RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints

RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints are part of RBSE Solutions for Class 7 Science. Here we have given Rajasthan Board RBSE Class 7 Science Chapter 10 Skeleton and Joints.

Board RBSE
Textbook SIERT, Rajasthan
Class Class 7
Subject Science
Chapter Chapter 10
Chapter Name Skeleton and Joints
Number of Questions Solved 57
Category RBSE Solutions

Rajasthan Board RBSE Class 7 Science Chapter 10 Skeleton and Joints

Text book Exercise

Multiple Choice Questions :

Question 1.
What’s the longest middle section of Humerus is called?
(a) Shaft
(b) Girdle
(c) Joint
(d) Carpal
Answer:
(a) Shaft

Question 2.
Number of bones in thumb of hand.
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2

Fill in the blanks

(1) There are bones in our palm.
(2) Shoulder bone is called as
(3) Each finger of hand and leg has bones.
(4) Muscles have a capacity of and which help in movement.
Answer:

  1. five
  2. Pectoral girdle
  3. three
  4. contraction, expansion (relaxation).

Short answer type question

Question 1.
Tell about Radius-ulna bone.
Answer:
Radius and ulna are two bones of wrist of our hand. The first one towards the outside of arm and second one towards the inside the arm are respectively called radius and ulna. The end towards the elbow of this bone is attached to humerus and its lower end to wrist bones.

Question 2.
From which bones the front and back end of femur is articulated with?
Answer:
The lower end of femur is articulated with Tibia fibula and upper with hip bone.

Question 3.
Tell about pelvic and pectoral girdles.
Answer:
Shoulder bone is called pectoral girdle. Pectoral girdle is the set of bones in the perpendicular skeleton which connects to the arm on each side. The pelvic girdle (hip girdle) is formed by a single bone, the hip bone or coxal bone (coxal = “hip”), which serves as the attachment point for each lower limb. These two girdles are basis of our skeleton.

Question 4.
How many vertebrae are found in vertebral column?
Answer:
33 vertebrae are found in vertebral column.

Long Answer Type Question

Question 1.
What is a skeleton system? Draw a labeled diagram and describe functions of skeleton system?
Answer:
A frame work composed of bones and cartilage is called skeleton system. It makes frame work of our body. This skeletal system of the body performs the following important functions.
Functions of skeleton system:

  1. It provides framework and support to the body.
  2. Provides protection to body’s internal organs against external shocks.
  3. The skeleton system provides movement of body or parts of the body with the help of muscles.
  4. It strengthens the body.
    RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 1

Question 2.
What is a joint? Describe any two joints by a labeled diagram?
Answer:
The places at which the bones of the skeleton system are connected to each other are called joints.
(i) Ball and socket joint: In this type of joint one end of bone is cavity like and other remains rounded. The cavities called as socket and the rounded end as ball. Due to this particular structure of this joint. It is called as ball and socket joint.
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 2
In this joint round headed bone could easily turn around in all direction

Example

  1. Pectoral girdle and humerus.
  2. Pelvic girdle and femur.

(ii) In this joint: In this type of joint rounded end of a bone is implicated in the bone cavity of another.
Example
The joint at elbow and knee
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 3
Question 3.
What is a muscle? How do they help in movement? Describe by a labeled diagram?
Answer:
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 4
Muscles are made of contractile muscle fibre which has the ability to expand and contract.
For movement of any bone, two muscles work together. When a muscle contracts, bone is stretched in that direction and other muscle comes in a resting stage. For the movement of bone in opposite direction previous contracted muscle get loose and relaxed muscle shrinks. Both the type of muscles works simultaneously for body movement. Movement of bones is caused due to relaxation and contraction of muscles.

Activity

Question 1.
Prepare a list of bones of skeleton system on chart and demonstrate in a classroom.
Answer:

Part of Body Skeleton Region Name of bone and number Total number of bones of region Total number of bones
Head Skull Forehead Occipital: 1 Parietal: 2 Frontal: 1 Temporal: 2 Sphenoid: 1 Ethmoid: 1 8
face nasal: 2 mandible: 1 maxilla: (2) palatine: (2) zygomatic: (2) nasal bone: (2) lacrimal: (2) vomer: 1 14
ear malleus: (2) incus: (2) stapes: (2) 6
Hyoid Hyoid: 1 1 29
Vertical bone neck
chest
sacrum
cervical vertebrae: (7)
thoracic vertebrae: (12)
lumbar vertebrae: (5) sacral vertebrae: (1)
25 25
chest Sternum

Ribs

Sternum: 1
Ribs: 24
25 25
chest Pectoral girdle Scapula: 2 Clavicle: 2 4 4
pelvis hand pelvic girdle upper limb
fore limb
wrist
palm
fingers
innaminatus: 2
humems: 2
radius-ulna: 4
carpals: 16
metacarpal: 10
phalanges: 28
2

 

60

 

2

60

 

Legs thigh
calf
knee
ankle
foot
toes
femur: 2
tibia-fibula: 4
patella : 2
tarsals: 14
meta: tarsal -10
phalanges: 28
60 60

Question 2.
Prepare charts of diagrams of hand and leg’s bones.
Answer:
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 5
Question 3.
Demonstrate the mechanism of joints in a classroom.
Answer:
For this student can take bones made of plaster of paris in the laboratory and demonstrate the mechanism.

In Text Questions

Question 1.
What is a skeleton? (page 91)
Answer:
The Same work of body formed by bones, cartilages etc., is called skeleton.

Question 2.
Which are the main bones of skeleton system? (page 91)
Answer:
Main bones of skeleton system are skull bones, upper and lower jaw, bones of vertebral column, humerus, ulna, Tibia- fibula, femur etc.

Question 3.
Press the middle portion between elbow and shoulder. What did you experience? (page 92)
Answer:
Ahard and strong bone is felt. This bone is humerus.

Question 4.
To whom upper and lower end of humerus bone is attached? (page 92)
Answer:
Lower end is attached to radius ulna and upper end is attached to pectoral girdle.

Question 5.
Move hand along the knee to hips and experience its length. Also find out its position that where its upper and lower end is articulated? Based on this fill the below table: (page 93)
Answer:

S.No Questions related to touch experience

Probable answer

1 Position In between knee and hip
2 Length longest
3 Articulation of upper end pelvic girdle
4 Articulation of lower end Patella and TibiaFibula

Question 6.
Experience by touching the middle portion along the knee to ankle and with the help of figure, fill the following table: (page 94)

S.No Questions related to touch experience

Probable
answer

1 How many bones in this portion? 02
2 Where the upper end of these bones is articulated? Femur
3 Where the lower end of these bones is articulated? ankle bones

Answer:
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 6

Question 7.
Look at your ankle. Are you looking bones? (Page 95)
Answer:
Yes

Question 8.
Turn around your elbow and knee. Can they move circular? (Page 96)
Answer:
No, they can move in a single direction.

Question 9.
Turn around your head, what do you experience? (Page 96)
Answer:
It can move left right, top-bottom upto a certain direction.

Question 10.
What are muscles? (Page 97)
Answer:
Muscles are made of contractile muscle fibre which has the ability to expand and contract.

Other Important Questions

Multiple Choice Questions :

Question 1.
Skeletal system contains:
(a) bones
(b) cartilage
(c) joints
(d) all the above
Answer:
(d) all the above

Question 2.
Human skeletal system can be divided mainly into”
(a) two parts
(b) three parts
(c) four parts
(d) cannot be divided
Answer:
(b) three parts

Question 3.
The number of ribs in human body are:
(a) 6 pairs
(b) 9 pairs
(c) 12 pairs
(d) 24 pairs
Answer:
(c) 12 pairs

Question 4.
Bone of axial skeleton is:
(a) vertebrae
(b) humerus
(c) femur
(d) pelvic girdle
Answer:
(a) vertebrae

Question 5.
The number of bones in our one hand is
(a) 15
(b) 20
(c) 30
(d) 60
Answer:
(c) 30

Question 6.
Radius – Ulna is
(a) bone of skull
(b) bone of chest
(c) bone of hand
(d) bone of leg
Answer:
(c) bone of hand

Question 7.
Longest bone of our body is:
(a) vertebrae
(b) femur
(c) radius
(d) ribs
Answer:
(b) femur

Question 8.
Pectoral girdle is present in
(a) shoulder
(b) thigh
(c) pelvis
(d) stomach
Answer:
(a) shoulder

Question 9.
How many types of joints are there?
(a) two
(b) three
(c) four
(d) five
Answer:
(a) two

Question 10.
The bone found in our elbow is:
(a) pivot joint
(b) hinge joint
(c) immovable joint
(d) ball and socket joint
Answer:
(b) hinge joint

Fill in the blanks:

1. ………is the basic structure of our body.
2. Vertebral column is made of small ………… bones.
3. The long middle portion of humerus is called ………….
4. Ankle is made of total ……….. number of bones.
5. The movement of bones is due to contraction and relaxation of ……………..
Ans:

  1. Skeleton
  2. 33
  3. Shaft
  4. Seven
  5. Muscles

Very Short Answer Type Questions:

Question 1.
What are the three main parts of our skeletal system?
Answer:

  1. Axial skeleton
  2. Thoracic Skeleton
  3. Appendicular Skeleton.

Question 2.
How is back bone formed ?
Answer:
Back bone is formed by 33 small vertebrae.

Question 3.
What is other name for back bone?
Answer:
Vertebral column.

Question 4.
What is the main function of ribs?
Answer:
The body’s vital organs are heart, lungs, etc., are protected by ribs.

Question 5.
Which bones are included in Appendicular skeleton?
Answer:
Pectoral girdle, pelvic girdle, bones of hands and legs.

Question 6.
What is a wrist?
Answer:
The place where radius ulna bone is attached to palm is called wrist.

Question 7.
What are the bones of fingers called?
Answer:
The bones of fingers are called carpals.

Question 8.
Write the name of two main type of joints.
Answer:
(a) Movable joint and
(b) Immovable joint

Short Answer Type Questions:

Question 1.
Classify skeleton found in humans.
Answer:
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 7

Question 2.
Write the name of bones of hand.
Answer:

  1. Humerus
  2. Radius Ulna
  3. Carpals,
  4. Metacarpal
  5. Phalanges.

Question 3.
Describe bones of palm, fingers and thumb.
Answer:
There are five bones in palm. Our fingers and thumb also have bones which is called carpals and thumb bones respectively. Each bone has three bones and thumb has two.

Question 4.
Write the name of main bones of leg.
Answer:

  1. Femur
  2. Tibia – Fibula
  3. Patella
  4. Tarsals
  5. Meta-tarsal
  6. Phalanges.

Question 5.
Describe in brief bones of legs.
Answer:
The long bone from pectoral girdle to knee is called femur. It is the longest bone of the body. Tibia fibula is found between ankle and the knee. It consists of two bones tibia and fibula. Tibia is located inside and fibula towards the outside. Ankle consists of seven bones which form heels. Foot have five bones called the meta-tarsals. There are three bones in each finger of leg and two in toe.

Question 6.
Describe pivot joint with diagram
Answer:
The joint by which our head is articulated with upper end of the spine is called pivot joint. Due to this joint the lower end of the skull turn around easily left, up-down on stable bone of vertebral column.
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 8

Long Answer Type Questions:

Question 1.
Draw a table of name and number of bones found in hand.
Answer:

S.No Name of parts of hand Name of bone Number of bones
1 From elbow to shoulder bone (above the elbow) Humerus 01
2 From elbow to wrist (from elbow downward) Radius (outside the body) Ulna (body inwards) 02
3 Wrist bones Carpals 08
4 Palm bones Meta
carpals
05
5 Finger bones Carpals 03×4=12
6 Thumb (hand) bones Thumb
bone
02

Question 2.
Draw a table of names and number of bones found in different parts of leg.
Answer:

S.No. Name of the part of leg Name of Bone Number of bones
1 Thebone between the knee and hip Femur 01
2 The bone between the knee and ankle

Tibia
fibula,
patella

02+01
3 Ankle bone Tarsals 07
4 Bones of foot Meta
tarsals
05
5 Bones of foot fingers Phalanges 12
6 Bones of toe Phalanges 02

Question 3.
How movement takes place in Earthworm, snail, cockroach, bird, fish and snake.
Answer:

S. No. Animal Name Type of movement Helpful in movement
1 Earthworm Creep Earthworm moves by expansion and contraction of muscles of the body
2 Snail Creep Snail creeps and moves with muscular foot
3 Cockroach Walk/Fly In cockroaches the body and legs are covered with hard cover. The thoracic muscles are attached to the three pairs of legs and two pairs of wings who help cockroaches in flying and walking by which he moves from one place to another
4 Bird Fly/Walk In birds muscles are firm and bones are hollow due to which they are lighter. Both of them (muscles and bones) together help birds in flying.
5 Fish Swim Fish is a linear in shape. Annuluses are formed on both the side of its body due to movement of muscles. As a result fish moves by swimming in the water.
6 Snake Creep Snake creep on the ground by making rings in alternate order on both the side of its body. Several bones and its associated muscles push the body forwards that the snake is in motion.

Question 4.
Write a short note on Jaipur foot. disabled, suggested to Shri Ram Chandra Sharma
Answer:
Jaipur Foot is also known as Jaipur leg. It is for making worn down the knee. It is prepared by the high quality rubber. Dr.P.K.Sethi of Sawai Man Singh Hospital, Jaipur (India) perceived problems of the disabled by fitting Jaipur. Bhagwan Mahaveer Viklang Sahayata Samiti established by Devendra Raj Mehta help the disabled by fitting Jaipur foot free of charge to needy persons
RBSE Solutions for Class 7 Science Chapter 10 Skeleton and Joints 9
Jaipur foot related other information:

  • Jaipur foot works like a normal limb.
  •  It looks like a normal limb.
  • No adverse effect of water and moisture on it.
  • This shoe can be worn with or without shoes.
  • Generally a Jaipur Foot serves for three years.
  • It is very light in weight.

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