STD.6 (2015)
MOVEMENT IN THE BODY
Q.1 Define ‘Locomotion’.
When an organism moves from one place to another, it is termed as locomotion.
Ex.A jump, hop, walk and swim.
Q.2 Differentiate between movement and locomotion.
Movement
Locomotion
It is the change in the shape, direction etc. of
body parts.
It occurs when a body changes its position
from one place to another.
Plants show only movement no locomotion.
Animals show both movement and
locomotion.
Q.3 Which features of the Earthworm enable it to move on the ground? OR Explain the
movement in Earthworm.
Earthworm’s body is made up of many ring-like segments that have muscles.
These muscles help it to shorten and lengthen its body providing a push that helps the
body move forward.
In addition, the earthworm has special bristle like setae attached to the muscles. They
secrete a slimy substance which helps them to move easily.
Thus, repeated lengthening and shortening of body helps the earthworm move.
Q.4 How does slime help in movement of animals like earthworm and snail?
The earthworm has special bristle like setae attached to the muscles. They secrete a slimy substance
which helps them to move easily.
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Snail secretes a slimy substance known as mucous. It enables the snail to move with ease.
Q.5 Explain the Movement in Snail.
Snail has a slimy body without bones. It has a shell for protection. The snail moves with the
help of muscular organ known as the foot, which makes wave-like movements and secrete a
slimy substance known as mucous. It enables the snail to move with ease.
Q.6 Explain the Movement of Cockroach.
The body of cockroach is made up of head, thorax and abdomen. The thorax of cockroach
bears two pairs of wings and three pairs of jointed legs for movement. The cockroach has a
pair of sensitive antennae located at its head which helps the cockroach to sense and smell its
surroundings.
Q.7 What are the sensory structures in a snail and in a cockroach?
Snails have a pair of tentacles with eyes at the tips and a cockroach has a pair of antennae
located at its head. These sensory structures enable these animals to sense and smell the
surroundings.
Q.8 What is a streamlined body? How does it help in movement of animals that fly or
swim in water?
The body that is thicker in the middle and tapers at both ends, it is known as streamlined
body. This shape is known as streamlined body. This shape allows water to move easily
around the body and offers least resistance to its flow thus it helps the animal to swim.
This shape also helps the bird to fly as it makes it easy for them to move through the air. The
air can easily cut through the sides of the body and offers least resistance.
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Q. 9 Explain the special features which help fish to move in water.
The body of fish is specially designed for swimming.
It is stream lined i.e. thicker in the middle and tapers at both ends. This shape allows
water to move easily around the body and offers least resistance to its flow.
Fins of fish help in balancing and changing the directions.
It has swim-bladder, which is filled with air and keeps the fish afloat.
Tail movement from side to side propels the fish forward.
Q.10 Explain why the body of birds is well-suited for flight.
Most of the birds can fly. Birds can walk, hop, or run.
They have a streamlined body which makes it easy for them to move through the air.
The air can easily cut through the sides of the body and offers least resistance.
Bones of the birds are hollow which make the body light and fit for flying.
Forelimbs are modified to form wings for flight.
Feathers on their body keep them warm while flying at a height.
Strong chest muscles enable birds to flap their wings when flying.
Q.11 Explain the movement in Snake.
Snake has a long and strong backbone and the ribs. Snakes usually curve in a wave-like
motion and press against the ground with the help of scales to push forward. Thus, snake can
move fast in a wave like motion but not in a straight line.
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Q.12 Differentiate between exoskeleton and endoskeleton.
Exoskeleton
Endoskeleton
Hard part present outside the body forms
The bones are present within the body and
exoskeleton.
thus, form endoskeleton.
Ex. Scales, hair, horns
Ex. Bones, cartilage
Human beings:
The skeleton of a normal adult comprises of 206 bones.
Importance of the skeleton system:
a) It forms the framework of our body, provides shape and support and holds it upright.
b) It helps in the movement of various parts of the body.
c) It protects the internal organs of our body. Ex. Skull protects the brain, ribs protect the
heart and lungs.
d) Bones are filled with a spongy mass called the bone marrow where blood cells are formed.
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Skelton
Limbs
Skull
Backbone
or Spine
Rib Cage
Write a short note on:
a) Skull:
i) It comprises of the bones of the face and the head region.
ii) Most bones of the skull are fixed and cannot move except that of the lower jaw.
iii) The movement of the lower jaw makes it possible for us to chew food.
iv) The skull protects the brain which is an extremely vital organ of our body.
b) Rib Cage:
i) There are 12 pairs of ribs forming a cage-like structure called the rib cage.
ii) The ribs are flat, thin, curved bones that are joined with the backbone at the back and with
the breast bone in front.
iii) The last two pairs of ribs are not attached in front and are hence called floating ribs.
iv) The rib cage protects important organs such as the heart and lungs as well as parts of the
stomach and kidneys.
c) Backbone (Spine):
i) The backbone or spine is also known as vertebral column.
ii) It runs from the base of the skull to the lower back and forms the central supporting rod for
the skeleton.
iii) It is made up of 33 vertebrae that are joined to each other. Vertebrae are helpful in
bending and twisting our back.
iv) The backbone protects the spinal cord which arises at the base of our brain.
v) All animals that have a vertebral column are called vertebrates. Ex. Fish, reptiles, birds.
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d) Limbs:
i) There are two pairs of limbs – the fore limbs (arms) and the hind limbs (legs).
ii) The arm consists of the humerus, radius and ulna.
iii) The leg consists of the tibia and fibula bones. The thigh bone or femur is the longest bone
in our body.
iv) The pelvis (hip bone) supports the legs and attached to the lower end of the backbone.
v) Limbs allow us to perform various types of movements.
Q. 13 Explain the following terms:
A joint is a place where two bones are joined together.
A ligament is a tissue that joins two bones.
Cartilage is a tough, elastic, fibrous connective tissue that cushions bones at joints.
Muscles: Bundles of specialised cells that can contract or relax to create movement for the
body.
Tendon: Fibrous tissue that connects muscles to bones.
Synovial fluid: The space between two bones is filled with lubricating fluid called Synovial
fluid.
Q. 14 How do muscles help in movement?
Muscles are attached to the bones with the help of tendon and function by contracting and
relaxing. Muscles work in pairs. When we bend our arm, the muscles on the upper side
contract to pull bone up and at the same time the muscles on the lower side relax. Thus,
muscles help in movement.
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Joints are of two types: Movable and Immovable
Movable joints are categorised into four major types:
Hinge Joint
A movable joint that allows
movement in one direction
only.
Elbow Joint, Knee Joint and
Finger Joint
Ball and Socket Joint
A joint in which the round
end of a bone fits into the
cavity of another bone.
Shoulder and hip Joint
Pivot Joint
A joint in which movement is The joint where neck meets
limited to rotation.
the skull
Gliding Joint
A freely moving joint in
which the movement is
limited to gliding motions.
Ankle and Wrist Joint
Q.15 Mention the role of X-rays in the field of medicine.
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 bones. Thus, X-ray image is helpful
in case of a bone injury.
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