1. Q & A – MOVEMENTS IN THE BODY

2. Section E : Answer the following questions in brief
Section E : Answer the following questions in brief. Q1) Differentiate between movement and locomotion. Ans. An organism moving its body parts without changing its place shows movement where as an organism moving from one place to another is termed as locomotion. Q2) Which features of the earthworm enable it to move on the ground? Ans. The ring like segments having muscles, setae, and the slimy substance enables an earthworm to move on the ground.

3. Q3) How does slime help in movement of animals like earthworm and snail?
Ans. The slime is produced in order to aid locomotion by reducing friction. The slime also reduces the risk of injury and helps to keep away potentially dangerous insects like ants.
Q4) What are the sensory structures in a snail and in a cockroach?
Ans. The sensory structure in a snail is the tentacles and that in a cockroach is the antennae.

4. Q5) What is a streamlined body
Q5) What is a streamlined body? How does it help in movement of animals that fly or swim in water. Ans. The shape of the body that is thicker in the middle and tapers at both ends is known as a streamlined body. This shape allows water to move easily around the body and offers least resistance to its flow for animals that swim in water. This shape also allows air to easily cut through the sides of the body and offers least air resistance for animals that fly.

5. Section F : Answer the following questions in detail
Section F : Answer the following questions in detail. Q1) How is movement brought about in the following organisms? A. Earthworm B. Snail C. Cockroach Ans. Earthworms move by contacting and relaxing the muscles of their body and adhering to the ground with the help of setae. They secrete a slimy substance which helps them to move easily. The Snail moves with the help of a muscular organ known as the foot which makes wave-like movements and secretes mucous that enables the snail to move with ease. Cockroaches possess 3 pair of jointed legs for moving and 2 pair of wings for flying. They walk in a very unique manner moving 3 legs at a time.

6. Q2) Explain why the body of birds is well-suited for flight. Ans
Q2) Explain why the body of birds is well-suited for flight? Ans. Birds have a streamlined body, which makes it easy for them to move through the air. The hollow bones make the body light in weight. The forelimbs are modified to form wings for flight. The chest muscles are very strong and enables birds to flap their wings when flying. The feathers keep them warm while flying at a height. All these features of birds are well suited for flight.

7. Q3) Differentiate between exoskeleton and endoskeleton
Q3) Differentiate between exoskeleton and endoskeleton. Give examples of organisms possessing these types of skeleton. Ans. The skeleton present externally in the body of an organism is known as exoskeleton whereas the skeleton present internally or within the body of an organism is known as endoskeleton. Endoskeleton is present in human beings, cats, dogs etc. Exoskeleton is present in cockroaches, insects, spiders etc.

8. Q4) Enumerate the functions of the skeletal system in our body. Ans
Q4) Enumerate the functions of the skeletal system in our body. Ans. The skeletal system has the following functions: 1. It forms the framework of our body, provides shape and support, and holds it upright. 2. It helps in the movement of various parts of the body. 3. It protects the internal organs of our body-the skull protects the brain, ribs protect the heart and lungs, back bone protects the spinal cord. 4. Bones are filled with a spongy mass called the bone marrow where blood cells are formed.

9. Q5) How do muscles help in movement. Explain in detail. Ans
Q5) How do muscles help in movement? Explain in detail. Ans. The muscles are attached to the bones with the help of a tissue called tendon and function by contracting and relaxing. Muscles work in pairs. For example, when we bend our arm, the muscles on the upper side contract or shorten to pull the bone up and at the same time the muscles on the lower side relax. When the arm is made straight again, the upper muscle relaxes while the lower one contracts.

10. Q6) What are floating ribs. Ans
Q6) What are floating ribs? Ans. The last two pairs of ribs in the rib cage are not attached to the breast bone at the front but are only attached to the back bone at the back. Hence these ribs are known as floating ribs. Q7) Describe with examples the four movable joints of our body. Ans. The 4 movable joints are hinge joint, ball and socket joint, pivot joint and gliding joint. Hinge Joint: These act like the hinges on a door to provide back and forth movement. They allow some rotation also. The finger and elbow joints as well as the knee are having hinge joint.

11. Ball & Socket Joint: At this joint, a ball like end of one bone fits into a corresponding cavity of another such that maximum movement including rotation can be made possible. Joints of the shoulder and hip are ball & socket joint. Pivot Joint: A pivot joint is a joint in which the ends of two bones meet – one end being a central bonny cylinder, the other end being a ring. The cylinder rotates inside the ring or the ring rotates around the cylinder. The joint where the neck meets the skull is a pivot joint. Gliding Joint: This kind of joint allows bones to glide over one another and provide a slight movement. These bones have flat ends and can move from side to side as well as back and forth. Ankle joints and wrist joints are gliding joints.

12. Q8) Mention the role of X-rays in the field of medicine. Ans
Q8) Mention the role of X-rays in the field of medicine. Ans. X-rays are special rays that can pass through the soft tissues but not through the bones. Hence, an image is created that reveals the nature of the bone. From an x-ray the doctor can identify the possibility of a bone injury.