"Life Processes Class X Chapter One Solved Questions and Answers" Part-3

 Q.1. Name the system responsible for transportation of materials in human beings.
Answer: The system responsible for transportation of materials in human beings is circulatory system.
Q.2. List the various components of blood.

Answer: The various components of blood are:

1. Plasma 
2. Red blood cells (RBCs)
3. White blood cells (WBCs)
4. Platelets.

Q.3. Name the transport system in plants and animals.
Answer: Transport system in plants: Vascular strands ( xylem and phloem).
       Transport system in animals: circulatory system.
Q.4. Define the term 'translocation'.
Answer: The transport of photosynthetic products and other metabolites from one part to other parts of plants is termed as translocation.
Q.5. Name the four major chambers of the human heart.

Answer: The four major chambers of the human heart are:

1. Left atrium
2. Left ventricle
3. Right atrium
4. Right ventricle.

Q.6. What is double circulation?
Answer: Double circulation is a type of circulatory system found in mammals, in which the blood passes through the heart twice before completing a full circuit of the body. Blood is pumped from the heart to the lungs and returns to the heart before being distributed to the other organs.
Q.7. What makes red blood corpuscles red?
Answer: Red blood corpuscles (RBCs) contain red pigments haemoglobin which contains a red-coloured  compound heme, because of which blood looks red in colour.
Q.8. Name the conducting tissues of plants.
Answer: Xylem and Phloem.
Q.9. What is plasma?
Answer: Plasma is a fluid medium present in the blood in which cells are suspended.
Q.10. Name four kinds of cells (elements) of xylem.

Answer: Two kinds of cells (elements) of xylem are: 

1. Tracheids
2. Vessels.
3. Xylem parenchyma
4. Xylem fibres.

Q. 11. Name the blood vessels which carry blood from organs to the heart.
Answer: Veins.
Q.12. Name the blood vessels which carry blood from heart to the various organs.
Answer: Arteries.
Q.13. What is transpiration?
Answer: The loss of water from aerial parts of the plants in vapour form is known as transpiration.
Q.14. Name the tissue which transports water and minerals in a plant.
Answer: Xylem.
Q.15. Name the tissue which transports soluble products of photosynthesis in a plant.
Answer: Phloem.
Q.16. Name the process in plants where water is lost as water vapour.
Answer: Transpiration.
Q.17. What will happen to a plant if its xylem is removed?
Answer: If a plant's xylem is removed from the plant, the plant will not be able to transports water and mineral  from the roots to the other parts of the plant  and the plant will eventually die.
Q.18. What is sphygmomanometer? What is its purpose?
Answer: A sphygmomanometer is an instrument used to measure blood pressure.
      The purpose of sphygmomanometer is to measure the pressure of the blood within the arteries.
Q.19. Point out differences between an artery and a vein.

Answer: 

1. Arteries carry blood away from the heart to various organs whereas veins carry blood from different organs to the heart.
2. Arteries carry oxygenated blood while veins carry deoxygenated blood.
3. Valves are absent in arteries whereas valves are present in veins.
4. Arteries have thick elastic walls while veins have thinner walls.

Q.20. Describe the mechanism of blood clotting.
Answer: Blood clotting involves participation of many substances (like calcium ions) commonly known as clotting factors or coagulation factors.

       The entire clotting process can be divided for convenience into following four basic stages:

1. Formation of enzyme thrombokinase (or thromboplastin) by the injured tissue cells and the platelets.
2. Thrombokinase and Ca++ convert the plasma protein prothrombin (formed by the liver) into enzyme thrombin.
3. The enzyme thrombin converts soluble fibrinogen into insoluble fibrin. Fibrin is a solid substance that forms thread. These microscopic threads of fibrin are sticky and form a network (mesh) at the wound.
4. The blood corpuscles get entangled in the mesh and together settle down as a clot or thrombus.

Q.21. Enumerate the functions of blood.

Answer: The functions of blood are-

1. Transport of nutrition: The nutrients vital for the energy, maintenance and growth of the body are transported via the blood.
2. Transport of respiratory gases: Transport of oxygen and carbon dioxide occurs via blood.
3. Transport of hormones and enzymes: Blood act as the medium for the transport of enzymes and hormones from their location to the site of action.
4. Removal of waste products: Blood helps in removal of waste product from the cells and tissues to the excretory glands such as kidneys, liver, lungs and skin.
5. Clotting of blood: Loss of blood cells and body fluids is prevented via clotting of blood.
6. Maintain body temperature: Blood helps to maintain haemostasis of the body and thus regulates the body temperature.
7. Defensive action: WBCs (white blood cells) present in blood help the body to fight any infections and injuries caused by a foreign body.
8. Regulates blood pressure: Blood also helps to regulate the blood pressure in the body.

Q.22. Describe the structure of human heart very briefly.
Answer: The human heart is conical in shape with a size of our fist. It has four chambers: the right atrium, left atrium, right ventricle and left ventricle. The upper chambers are called atria and the lower chambers are called ventricles. There are valves between left atrium and left ventricle and between right atrium and right ventricles. These valves provide one-way passage, i.e. blood can only flow from atrium to ventricles.
Q.23. What is clotting or coagulation?
Answer: The process of clot formation at the site of blood loss from the body is called clotting or coagulation.
Q.24. Why clotting or coagulation is important?
Answer: Clotting of blood prevents further loss of blood and entry of pathogenic microorganisms.
Q.25. Write the functions of lymph.

Answer: The functions of lymph are as follows:

1. It carries digested and absorbed fat from the intestine.
2. It drains the excess fluid from extra cellular space back into the blood.

Q.26. Write the importance of transpiration.

Answer: Importance of transpiration are:

1. It helps in the absorption and upward movement of water and minerals dissolved in it from roots to the leaves.
2. It also helps in temperature regulation.

Q.27. What is systolic and diastolic pressure? Write the normal systolic and diastolic pressure in human beings.
Answer: Systolic pressure is the pressure of blood inside the artery during ventricular contraction. The normal systolic pressure is about 120 mm of Hg.
          Diastolic pressure is the pressure of blood inside the artery during ventricular relaxation. The normal diastolic pressure is about 80 mm of Hg.
Q.28. What causes hypertension?

Answer: Hypertension is caused by the constriction of arterioles which results in increased resistance to blood flow.