Unit 1 class 4

Unit 1   class 4
1 What are organs?
ans The parts of body are called organs.
2 What is organ system?
Ans Organs combine and work together to form organ system.
3 Give example of organ system?
Ans Digestive system, circulatory system.
4 Write function of teeth?
Ans We use teeth to bite and chew food.
5 How many sets of teeth we have in our lives?

Ans We have two sets of teeth in our lives.
6 Write names of types of teeths?
Ans 1.Milk teeth 2.Parmanent teeth.
7 At what age milk teeth grow?
Ans Milk teeth grow at the age of three.
8 What is the no.of milk teeth?
Ans 20
9 When milk teeth start falling?
Ans milk teeth start falling at the age of 5or6.
10 At what age permanent teeth grow?
Ans At the age of 12 or 13
11 What is tooth decay?
Ans Tooth decay is disease of tooth that damages its structure.it is most important cause of tooth loss.
12 How many bones are present in our body?
Ans 206.
13 What are joints?
Ans A bone is joined to the next bone by a joint.the skeleton bends at joints.
14 Give examples of joints?
Ans Elbow joints ,knee joints
15 How can we move ?
Ans We can move with the help of skeleton.
16 What are muscles?
Ans Muscels are bundle of special type of cell.which have ability to contract and relax.
17 What is the functions of skeleton?
Ans 1).it protects our vital organs. Such as brain, heart  etc.            2)it gives shape to our body.        3).it allows us to move.
18 Write the name of longest bone in human body?
Ans Thigh bone.
19 Write the name of smallest bone in our body?
Ans Middle ear bone.
20 What is plaque?
Ans Sticky material formed on the theeth if not brushed properly.
21 What is skeleton?
Ans It is combination of bones to support the body.
22 What is stomach?
Ans The stomach is part of our digestive system.
23 What is ulcer?
Ans When people eat spicy food the wall of stomach may be damaged.in sevsere cases ,painful wound may develop which is called ulcer.
24 What is function of heart?
Ans It mumpes blood to all pats of body.
25 What is the function of lungs?
Ans They help us to get in oxygen and remove carbon dioxide.
26 What is brain?
Ans Brain controls all functions of our body.intelligence and memory are also due to the brain.
27 What is skull?
Ans The brain is well protected in a box of bones is called the skull.
28 What is the function of skin?
Ans It protects our body. It also helps to maintain temperature of the body.
29 How can we protect ourselves from diseases?
Ans We can stay safe by keeping our bodies and environment clean.
30 What are viruses
Ans Viruses are tiny living organisms.
31 Which germ cause malaria?
Ans Malaria is caused by a germ called plasmodium.
32 How dengue virus is transferred?
Ans Dengue virus is transferred by the biting of aedes mosquito.
33 Write symptoms of  dengue fever?
Ans Severe headache, pain in body, high fever, vomiting, bleeding from nose and gums.

 WRITTEN BY NARGIS PARVEEN