1. In class questions and answers:

  1. What is your skeleton made up of?

Ans: Skeleton is made up of bones and cartilages.

  1. Where do we find immovable joints in the human body?

Ans: The immovable joints are found in the skull.

  1. You are able to move your wrist back and forth and sideways. What kind of joint does it have?

Ans: The wrist has gliding joints which allows the sideways movement as well as back and forth movements.

  1. Name the joint that helps in the movement of the neck?

Ans: The joint that helps in the movement of the neck is pivotal joint.


Exercise

  1. Tick (✓) the correct option to complete each sentence.

  1. Muscles are attached to the bones by…

Joints        Tendons       Hair       Fins

Ans: tendons

  1. Two bones are held together by tissues called…

Cartilage        tendons         ligaments         blood

Ans: ligaments

  1. The hinge joint is found in the…

Elbow       neck       shoulder         wrist

Ans: elbow

  1. The bones of a movable joint are lubricated by…

Muscles     tendons     synovial fluid      ligaments

Ans: synovial fluid

  1. The ball and the socket joint….

allows the movement of body parts in one direction          allows the movement of body parts in several directions       does not allow the movement of body parts in any direction       allows the movement of body part in two directions

Ans: allows the movement of body parts in several directions

  1. A butterfly has…

an internal skeleton        an exoskeleton       a bony skeleton         a skeleton of only cartilage

Ans: an exoskeleton

    II.     Where do you find the following joints in the human body?

  1. Ball and socket joint………..

Ans: shoulder

  1. Hinge joint………..

Ans: elbows

  1. Pivotal joint……….

Ans: neck

  1. Gliding joint………..

Ans: wrist

  1. Immovable joint………..

Ans: skull

   III.     Answer the following questions in one sentence.

  1. Which tissues join a muscle to a bone?

Ans: The tissues called  tendons join a muscle to a bone.

  1. What are the wings of insects made of?

Ans: The wings of insects are made up of cuticle

  1. What has a rich supply of blood - bones or cartilages?

Ans: Bones have a rich supply of blood.

  1. What protects the bones at the joints?

Ans: The cartilage protects the bones at the joints.

  1. Name the fluid that lubricates the joints?

Ans: The fluid that lubricates the joints is synovial fluid.

  1. Which body part helps ducks swim?

Ans: The webbed feet of duck helps ducks swim.

    IV.    Answer the following questions in two sentences.

  1. Differentiate between tendons and ligaments.

Ans: Tendons: Tendons are the tissues that keep the muscles attached to the bones.

        Ligaments: The ligaments are the tissues that hold the bones together at the joints.

  1. Differentiate between ball and socket, and hinge joints.

Ans: Ball and socket joints: This type of joints allows the movements of body parts in several directions. The joints of legs at the hip and arms at the shoulder are of this type.

        Hinge joints: This type of joints allows only one directional movement. The joints of knees and elbows are of this type.

  1. Why are you able to bend your back?

Ans: We are able to bend our back because our back is supported by the flexible column of bones called the vertebral column.

  1. How do earthworms move?

Ans: An earthworm has hair-like projection on its body called bristles. The earthworm holds grip on the soil by sticking its bristles and then pushes itself forward or backward by stretching and contracting its muscles.

  1. What enables a snail to move on very sharp edges?

Ans: A snail has a gland that produces slimy mucus, it hardens in the contact of air. This protect the snail from sharp objects. That is the hardened mucus enables the snail to move on very sharp edges.

     V.    Answer in about four to five sentences.

  1. Which body features help the bird fly?

Ans: The skeleton of birds is made up of porous and hollow bones. It reduces the body weight. The streamlined shape of the body of a bird help in flying.

  1. Explain with diagrams how snakes move.

Ans: The snakes move by sliding their bodies. The body of a snake is covered with scales (special structure of its skin), it helps a snake to hold grip and move forward.

        The movement of a snake is explained in the following figure.

  1. Write a short note on the human skeleton.

Ans: Human skeleton is made up of 206 bones (in adult) and several cartilages. The bones are hard and rigid.The bones are richly supplied by blood vessels. Two bones meet at the joints with different special joints. Ligament are the tissues that hold the bones together at the joints. The tissue called cartilage gives protection to the bones at the joints. The skeleton is made up of different parts like skull, vertebral column, rib cage, arms and legs, movable and immovable joints etc.

         The skeleton has three main functions:

  • It supports the body and helps it to maintain its shape.

  • It protects the internal organs of the body.

  • It helps the body to move.

  1. Explain the body features of a cockroach which enable it to move and fly.

Ans: A cockroach moves with its legs, the spines on its legs enable it to move on sand and tiled surfaces. The breast muscles move the wings and help the cockroach to fly.