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VIII - SCIENCE - MOVEMENTS IN ANIMALS - EVALUATION - QUESTION - ANSWERS
MOVEMENTS IN ANIMALS
TEXTBOOK EXERCISES
I. Choose the best answer.
1. Which of the following parts of our body help us in movement?
(i) Bones (ii) Skin (iii) Muscles (iv) Organs
Choose the correct answer from the options below.
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (iv)
(d) (iii) and (ii)
Ans: (a) (i) and (iii)
2. Which one of the following organisms lack muscles and skeleton for movement?
(a) Dog
(b) Snail
(c) Earthworm
(d) Human being
Ans: (c) Earthworm
3. __________ joints are immovable.
(a) Shoulder and arm
(b) Knee and joint
(c) Upper jaw and skull
(d) Lower jaw and upper jaw
Ans: (c) Upper jaw and skull
4. Why do underwater divers wear fin-like flippers on their feet ?
(a) To swim easily in water.
(b) To look like a fish.
(c) To walk on water surface.
(d) To walk over the bottom of the sea (sea bed).
Ans: (a) To swim easily in water
5. External ear (pinna )is supported by
(a) bone
(b) cartilage
(c) tendon
(d) capsule
Ans: (b) cartilage
6. Cockroach moves with the help of its
(a) leg
(b) bone
(c) muscular foot
(d) whole body
Ans: (a) leg
7. Which one of the following categories of vertebrae are correctly numbered?
(a) Cervical-7
(b) Thoracic-10
(c) Lumbar - 4
(d) Sacral - 4
Ans: (a) Cervical-7
II. Fill in the blanks.
1. Movement of organisms from place to place is called __________.
Ans: locomotion
2. __________ refers to change in position of the part of an organism’s body.
Ans: Movement
3. A structure which provides rigid frame work to the body is called __________
Ans: skeleton
4. Axil skeleton in human consists of __________, __________, __________ and __________.
Ans: skull, ribs, sternum, and vertebral column
5. Appendicular skeleton in human consists of __________ and __________.
Ans: Pectoral Girdle and Pelvic Girdle
6. The place where two bones meet is termed as __________.
Ans: Joint
7. __________ is attached to soft parts of the body like blood vessels, iris, bronchi and the skin
Ans: Non striated muscle
8. __________ muscle makes pupil of eyes wider.
Ans: Radial
III. State true or false. If false, correct the statement.
1. Skull in humans consists of 22 bones.
Ans: True
2. There are 12 pairs of ribs in human body.
Ans: True
3. Pelvic girdle is a part of axial skeleton.
Ans: False
Pelvic girdle is a part of appendicular skeleton.
4. Hinge joint is slightly movable joint.
Ans: False
Hinge joint is freely movable joint.
5. Cardiac muscle is a voluntary muscle.
Ans: False
Cardiac muscle is an involuntary muscle.
6. The flexor and extensor muscle of the arm are antagonistic muscles.
Ans: True
IV. Answer very briefly.
1. What is skeleton?
The hard structure or framework which supports and protects the body is known as skeleton.
2. What is cranium?
The top portion of the skull, which protects the brain is called as cranium.
3. Why our backbone is slightly moveable?
Vertebral column running at the back of the body is called as spine or the backbone. Vertebral column is made up of individual bones called as vertebrae. Vertebrae are joined by gliding points which allow the body to be bent back, front or side wards.
4. Differentiate axial and appendicular skeleton.
5. What is ligament?
Ligaments are bands of tough, elastic connective tissue that surround a joint to give support and limit the joint's movement.
6. Define muscle.
A bundle of long muscle fibers that have the power to contract and hence to produce movement.
7. Differentiate tendons and ligament.
V. Answer briefly.
1. Differentiate between the following.
a) Movement and Locomotion.
b) Endoskeleton and Exoskeleton
c) Pectoral and Pelvic girdle
d) Ball and socket Joint and hinge Joint
e) Voluntary and Involuntary muscle
a) Movement and Locomotion.
b) Endoskeleton and Exoskeleton
c) Pectoral and Pelvic girdle
d) Ball and socket Joint and hinge Joint
e) Voluntary and Involuntary muscle
2. What are antagonistic muscles? Give one example.
A muscle that acts as the opposing force in contraction or relaxing of a muscle is called an antagonistic muscle.
Muscles often work in pairs which work against each other. These are called antagonistic pairs. Antagonistic muscles can be found all over the body.
Example: In the iris of the eye there are two sets of muscle.There are radial muscles which radiate from the pupil like spokes of a bicycle and there are circular muscles. The radial muscles make the pupil of the eye wider, while the circular muscles make the pupil smaller.
3. How is the skeleton of a bird well-suited for flying?
-A bird has a streamlined body.
-Its bones are light and strong. They are hollow and have air spaces between them.
-The breast bones are modified to hold massive flight muscles which help in moving wings up and down.
-Birds have special flight muscles and the forelimbs are modified as wings.
4. What are the functions of skeleton in human body?
The skeletal system serves five important functions in the human body.
i). It provides structure and shape to the body.
ii). It supports and surrounds the internal organs of the body.
iii). Calcium and phosphorus, the two minerals that the body needs for important regulatory functions, are stored inside the bones.
iv). Red blood cells are produced in the bone marrow.
v. The bones of the skeletal system act as levers for muscular action. Muscular movement would not be possible without tendons and ligaments.
VI. Answer in detail.
1. Name the different types of joints? Give one example for each type.
The point at which two separate bones meet is called a joint. Depending on the type of movement they allow, joints can be of three types: fixed, slightly movable and movable joints.
Fixed or Immovable joints:
In this type of joint no movement is possible between the two bones. The structures between the bones of the skull box are examples of immovable joints.
Slightly movable joints:
Here, only very little (partial) movement occurs between the two bones. The joint between a rib and the breastbone or between the vertebrae is the example for a slightly movable joint.
Freely movable joints:
In this type, varying degrees of movements is possible between the two bones forming the joint. There are six major types of movable joints.
They are given below;
2. Write about the human axial skeleton, giving suitable labelled diagram.
Axial skeleton:
The axial skeleton consists of the bones along the axis, or central line of the human body. The axial skeleton consists of the skull, facial bones, sternum, ribs, and vertebral column.
a. Skull
Skull is a hard structure made up of small bones.
It is formed by 22 bones out of which 8 bones are fixed together to form the cranium and 14 bones fuse to form the face.
The only bone which has a movable joint is the lower jaw.
b. Vertebral column:
Vertebral column running at the back of the body is also called spine or the backbone.
It is in the trunk region to offer support to the upper part of the body.
Vertebral column is made up of individual bones called vertebrae.
Total vertebral column consists of 7 cervical vertebrae, 12 lumbar vertebrae, 5 fused sacral and 3 fused coccygeal vertebrae.
Sternum or Rib cage:
Rib cage occupies the chest region. It is a cone-shaped structure made up of Twelve pairs of ribs.
Ribs are attached to vertebrae at the back which curve around to form a cage. Ten pairs of ribs are attached to the breast bone at the front.
Two pairs of lower ribs are free at front. These are called free-floating ribs.
Rib cage is set up in such a way that it can contract and expand during the process of breathing.
Rib cage protects the underlying lungs, heart and some parts of the liver.
3. Discuss various types of movements seen in living organisms.
There are three types of movements.
Amoeboid movement:
It is brought about by pseudopodia which are appendages which move with movement of protoplasm within a cell.
Ciliary movement:
This movement is brought about by appendages called as cilia which are the hairlike extensions of the epithelium. Both these kinds of movements are seen with cells of the lymphatic system.
Muscular movement:
It is a more complex movement which is brought about by the musculoskeletal system. This type of movement is seen in the higher vertebrates.
4. What is a streamlined body? How does it help in the movement of animals that fly or swim in water?
-A streamlined body is one which is pointed at the ends and broad in the middle.
-When such a body travels through air or water it exhibits minimum friction or resistance.
-A body shape which is streamlined helps cut against the friction created by the medium around the moving body.
-Streamlined body provides a smooth surface to an aquatic animal's body which reduces resistance in the water by reducing friction and makes movement easy.
-Minimum resistance in water increases the speed of the movement, and organisms move at a faster speed.
5. Write a short note on different types of muscles.
The muscles in the body provide the means of all movements.
Muscles found in higher vertebrates are of three types:
1. Striated or skeletal muscles or voluntary muscles.
2. Non Striated or smooth muscles or involuntary muscles
3. Cardiac muscles
