are powerful for flapping wings.
• Good Breathing: They have air sacs that keep them breathing well during flight.
• Feathers: Feathers help them fly and keep warm.
• Keel (Sternum): This part gives space for strong flight muscles.
• Lightweight Body: They have no teeth and less heavy bones.
• Strong Heart: A strong heart pumps blood for flight.

Q3: What is a joint? Name the kinds of joints present in our body.
Ans: A joint is where two or more bones meet. There are three types of joints:

• Fixed Joints: These don't move, like the joints in our skull.
• Slightly Movable Joints: These move a little, like the joints in our spine.
• Freely Movable Joints: These move a lot and include:
• Hinge Joints: They move like a door hinge, found in our elbows and knees.
• Ball and Socket Joints: These let us move our arms and legs in many directions.
• Pivot Joints: These help us turn our head left and right.
• Gliding Joints: These let our wrists and ankles move.
• Condyloid Joints: These allow us to move our fingers in different ways.

Q4: Cockroaches can fly as well as walk, how?
Ans: Cockroaches have two pairs of wings. When they want to fly, they lift the outer wings and unfold their inner wings, which are used for flying. These wings help them move through the air. But when they are not flying, they fold their wings back and use their six legs to walk.

Q5: Why is the upper part of our ear not as soft as the earlobe?
Ans: The upper part of the ear, called the "pinna," is not soft because it has cartilage, which is tough and firm. The earlobe is soft because it has more fat. Cartilage makes the upper ear strong, while fat makes the earlobe soft.

Q6: What are voluntary and involuntary movements? Give examples of each.
Ans: Voluntary movements are actions that we consciously control, such as walking, running, and jumping. Involuntary movements, on the other hand, are actions that occur without our conscious control, like heartbeat, digestion, and blinking.

Q7: Describe the importance of skeleton in the human body.
Ans: The skeleton provides shape, support, and protection to the body organs. It helps in movement by providing attachment points for muscles. Additionally, the bone marrow within the bones produces blood cells, contributing to the body's immunity and oxygen transportation.

Q8: How do muscles work in pairs during body movements? Provide an example.
Ans: Muscles work in pairs - one contracts while the other relaxes. For instance, when you bend your arm, the biceps muscle contracts (shortens) while the triceps muscle relaxes (lengthens). When you straighten your arm, the triceps muscle contracts, and the biceps muscle relaxes.

Q9: Explain the importance of a pivot joint in our body. Provide an example.
Ans: A pivot joint allows rotational movement in one plane. An example is the joint between the first and second vertebrae of the neck. This joint enables us to turn our head from side to side, allowing us to look around without moving our entire body.

Q10: Explain the difference between ball and socket joint and hinge joint with suitable examples.
Ans: Ball and socket joint allows movement in various directions, like the hip joint. Hinge joint permits movement in one direction only, like the elbow joint.