Each point: 1 Mark
Transpiration is the process of loss of water as water vapour from the aerial parts of the plant.
Plants absorb minerals, nutrients, and water from the soil. All the water is not utilized by the plant. The excess water gets evaporated through the stomata present on the surface of the leaves by the process of transpiration.
This process also helps in cooling of the plants.
Each point: 1 Mark
ArteriesVeins1.Blood pressure in arteries is high1.Blood pressure in veins is low2.Arteries end in capillaries2.Veins start from capillaries3.Distributes blood to body organs.3.Collects blood from body organs
Location: 1 Mark
Chambers: 2 Marks
Blood circulation: 2 Marks
The heart is located in the chest cavity with its lower tip slightly tilted towards the left.
It has four chambers. The two upper chambers are called atria and the two lower chambers are called the ventricles.
The two types of blood circulation are pulmonary and the systemic circulation.
During the pulmonary circulation - The blood low in oxygen flows from the heart to the lungs and then oxygenated blood flows back to the heart. This blood rich in oxygen flows from heart to the rest of the body then back again to the heart. This is called systemic circulation.
Naming: 1 Mark
Functions: 4 Marks
There are three types of blood cells- Red blood cells/erythrocytes (RBC), White blood cells/leucocytes (WBC) and platelets.
Red blood cells (RBCs) contain a red pigment called haemoglobin. haemoglobin has two main functions.
1. Haemoglobin binds with oxygen and transports it to all the parts of the body.
2. The presence of haemoglobin makes blood appear red.
White blood cells(WBCs) help to fight against the germs that may enter into our body.
Platelets help in the clotting of blood and prevent bleeding and loss of blood.
Anwer the following questions: [5 MARKS]
1. Name the vessels which carry blood to the heart.
2. Name the vessels which carry blood away from the heart.
3. Name the blood vessel that brings oxygenated blood to the human heart.
4. Which chamber of the human heart receives deoxygenated blood?
5. Describe how deoxygenated blood from this chamber is sent to all parts of the body.
Each point: 1 Mark
1. Veins are the vessels which carry blood to the heart.
2. Arteries are the vessels which carry blood away from the heart.
3. Pulmonary vein is the blood vessel that brings oxygenated blood to the human heart.
4. Right chamber of the human heart comprising of right atrium and right ventricle receives deoxygenated blood from all the parts of the body.
5. De-oxygenated blood comes from the body to the upper chamber on the right, the right atrium, as it expands. Then it contracts to transfer the blood to the right ventricle causing it to dilate. The right ventricle, in turn, pumps it to the lungs for oxygenation which is brought back to left atrium by pulmonary vein. It is then pumped to the rest of the body by aorta.
Transpiration is defined as the process where plants expel excess water as water vapor through pores in their leaves called stomata. This process removes excess water, creates a suction pull to help in the transport of water upwards and cools down the plant. The phloem tissues help in the transport of food.