Life Process || Heart || Blood || Red Blood Cells || White Blood Cells
1. Write down the main function of platelets.
Ans: The main function of blood platelets is to help in blood clotting in case of injury or wound in the body.
2. Write the composition of blood.
Ans: Blood is composed up of 55% plasma and 45% blood cells.
3. What are the main functions of blood?
Ans: There are mainly three functions of blood in human body. They are;
a) Transportation:
i) Blood takes oxygen from the lungs to the cells and tissues of the body. It brings carbon dioxide to lungs from different cells and tissue.
ii) Blood takes absorbed nutrients from the intestine to cells and tissues of the body.
b) Regulation:
i) It maintains the temperature of the body and keeps the body warm.
ii) It balances the quantity of water and different chemical substances in the tissues.
c) Protection:
i) Blood takes WBCs to the infected area of the body to fight against the diseases causing micro-organisms.
ii) Blood helps in rapid healing of wound and clotting of blood takes place from the wound or injury portion of the body.
4. What is anemia? What is the cause of it?
Ans: Anemia is a condition when a person’s body has fewer amount of red blood cells. If a person suffers from iron deficiency, less haemoglobin will be made and this will result in fewer red blood cells.
5. A man suffering from anemia feel tired in ashort walk. Give reason.
Ans: A man suffering from anemia cannot get large amount of oxygen and energy will not be produced sufficiently inside the body. Due to lack of energy the person feels tired even in short walk.
6. What is the total volume of blood pressure in a healthy adult person? What are the different components of blood?
Ans: 5.5 litres of blood is present in a healthy adult person. The main components of blood are plasma and three types of blood cells, viz. red blood cells, white blood cells and platelets.
7. What is a valve?
Ans: A valve is a small opening which does not allow the blood in opposite direction.
8. What is the name of the blood vessel which carries impure blood from heart to lungs?
Ans: Pulmonary artery carries impure blood from heart to lungs.
9. Define septum. Why does a wall separate the sides of heart?
Ans: The right and left chambers of the heart are separated by a muscular protion called septum.
The wall separates the two sides of heat. It is very important for warm blooded animals as they have high energy needed to maintain body temperature by cellular digestion.
10. What is the main function of aortic valve?
Ans: Aortic valve prevents the backward flow of the blood from the aorta to the left ventricle.
| Pulmonary Artery | Pulmonary Vein |
| It carries deoxygenated blood from heart to lungs. | It carries oxygenated blood from lungs to heart. |
| It is generated by semi lunar valves at its base in the heart. | It is not generated by valve. |
| It starts from right ventricle. | It starts from lungs. |
12. Differentiate between arteries and vein.
| Artery | Vein |
| Arteries carry pure blood except pulmonary artery. | Veins carry impure blood except pulmonary vein. |
| There are no valves in arteries. | The valves are present in veins. |
| Blood flows forcely in arteries. | Blood flows very slowly in veins. |
| It has a narrow lumen. | It has a wider lumen. |
13. Differentiate between auricles and ventricles.
| Auricles | Ventricles |
| Auricles are smaller than ventricles. | Ventricles are larger than auricles. |
| They are upper chambers. | They are lower chambers. |
| Veins are originated from auricles. | Arteries are originated from ventricles. |
| Auricles are thin walled chambers. | Ventricles are thick walled chambers. |