Skeletal & Muscular System Extra Questions And Answers - Class 5 Science | Important Question Answer

Q1: Which of the following statements is true regarding the skeletal system?
(a) Bones are rigid and immovable.
(b) Bones provide a framework for the body and protect internal organs.
(c) The skeletal system is not involved in the production of blood cells.
(d) Bones do not store minerals like calcium and phosphorus.
Ans: (b)
Explanation: Bones form a strong framework that supports the body and shields vital organs such as the heart, lungs and brain. Many bones contain bone marrow, which produces red blood cells, white blood cells and platelets, so the skeletal system is involved in blood cell production. Bones also store minerals like calcium and phosphorus, which the body can use when needed. Options (a), (c) and (d) are incorrect because joints allow movement (so bones are not completely immovable), the skeletal system does help make blood cells, and bones do store minerals.

Q2: During a basketball game, a player jumps to shoot the ball into the hoop. Which type of muscle is primarily responsible for this movement?
(a) Cardiac muscle
(b) Smooth muscle
(c) Skeletal muscle
(d) Involuntary muscle
Ans: (c)
Explanation: Skeletal muscles are attached to bones and are controlled consciously, so they produce voluntary movements such as jumping, running and throwing. Cardiac muscle is found only in the heart and works automatically, while smooth muscle lines internal organs (for example, the stomach) and is also not under conscious control. Option (d) is not a specific muscle type but describes muscles that work without conscious control, so it is not correct here.

Q3: Why do our bones change their shape and size over time?
(a) Due to excessive physical activities
(b) Due to variations in diet
(c) Due to constant wear and tear
(d) Due to seasonal changes
Ans: (c)
Explanation: Bones undergo a continual process of remodelling to repair tiny damage and to adapt to the forces placed on them. This constant wear and tear from everyday activities causes bones to change shape and size so they remain strong and efficient. Physical activity and diet can influence how bones change, but the main reason given here is the ongoing wear and repair process. Seasonal changes do not cause such structural changes.

Q4: Which of the following joints allows rotational movement?
(a) Hinge joint
(b) Ball-and-socket joint
(c) Gliding joint
(d) Pivot joint
Ans: (d)
Explanation: A pivot joint permits rotation around a single axis; a good example is the joint between the first two neck vertebrae that lets the head turn from side to side. A hinge joint (a) allows movement back and forth like a door, a ball-and-socket joint (b) allows movement in many directions including rotation but is not limited to rotation, and a gliding joint (c) allows sliding movements between flat surfaces.

Q5: What happens when the muscular system and skeletal system work together during physical activities?
(a) Muscles relax, and bones become rigid.
(b) Muscles provide support, and bones contract.
(c) Muscles contract, and bones act as levers.
(d) Muscles become rigid, and bones provide flexibility.
Ans: (c)
Explanation: Muscles produce force by contracting. They pull on bones at the joints, and the bones act as levers that change the direction and size of the force to produce movement. This coordinated action allows lifting, running and other movements. The other options are incorrect because bones do not contract (muscles do), and muscles do not simply make bones rigid or provide flexibility by themselves.

Q6: Which of the following is a function of the muscular system beyond locomotion and movement?
(a) Maintaining body temperature
(b) Producing red blood cells
(c) Providing a rigid framework for the body
(d) Producing digestive enzymes
Ans: (a)
Explanation: When muscles contract, they generate heat. This heat helps to maintain a stable body temperature, especially during exercise or in cold conditions. Producing red blood cells is a function of bone marrow (part of the skeletal system), providing a rigid framework is a function of bones, and producing digestive enzymes is a function of certain organs in the digestive system, not muscles.

Q7: In which situation would the skeletal system experience the most stress and adaptation?
(a) Walking on a flat surface
(b) Climbing steep stairs
(c) Sitting at a desk
(d) Swimming in a pool
Ans: (b)
Explanation: Climbing steep stairs requires larger forces from muscles and greater loads on bones compared with gentle walking, sitting or swimming. The increased stress causes bones and muscles to adapt over time, becoming stronger to cope with the extra demand. Swimming places less weight on bones because the water supports the body, and sitting puts little stress on the skeleton.

Q8: How do bones contribute to the immune system?
(a) Producing white blood cells
(b) Acting as a physical barrier against pathogens
(c) Storing antibodies for future use
(d) Facilitating the production of antigens
Ans: (a)
Explanation: Many bones contain bone marrow, which produces white blood cells. White blood cells are crucial for fighting infections, so the skeletal system helps the immune system by making these cells. Bones do not act as a barrier against germs in the same way as skin, they do not store antibodies for later use, and they do not produce antigens (antigens are substances that trigger an immune response).

Q9: Which pair of bones in the human body allow for the movement of the forearm, such as bending and straightening the elbow?
(a) Femur and tibia
(b) Radius and ulna
(c) Scapula and clavicle
(d) Humerus and metacarpals
Ans: (b)
Explanation: The radius and ulna are the two long bones of the forearm. Together with the humerus (upper arm bone) at the elbow joint, they allow bending and straightening of the forearm. The femur and tibia are leg bones, the scapula and clavicle are shoulder bones that help arm movement but do not form the forearm, and metacarpals are bones in the hand.

Q10: Why do athletes engage in regular stretching exercises before and after sports activities?
(a) To increase bone density
(b) To improve muscular strength
(c) To reduce the risk of injuries
(d) To enhance heart rate and circulation
Ans: (c)
Explanation: Stretching before activity helps warm up muscles and increase their flexibility, which reduces the chance of strains and tears during exercise. Stretching after exercise helps muscles relax and recover, reducing stiffness. While stretching can contribute indirectly to performance, increasing bone density and improving muscular strength require weight-bearing exercise and strength training rather than stretching alone; stretching also has only a limited direct effect on heart rate and circulation.