NCTB Class 7 Science Chapter 5 “Digestive System and Blood Circulation System” Solution
Bangladesh Board Class 7 Science Solution Chapter 5 “Digestive System and Blood Circulation System” Solution Exercises Question and Answer by Experienced Teacher.
NCTB Solution Class 7 Chapter 5 “Digestive System and Blood Circulation System”:
| Board | NCTB Bangladesh Board |
| Class | 7 |
| Subject | Science |
| Chapter | Five |
| Chapter Name | “Digestive System and Blood Circulation System” |
Fill in the blanks:-
(1) Enzymes help in—-.
Ans:- Digestion.
(2) In red blood cell—–a type of pigment is present.
Ans:- Haemoglobin.
(3) —–helps in blood clotting.
Ans:- Platelet.
(4) ——functions as security guard of the body.
Ans:- White blood corpuscle’s.
Short answered questions:-
(1) Ans:- Digested foods are absorbed in the last part of small intestine. Called ileum. In inner walls of ileum there is a absorption zone where are finger like projections in the wall called villi, by which the essential parts of food is absorbed.
(2) Ans:- We should brush and clean our teeth after every meal Because food particles that stick to the teeth gaps get rotten and operand bad breath which causes dental carries.
(3) Ans:- Foods enter into buccal cavity through mouth opening. After tasting, chewing and swallowing in buccal cavity the food materials move from buccal cavity to pharynx and from pharynx to oesophagus and at last from oesophagus to stomach.
(4) Ans:- The importance of blood cells in our body is, Blood cells contain fibrinogen that helps in clothing of blood.
(5) Ans:- The functions of blood vessels:
(a) Blood vessel (Arteries) transports oxygenate blood.
(b) Blood vessels through which blood from all over the body come back to the heart. (Veins)
Multiple choice questions:-
(1)Which one is the largest gland of the body?
Ans:- (d) Liver
(2) Which one is available in saliva?
Ans:- Ptyalin and water.
(3) Nucleus is absent in-
Ans:- (a) (i)
(4) Function of P is to-
Ans:- (b) (i) and (iii)
(5) Which one of following helps blood to clot?
Ans:- (b) N
Creative questions:-
(1) (a) Ans:- In ileum, there are finger like projection in the wall to perform the function of absorption is called villous.
(1) (b) Ans:- One should brush teeth after taking food because food particles that stick to the teeth gaps get rotten and spread bad breath which causes dental caries.
(1) (c) Ans:- Functions of ‘Y’ marked part are-
(a) Due to peristaltic movement of pharynx and oesophagus slimy foods are stored here.
(1) (d) Ans:- Digestive juices from its gastric glands help in digestion. When ‘z’ marked part is damaged then pain in the abdomen, stomach, digestive problems are arise in human body.
(2) (a) Ans:- Heart is covered with two layered thin membranes called pericardium.
(2) (b) Ans:- Lipase is a kind of enzyme which is produced in pancreas and it helps digesting fats and oils.
(2) (d) Ans:- We should take care of the organ in the stem to keep it healthy. Otherwise we have to face several problem like blood clots damage, breathing problems, pain in chest etc.
