Class 7 Transportation in Animals
Short Answer Type Questions
1. What is blood? Write its two functions.
2. Write the functions of WBCs in our body.
3. What will happen if there are no platelets in the blood?
4. How many types of blood vessels are there? Name them.
5. What is a stethoscope? Explain its three parts.
6. Explain, why, the heart beats faster during and after an exercise?
7. What do you understand by ‘dialysis’? What type of patients are put on a dialysis machine?
8. Why are nephrons of human kidneys called filtering units?
9. What do you understand by translocation of food in plants? Explain briefly.
Answers: Short Answer Type Questions.
1. The blood is the main transport medium in human body. It is a fluid connective tissue and has two following functions
a. Urinary bladder.
b. The majority of oxygen in the body is transported by haemoglobin, which is found in red blood cells.
2. These are also called leukocytes. White blood cells protect the body from disease-causing organisms and fight infections.
3. Platelets are responsible for clotting of blood. If there are no platelets, the blood would not clot in case of an injury. This will lead to excess blood loss and finally in the death of the person.
4. The blood vessels are a kind of tubes (or pipes) through which the blood flows. There are three types of blood vessels in the body: arteries, veins and capillaries.
5. A doctor uses a stethoscope to listen to our heartbeats. The stethoscope amplifies (makes louder) the sound of heartbeats. So that the doctor can hear heartbeats clearly. A stethoscope consists of three parts:
(a) A chest piece that carries a sensitive diaphragm at its bottom.
(b) Two earpieces.
(c) A rubber tube which joins the chest piece to the earpieces.
6. When we do any physical activity like running and cycling, our heartbeat becomes faster. This is because, at such times, the body cells need more oxygen to release more energy through respiration. To supply more oxygen, the blood flows faster.
7. The process of cleaning the blood of a person (with kidney failure) by separating the toxic waste products, using a dialysis machine is called dialysis.
8. The nephrons act as filters and remove the harmful substances (urea, waste salts) from the blood. The waste products dissolved in water are removed from the kidney as a yellowish liquid called Urine.
9. The transportation of food from the leaves to other parts of the plant is called translocation. The translocation takes place with the help of the vascular tissue called phloem. Like xylem, phloem forms a continuous network
of channels that connect leaves to different parts of the plant. Through phloem, the prepared food passes from the leaves to different parts of the plant like stems, roots, fruits, seeds and flowers.