Q1.Choose the correct option.   

a.Animal X is a vertebrate It  has muscles and bones but it moves by contraction and expansion of the body. Animal X is  a /an_______

i. snail ii. snake iii. earthworm iv cockroach

Answer: ii. snake

b. Select the option to match the pairs.

Types of Joints	Extent of movement
Ball and socket joint	I. Allows movement only in one direction
(b)Hinge joint	II Allows rotatory movement around a single axis
(C) Gliding joint	III Allows maximum movement in all directions
(d) Pivot joint	IV. Allows little movement in all directions

i.(a)-III,(b)-I, (c)-IV,(d)-II  ii.(a)-II (b)-I,(c) -IV,(d)-III

iii.(a)-II,(b)-III,(c)-IV,(d)-I iv. (a)-III, (b)-IV,(c)-I,(d)-II

• Types of Joints — Extent of Movement
  • (a) Ball and socket joint — I. Allows movement only in one direction
  • (b) Hinge joint — II. Allows rotatory movement around a single axis
  • (c) Gliding joint — III. Allows maximum movement in all directions
  • (d) Pivot joint — IV. Allows little movement in all directions
• Answer: i. (a)-III, (b)-I, (c)-IV, (d)-II

c.The part labelled as Xindicates the:

1. Fibula ii. femur iii. tarsal iv. tibia

Answer: ii. femur

d. Anita touched her outer ear and felt no hard bony parts. This is because the outer ear is made up of

   i. joints ii. ligaments iii. cartilages iv. bones

Answer: iii. cartilages

Q2. Assertion -Reasoning questions

For question number (i) and (ii) ,two statements are given -one labelled as assertion(A) and the other labelled as Reason ( R ). Select the correct answer to these questions From the codes (a), (b),(c) and (d) is given below.

• Both assertion(A) and Reason (R) are true  and Reason (R) is the correct explanation of the assertation (A)
• Both assertion (A) and reason are true and Reason (R) is not the correct explanation of the assertation (A)
• Assertion (A) is true but reason (R) is false
• Assertion (A) is false, but reason (R) is true.
• Assertion(A) : The bodies of birds have streamlined shapes.

Reason(R)    : The streamlined shape helps to reduce the resistance of air while flying

Answer: (a) Both assertion (A) and reason (R) are true, and reason (R) is the correct explanation of assertion (A).

• Assertion (A): A fish have a special structure called swim bladder.

Reason (R)    : Fish can fill the swim bladder or empty it to help[ them move up and down in water.

• Answer: (a) Both assertion (A) and reason (R) are true, and reason (R) is the correct explanation of assertion (A).

 Q3. Answer the following question in one sentence.

• A special structure present behind a cockroach’s body helps it to sense any danger from behind what are these structures called?

Answer: These structures are called cerci.

• State the importance of lower tentacles in snails.

Answer: The lower tentacles in snails help them to feel their way around and sense the ground.

• What are joints?

Answer: Joints are places where two bones meet and allow movement of different body parts.

Q4. Answer the following question in 2-3 sentences.

• Which ribs are called floating ribs?  Why are they called so?

Answer: The last two pairs of ribs in humans are called floating ribs. They are called floating ribs because they are not attached to the breastbone or sternum at the front of the body.

• We can see the bones clearly in X ray image Give two reasons to support this statement

      Answer: First, bones are denser than other body tissues, so they block more X-ray beams, making them appear white on an X-ray image. Second, X-rays pass more easily through soft tissues, making bones stand out clearly in the image.

Q5. Answer the following questions in 3-4 sentences.

1. Explain the terms ‘Upstroke’ and ‘downstroke’ with respect to the flying movement in birds.

Answer: In birds, the “upstroke” is when the wings move upwards to prepare for the next flap. During the upstroke, the wings fold slightly to reduce resistance. The “downstroke” is when the wings push down strongly, creating lift to help the bird fly. This up-and-down motion allows birds to stay in the air.

• Cockroach is an insect.
• What is the hard outer skeleton of a cockroach called?

Answer: The hard outer skeleton of a cockroach is called an exoskeleton.

• What is the function of antennae in cockroach?

Answer: The antennae help the cockroach sense its surroundings and detect food and danger.

• How many pairs of legs does a cockroach have?

Answer: A cockroach has three pairs of legs