Living Science 2020 2021 Solutions for Class 6 Science Chapter 9 The Body And Its Movements are provided here with simple step-by-step explanations. These solutions for The Body And Its Movements are extremely popular among Class 6 students for Science The Body And Its Movements Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Living Science 2020 2021 Book of Class 6 Science Chapter 9 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Living Science 2020 2021 Solutions. All Living Science 2020 2021 Solutions for class Class 6 Science are prepared by experts and are 100% accurate.
Page No 96:
Question 1:
Is it possible for a single cell to perform all the activities necessary for life? If yes, in what kind of organisms?
Answer:
Yes, it is possible that a single cell performs all the activities required for life. The organisms in which a single cell performs all life activities are called unicellular organisms.
Page No 96:
Question 2:
Is an organ made up of only a single type of cell, or is it made up of different types of cells?
Answer:
An organ is made up of different types of cells. This is because every organ is composed of different tissues and every tissue is formed by a group of specific cells. Thus, organ as a whole is composed of different types of cells.
Page No 96:
Question 3:
Is digestion carried out by an organ or an organ system?
Answer:
The process of digestion is carried out by an organ system called digestive system. A digestive system is composed of different organs which aid in the completion of digestion.
Page No 96:
Question 4:
Name the organ system to which the brain belongs.
Answer:
Brain is a part of the nervous system. This system is responsible for controlling all the functions that occur in the body.
Page No 96:
Question 5:
Name the organ system in which the organs are different in males and females.
Answer:
The reproductive system is an organ system, which has different organs in case of males and females.
Page No 101:
Question 1:
List two important functions that your ribcage performs.
Answer:
The most important functions performed by the ribcage are as follows:
1. It helps in the protection of lungs and heart.
2. It also provides protection to the some parts of the kidneys and stomach.
Page No 101:
Question 2:
Blood cells are made in the skeletal system. In which part of the skeletal system are they made?
Answer:
The formation of blood cell takes place in the bone marrow. This bone marrow is present in the bones, which are part of the skeletal system.
Page No 101:
Question 3:
In which part of the skeletal system are almost all bones immovable?
Answer:
Almost all bones of the skull are immovable except for the lower jaw bone.
Page No 101:
Question 4:
Each bone in your backbone allows only slight movement. How then are you able to bend your back so much to touch your toes?
Answer:
The backbone is composed of 33 bones called vertebrae. Every single bone provides slight amount of movement. The combined effect of all 33 bones allows us to bend the back to touch our toes.
Page No 101:
Question 5:
Which joint allows greater movement−a hinge joint, or a ball and socket joint? What kind of movement do these joints allow?
Answer:
A ball and socket joint allows greater movement as compared to a hinge joint. A typical hinge joint allows movement in a single plane such as backward, forward, down and up movements. A ball and socket joint, on the other hand, allows movement in all directions such as rotational movements.
Page No 101:
Question 6:
Muscles make the bones move by pulling and pushing them. Do you agree? Give reasons.
Answer:
The given statement is false. This is because muscles can only pull the bones in one direction. However, muscles do not have the ability to push the bones. In order to facilitate bone movements, at least two sets of muscles are required, which can move the bones in opposite directions.
Page No 102:
Question 1:
Do all animals have bones? Give examples.
Answer:
Not every animal is composed of bones. Some of the animals that do not have bones in their structure are as follows:
1. Earthworm: The skeletal system of an earthworm is formed by liquid. The muscles of earthworm squeeze against the liquid material and help in the movement of earthworm.
2.Cockroach and snake: The bodies of cockroach and snakes are enclosed in a protective shell called exoskeleton. This exoskeleton is not made up of bones.
Page No 102:
Question 2:
Do the following have endoskeleton or exoskeleton−human, crab, cockroach, fish, snail?
Answer:
Humans and fishes have an endoskeleton composed of bones and muscles. Cockroach and crabs, on the other hand, have an exoskeleton, which encloses soft parts of the body.
Page No 102:
Question 3:
The fish uses the fins on its sides to paddle in water. Do you agree? Give reasons.
Answer:
No, fishes do not use the fins on their sides to paddle in water. The force required for the movement of the fish is generated by the tail fins that propel the fish in forward direction by pushing the water. Fins that are present the sides are primarily used for maintaining the balance during movement.
Page No 102:
Question 4:
How is movement in a snake related to the flexibility of its backbone? Is this also true for humans?
Answer:
The flexible backbone of the snake allows snake to curve its body into different loops. Every loop creates a forward push against the ground and help in the movement of snake. The flexibility of backbone is not entirely related to the movement of humans. This is because most of the movements in humans is controlled by the action of lower limbs.
Page No 103:
Question 1:
In which of these organ systems do the males and females have different organs?
(a) nervous system
(b) muscular system
(c) excretory system
(d) reproductive system
Answer:
(d) reproductive system.
The main organs of female reproductive system are ovaries, oviducts, uterus and vagina. The main organs of male reproductive system are testes, sperm tube, urethra and penis.
Page No 104:
Question 2:
Which of these has the least number of movable joints?
(a) skull
(b) backbone
(c) arms and hands
(d) legs and feet
Answer:
(a) skull.
The bones in the skull, except the lower jaw bone, do not allow any movement and hence, has the least number of movable joints.
Page No 104:
Question 3:
The hinge joints allow movement in
(a) all directions.
(b) one plane only.
(c) two planes only.
(d) depends on where the joint is located in the body.
Answer:
(b) one plane only.
The hinge joints allow movement in one plane only, that is up and down or backward and forward.
Page No 104:
Question 4:
The bones at the joints are held together by
(a) ligaments.
(b) cartilage.
(c) tendons.
(d) bone marrow.
Answer:
(a) Ligaments.
The bones at the joints are held together by strong, stretchy bands called ligaments.
Page No 104:
Question 5:
Which of these acts as a shock absorber at the joints?
(a) cartilage
(b) ligaments
(c) tendons
(d) biceps
Answer:
(a) cartilage.
The ends of the bones at the joints are covered with soft cartilage, which acts as a shock absorber, and reduces the friction between the bones.
Page No 104:
Question 6:
A group of cells specialized to perform a specific task is known as a/an
(a) tissue.
(b) organ.
(c) organ system.
(d) organism.
Answer:
(a) tissue.
A group of cells specialiazed to perform a specific task together is known as a tissue.
Page No 104:
Question 7:
Muscles in animals contract and expand for
(a) digestion of food.
(b) movement of body parts.
(c) breathing.
(d) all of these
Answer:
(d) all of these
Muscles in animals contract and expand for the movement of body parts, digestion of food and also for breathing.
Page No 104:
Question 8:
Which of these is not an organ system?
(a) heart
(b) respiratory
(c) digestive
(d) excretory
Answer:
(a) heart.
Heart is an organ, and not an organ system. It is one of the main organs in the circulatory system.
Page No 104:
Question 9:
Joints are places where
(a) two bones meet.
(b) two muscles meet.
(c) a bone and a muscle meet.
(d) all of these
Answer:
(a) Two bones meet.
The joints in the body are the places where two bones meet.
Page No 104:
Question 10:
Where is a hinge joint located in your body?
(a) between the arm and the shoulder
(b) between the upper and lower arms
(c) between the leg and the hip
(d) between the bones in the skull
Answer:
(b) between the upper and lower arms.
The hinge joint is located between the upper and lower arms in the body.
Page No 104:
Question 1:
All living organisms are made up of a number of cells. True or false?
Answer:
False. There are some organisms with single cell, which are called unicellular organisms, in which various life activities are carried out by the single cell.
Page No 104:
Question 2:
The main function of the __________ system is to transport nutrients, oxygen and waste.
Answer:
The main function of the circulatory system is to transport nutrients, oxygen and waste.
Page No 104:
Question 3:
The teeth are a part of the _____________ system.
Answer:
The teeth are a part of the digestive system.
Page No 104:
Question 4:
A child has more bone than an adult. True or false?
Answer:
True. A child has more bones than an adult. But as the child grows into an adult, many of the bones fuse together.
Page No 104:
Question 5:
Which part of the skeletal system is the brain protected by?
Answer:
The brain is protected by a hard, bony structure called the skull.
Page No 104:
Question 6:
How many movable bones does the skull have?
Answer:
The skull have one movable bone i.e., the lower jaw bone.
Page No 104:
Question 7:
Name two organs protected by the rib cage.
Answer:
The rib cage protects the heart and the lungs.
Page No 104:
Question 8:
Name the longest bone in the human body.
Answer:
The longest bone in the human body is the thigh bone or femur.
Page No 104:
Question 9:
The joints between the ribs and the breastbone allow slight movement. True or false?
Answer:
True. These kind of joints are categorised as slightly movable joints which is neither immovable nor freely movable.
Page No 104:
Question 10:
Name the group of muscles you use to lower your arm.
Answer:
The group of muscles used to lower the arm is called the triceps.
Page No 105:
Question 11:
Muscles move the bones by pulling and pushing them. True or false?
Answer:
False. Muscles cannot push bones, but can only pull them.
Page No 105:
Question 12:
Worms do not have bones. True or false?
Answer:
True. Worms do not have bones. They have liquid trapped in spaces inside the body. The muscles squeeze against the liquid, which keeps their body firm.
Page No 105:
Question 13:
What kind of skeleton does a cockroach have?
Answer:
A cockroach has an exoskeleton.
Page No 105:
Question 14:
Which fin of the fish helps it to move?
Answer:
The tail fin of the fish helps it to move.
Page No 105:
Question 15:
What is the shape that fish, birds, airplanes and ships have that reduces air/water resistance?
Answer:
The fish, birds, airplanes and ships have a streamlined body shape - rounded in front and narrow at the back. This reduces the air / water resistance.
Page No 105:
Question 16:
What is the name given to animals with backbone?
Answer:
The animals with backbone are called vertebrates.
Page No 105:
Question 1:
What is a tissue? Give two examples.
Answer:
A group of cells that performs a special job together is known as a tissue. Blood and bone are two examples of tissue.
Page No 105:
Question 2:
Name the main organs in the digestive system. What is the main function of this system?
Answer:
The main organs of the digestive system are teeth, food pipe, stomach, small intestine and large intestine. The digestive system of the body helps to digest and absorb the nutrients from food that are necessary for the growth and maintenance of the body.
Page No 105:
Question 3:
What is bone marrow? What is its main function?
Answer:
The soft spongy material found within long bones such as the femur is known as the bone marrow. Its main function is to produce new blood cells to replace ones that are damaged and worn out.
Page No 105:
Question 4:
What are the functions of the spine?
Answer:
The spine, or the backbone, is the supporting structure for the entire skeleton and it also protects the spinal cord.
Page No 105:
Question 5:
Why are at least two muscles needed to move a bone at a joint in one direction?
Answer:
Muscles can contract and pull on the bones, but they cannot push. Therefore, at least two muscles are needed. When one contracts, the other extends and vice-versa to allow movement at a joint.
Page No 105:
Question 6:
Name the three types of skeletons that living organisms have. Give one example of each.
Answer:
Living organisms have three type of skeletons:
- Endoskeleton : Example- skeletons in human beings.
- Exoskeleton : Example- snails.
- Liquid skeletons : Example- Earthworms.
Page No 105:
Question 7:
List two adaptations in birds that help them to fly.
Answer:
Birds have very strong muscles to help them fly. Further, they have hollow bones that reduces weight and makes flight easier.
Page No 105:
Question 1:
What is an organ system? Name three organ systems in the human body and their main functions.
Answer:
A group of organs working together to carry out life functions is an organ system.
Following are the three organs system in the human body:
(i) Circulatory system : Its main function is to transport nutrients, oxygen and waste to all parts of the body.
(ii) Nervous system : Its main function is to control all the functions of the body.
(iii) Respiratory system : Its main function is to take oxygen inside the body and to expel carbon dioxide from the body.
Page No 105:
Question 2:
How do the following move? a. earthworm b. snake c. fish
Answer:
(a) To move, the earth worm first extends the front part of its body, keeping the rear part fixed to the ground and shortens it , thus pulling the rear end forward. It carries out expansion and contraction of muscles repeatedly to move forward.
(b) A snake has a long, flexible back bone, which helps the snake to curve its body into many loops. Each loop pushes against the ground to propel the snake forward.
(c) A fish moves with the help of muscles that are found on either side of the backbone. These muscles contract on one side and expand on the other. This moves the body of a fish from side to side, in a zigzag pattern.
Page No 105:
Question 3:
Explain the structure of the ball and socket joint. Give two examples of such joints in the human body. What kind of movement does such a joint allow?
Answer:
A ball and socket joint allows movement in all directions. In such joints, the end of one of the bones is round like a ball. It fits into a hollow part (or socket) in the other bone. The bone that ends in a ball, can move in any direction.
Examples: Shoulder and hip joints.
Page No 105:
Question 4:
List the main functions of the human skeleton.
Answer:
The skeleton has following four main functions:
- Support: Our skeleton provides a hard framework to support the organs of body.
- Protection : The bones protect the soft organs in our body.
- Movement : They help in the movement of the body.
- Making blood cells : The inside of bones contains a soft substance , called bone marrow, where the blood cells are made.
Page No 105:
Question 5:
What is a joint? How can you classify joints on the basis of the movement they allow?
Answer:
A joint in the body is a place where two bones are joined together. A joint is strong enough to withstand jerks. The bones are held together at the joints by strong, elastic bands called ligaments.
The joints can be classified into following three types depending on the type of movement they allow:
(a) immovable,
(b) slightly movable, and
(c) freely movable.
Page No 105:
Question 6:
What is the difference between endoskeleton and exoskeleton? Give three examples of each.
Answer:
| Endoskeleton | Exoskeleton |
| The skeleton is present inside the body. | The skeleton is present outside the body. |
| This skeleton is made up of bones. | This skeleton is not made up of bones. |
| Examples: Human beings, birds and reptiles. | Examples: Snails, crabs and cockroaches. |
Page No 105:
Question 1:
What do you think would have happened if the backbone had only one long bone instead of many vertebrae?
Answer:
If the backbone had only one long bone instead of many vertebrae, then it was not possible for us to move, bend or twist our back. Our back would have been stiff and brittle.
Page No 105:
Question 2:
Fishes move by using their side fins as oars. Do you agree?
Answer:
No, the side fins on a fish only help in stability. The fish moves by alternately contracting and expanding muscles on the sides of its body. This causes the tail to move in a zig-zag manner and propels the fish through the water.
Page No 105:
Question 3:
The movements of some parts of your body are not within your control. Can you name two such parts?
Answer:
The movement of some parts of our body move without our conscious control. Such movements are known as involuntary movements. The blinking of eyes is an example of an involuntary movement. The movement of our diaphragms during breathing is also an example of an involuntary movement.
Page No 105:
Question 1:
Akram saw some children throwing stones at a dog. The dog would cry from pain when a stone hit it. Akram went up to the children and explained that it is wrong to cause pain to anyone in this way.
What value did Akram show?
Answer:
The response of Akram indicates that he is a caring and sensitive boy. He could sense the pain the dog was going through and decided to talk to the children. He was smart and pateint enough to talk to those children instead of scolding them or fighting with them.
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