Samacheer Kalvi Class 8 Science Unit 19 Movements in Animals Solutions
Welcome to NCTB Solutions. Here with this post we are going to help 8th class students by providing Solutions for Samacheer Kalvi Class 8 Science Unit 19 Movements in Animals. Here students can easily find all the solved solution for Movements in Animals Exercise questions. Also here our Expert Science Teacher’s solved all the questions with easily understandable language with proper guidance so that all the students can understand easily. Here on this post students will get Unit 19 Movements in Animals exercise solutions. Here all the solutions are based on Tamil Nadu State Board latest syllabus.
Unit 19 Movements in Animals Exercise Questions Solutions :
(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 option below.
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (iv)
(d) (iii) and (ii)
Answer :
Correct Option → (a)
Bones and Muscles help us in movement.
(2) Which one of the following organisms lack muscles and skeletons for movements
(a) Dog
(b) Snail
(c) Earth worm
(d) Human being
Answer :
Correct Option → (b)
Snail are the organisms who lack muscles and skeletons for movements.
(3) __ joints are immovable
(a) Shoulder and arm
(b) Knee and joint
(c) Upper jaw and skull
(d) Lower jaw and upper jaw
Answer :
Correct Option → (d)
Lower jaw and upper jaw joints are immovable.
(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
Answer :
Correct Option → (a)
Underwater divers wear fin like flippers on their feet because of this they swim easily in water.
(5) Your external ear(pinna) is supported by
(a) Bone
(b) Cartilage
(c) Tendon
(d) Capsule
Answer :
Correct Option → (b)
External ear or pinna is supported by Cartilage.
(6) Cockroach moves with the help of its
(a) Legs
(b) Bone
(c) Muscular foot
(d) Whole body
Answer :
Correct Option → (a)
Cockroach moves with the help of its Legs.
(7) Which one of the following categories of vertebrae are correctly numbered
(a) Cervical-7
(b) Thoracic-10
(c) Lumbar-4
(d) Sacral-4
Answer :
Correct Option → (a)
Correctly numbered categories of vertebrae is Cervical-7
(II) Fill in the blanks
(1) Movement of organisms from place to place is called ___
(2) ___ refers to change in position of the part of an organism’s body.
(3) A structure which provides rigid frame work to the body is called ___
(4) Axil skeleton in human consists of ___,___ and ___
(5) Appendicular skeleton in human consists of ___ and ___
(6) The place where two bones meet is termed as ___
(7) ___ is attached to soft parts of the body like blood vessels, iris, bronchi and the skin
(8) ___ muscle makes pupil of eyes wider.
Answer :
(1) → Locomotion
(2) → Movements
(3) → Skeleton
(4) → Skull, facial bones and vertebral column
(5) → Pectoral griddle and Pelvic bone
(6) → Joints
(7) → Involuntary muscle
(8) → Radial muscle.
(III) State true or false. If false, correct the statement.
(1) Skull in humans consists of 22 bones.
(2) There are 12 pairs of ribs in human body.
(3) Pelvic girdle is a part of axial skeleton.
(4) Hinge joint is slightly movable joint.
(5) Cardiac muscle is a voluntary muscle.
(6) The flexor and extensor muscle of the arm are antagonistic muscles.
Answer :
(1) → True
(2) → True
(3) → False.
Because, it is a part of the appendicular skeleton
(4) → False,
Because, hinge joint is the freely movable joint.
(5) → False,
Because, it is involuntary muscles.
(6) → True
(IV) Answer very briefly
(1) What is skeleton?
Answer :
The skeleton it is the system which provides the hard structure or framework to the human body which supports and protects the body.
(2) What is cranium?
Answer :
Cranium is the part of the skull.
(3) Why our backbone is slightly moveable?
Answer :
The backbone is silghlty movable because body to be allow to bent front and back. therefore it is slightly movable.
(4) Differentiate axial and appendicular skeleton.
Answer :
| Axial skeleton : | Appendicular skeleton : |
| (1) The axial skeleton consist of the bones along the axial or central line of the human body. | (1) The appendicular skeleton constains the bones in the appendages of the body and and the structures that connect to appendages to the aixial skeleton. |
| (2) It contains skull, ribs and sternum and vertebral column. | (2) It contains pectoral girdle, pelvic girdle. |
(5) What is ligament?
Answer :
Ligament is the band of strong tissue.
(6) Define muscle.
Answer :
Muscles are the fibrous tissue in the body which provide the skeletal framework and also give shape to the body.
(7) Differentiate tendons and ligament.
Answer :
• Tendons :
Tendons are the fibrous cords of tissue that attach muscle to bone.
• Ligament :
Ligaments are the bands of the fibrous tissue attached to bone to bone.
(V) Answer briefly
(1) Differentiate between the following.
(a) Movement and Locomotion.
Answer :
| Movement : | Locomotion : |
| (i) Movement is the act of changing the place or position by one or more parts of the body. | (i) Locomotion is the movement of an organism from one place to another. |
| (ii) Movement can be either voluntary or involuntary | (ii) Locomotion is always voluntary |
| (iii) A movement can take place at the organism level. | (iii) Locomotion takes place at the organism level. |
| (iv) Movement requires energy. | (iv) Locomotion doesn’t require energy. |
(b) Endoskeleton and Exoskleton
Answer :
| Endoskeleton : | Exoskeleton : |
| (i) It is the skeleton which is found inside the human body. | (i) It is the skeleton which found on the exterior layer of the human body |
| (ii) It is originates from the mesoderm. | (ii) It is originates from the embryonic ectoderm or mesoderm |
| (iii) These is found in almost all vertebrates and form the min body structure. | (iii) It is protects and preserves the inner organs and found in all types of animals. |
(c) Pectoral and Pelvic girdle
Answer :
| Pectoral bone | Pelvic bone |
| (i) It is also known as shoulder bone | (i) It is also known as pelvic girdle. |
| (ii) Shoulder bone is formed by collar bone at the front and the shoulder blade at the back. | (ii) It is made up of strong bones to balance entire weight of the body. |
| (iii) This bones are enclosed a socket cavity and forms a ball and socket joint. | (iii) Pelvic gridle is formed by five fused vertebrate at the back and form cavity in the centre. |
(d) Ball and socket Joint and hinge Joint
Answer :
- Ball and socket joint :
(A) A ball shaped head of one bone articulates with a cup like socket of an adjacent bone.
(B) Movement can occur in three planes this joint allows the greatest range of movement. For eg- shoulder, hip
- Hinge joint :
(A) A cylindrical protrusion of one bone articulates with a through shaped depression of an adjacent bone.
(B) Movement is restricted to one plane this joint allows bending and straightening only. For eg- elbow, knee and ankle.
(e) Voluntary and Involuntary muscle
Answer :
| Voluntary muscles | Involuntary muscles |
| (1) This muscles is also known as striated skeletal muscles. Located attachments in arms,legs neck. | (1) This muscles is also known as non striated or smooth muscles located attached to soft parts of the body like blood vessels. |
| (2) They are multinucleate ,unbranced and voluntary. | (2) They are single,central nucleus and involuntary. |
(2) What are antagonistic muscles? Give one example.
Answer :
Antagonistic muscles : Muscles often work in pairs which work against each other theses muscles is called as antagonistic muscles. Antagonistic muscles can be found all over the body. In the iris of the eye there are two sets of antagonistic muscles.
For example : antagonistic muscles are radial muscles which radiate from the pupil like spokes of bicycle and there are circular muscles.
(3) How is the skeleton of a bird well-suited for flying?
Answer :
The birds have streamlined body their bones are light and strong. The lower portion of limbs are modified as claws and help them walk and to perch. Birds have special flight muscles and the forelimbs are modified as wings. they shows two types of flight like gliding and flapping they flying with the help of wings. for performing different activities birds shows skeleton of this types and suited for flying.
(4) What are the functions of skeleton in human body?
Answer :
There are many functions of skeleton in human body are –
(a) It provides structure and shape to the body.
(b) It supports and surrounds the internal organs of the body.
(c) Calcium and phosphorous the two minerals that the body needs for important regulatory functions are stored inside the bones.
(d) The bones of the skeleton system act as levers for muscular action. The muscular movements are possible with tendons and ligaments
(e) This are the functions of skeleton in human body.
(VI) Answer in detail
(1) Name the different types of joints? Give one example for each type.
Answer :
| Types of joints : | Examples : |
| (1) Ball and socket joint | (1) Shoulder and hip |
| (2) Hinge joint | (2) Elbow, knee, ankle |
| (3) Pivot joint | (3) Spine (atlas /axis joint at the top) |
| (4) Condyloid joint | (4) Wrist |
| (5) Gliding | (5) Spine |
| (6) Saddle joint | (6) Thumb, shoulder and inner ear. |
(2) Write about the human axial skeleton, giving suitable labelled diagram.
Answer :
Axial skeleton : consists of the bones along the axis or central line of the human body. The skeleton consists of the skull, facial bones, sternum, ribs and vertebral column.
(a) Skull : it is hard structure made up of small bones. It is formed by 22 bones out of which 8 bones are fixed together to for cranium and 14 bones are fuse to form face.
(b) Vertebral column : it is the also known as backbone or spinal cord .it is trunk region to offer support to the upper part of the body. It is made of vertebrae. There are 7 cervial vertebrae,12 lumar vertebrae, 5 fused sacral and 3 fused coccygeal vertebrae. They protects spinal cord. And supports to head. It provides movement for the human skeleton.
(c) Sternum or rib cage : rib cage occupies the chest region. It is a cone shaped structure made up of 12 pairs of ribs. Ribs are attached to vertebrae at the back bone
(4) What is a streamlined body? How does it help in the movement of animals that fly or swim in water?
Answer :
A streamlined body is the shape of body of bird which help them to walk or swim on water surface. This body of birds and fishes is streamlined to reduce friction while moving in water. The birds and fishes have strong muscles which help in swimming. These type of body structure helps to fishes to move smoothly with the flow of water. Muscles and fins on the body and the rail help to keep the balance.
(5) Write a short note on different types of muscles.
Answer :
There are three different types of muscles :-
(a) Satiated or skeletal muscles or voluntary muscles : these type of muscles is located at attached to bones found in arms, legs and neck. They are multicleate, unbranced, voluenrty
(b) Non striated or smooth or involuntary muscles : these muscles located at the soft parts of the body like blood vessels, iris, bronchi and the skin. They are single, entral nucleus and involuntary.
(c) Cardiac muscles : they are found in heart or known as heart muscles. They have branched 1-3 central nuclei and involuntary muscles.
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