Class 7 Science Skeleton Joints and Muscles Textbook Question Answers , Fill in the blanks as well as additional QA.
[1] Choose the correct answers.
Ball and Socket joint is found in
- a) Shoulder and arm bone
- b) Elbow
- c) Upper jaw
- d) Wrist
Vertebrae are found in
- a) Skull
- b) Hands
- c) Backbone
- d) Fingers
Cartilage is found in
- a) Hands
- b) Ear
- c) Foot
- d) Skull
Hinge joint is found in
- a) Upper jaw
- b) Elbow
- c) Lower jaw
- d) Shoulder
[2] Correct and rewrite the following sentences
- a) Cartilage protects soft organs like brain and lungs from injury.
- b) Bones of the hand are connected to the Pelvic girdle. [pectoral girdle]
- c) The brain is protected by the rib cage. [skull]
- d) Bones and muscles together form the muscular system. [correct]
[3] Answer the following questions.
a) In which part of the body is the longest bone located in your body found?
a) The longest bone in the body, the femur, is located in the thigh.
b) What is the use of the backbone in the body ?
b) The backbone (vertebral column) provides structural support, enables flexibility, and protects the spinal cord.
c) Explain the joints found in the fingers and knee.
c) In the fingers, there are hinge joints that allow movement in one direction. The knee, on the other hand, has a hinge joint as well as a sliding joint, enabling both flexion and extension as well as some rotation.
d) Why can’t earthworms stand up straight like human beings?
d) Earthworms lack a rigid internal skeleton like humans, so they rely on the hydrostatic pressure of their fluid-filled body to support their shape. This fluid-based structure prevents them from standing up straight.
f) What would happen if there were no joints in our fingers ?
f) If there were no joints in our fingers, we would not be able to bend them. Our fingers would be rigid, limiting our ability to perform various tasks that require dexterity and fine motor skills.
g) What is the difference between bone and Cartilage ?
g) The difference between bone and cartilage:
- Bone is hard and rigid, providing structural support and protection.
- Cartilage is softer and more flexible, providing support in areas that need flexibility, like the ears and nose.
Additional Question and Answers
Which bones form the cage protecting the lungs and heart in the chest?
The sternum (central bone in the front of the chest) and ribs (connecting the sternum to the vertebrae) form the cage protecting the lungs and heart in the chest.
How many bones are there in the pelvic girdle, and where is it attached?
The pelvic girdle consists of two bones, one on each side. It is attached to the backbone and the thigh bone.
What is the longest and strongest bone in the human body?
The thigh bone (femur) is the longest and strongest bone in the human body.
What are joints, and why are they important?
Joints are the places where bones are joined together. They are important because they enable movement in different parts of the body.
What is the role of cartilage in the body?
Cartilage is soft and flexible. It provides support and is found in the ears, nose, between vertebrae, in the backbone, and between ribs and the chest bone.
