digestive and excretory systems · 5. why do we need an excretory system ? ans:-we need an...
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[General Instruction: Students need to copy the question and answers in your school exercise book:]
Digestive And Excretory
Systems
EXERCISES:
118-05-2020
CLASS- IV, SCIENCE
CHAPTER- 3:-THEME-Human Body
EXERCISE FOR REVISION:-
A. Tick(√) the correct answers :-1. Where does the process of digestion start?
Ans:- (a) mouth.
2. _________ breakdown the starch present in food into sugar.
Ans:- (a) saliva.
3. Food passes from the mouth to the stomach through the ____________.
Ans:- (c) food pipe.
4. Which of the following organs produces bile that digests fats?
Ans:- (a) liver.
B. Fill in the blanks:-1. The breakdown of complex food into simple soluble substances that are absorbed by the body is called digestion.
2. The process of digestion completes in the small intestine.
3. The digested food is absorbed in the small intestine.
4. The large intestine holds undigested food, absorbs extra water and forms faeces.
5. Faeces are removed through the anus.
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EXERCISE FOR REVISION:-
A. Tick(√) the correct answers :-1. The process of removal of waste products formed in the body is called
Ans:- (b) excretion.
2. How many kidney(s) is /are present in humans?
Ans:- (b) 2.
3. Which of the following is not a healthy habit?
Ans:- (b) exercising just after meals.
B. Match the following:-1. Kidneys (b) form urine
2. Ureters (d) carry urine from kidneys to urinary bladder
3. Urinary bladder (a) stores urine
4. Urethra (c) removes urine from the body
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EXERCISE:-
SHORT ANSWER QUESTIONS:-
1. Name the organs of the digestive system.
Ans:- The organs of the digestive system are listed below:
a) Mouth
b) Food pipe
c) Stomach
d) Small Intestine
e) Liver and pancreas
f) Large Intestine
g) Anus
2. What is the function of saliva?
Ans:- Saliva is a digestive juice that get mixed with the chewed food in the mouth and breaks down the
starch or a complex carbohydrate that is present in the food into simple sugar (a simple carbohydrate). It
also makes the food soft and easy to swallow. The tongue helps in mixing saliva with the food.
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3. Write the functions of the Digestive system.
Ans:- The functions of the digestive system are given below:
(a) It breaks down the complex food into simple soluble substances that are absorbed by blood.
(b) It helps the body to absorb the necessary nutrients from the food, that are carbohydrates,
proteins, fats, vitamins, and minerals for performing different activities.
(c) It helps to eliminate the solid food waste out from our body.
4. Why should we chew food well?
Ans:- We should chew food well during eating because grinding and breaking the food into pieces by
using the teeth helps the saliva to get mixed with the chewed food easily. It also makes the food soft and
easier for swallowing.
5. Why do we need an excretory system ?
Ans:- We need an excretory system in our human body as it helps us to remove the harmful waste
products out from our body and also helps to maintain the water level of our body.
5TITHI BISWAS
RAKHI R. ROY 18-05-2020