Important Questions for Class 11 Biology Chapter 18 Body Fluids

Very Short Answer Questions [1 Mark Questions]

Ques. RBC is nucleated in which mammal?

Ans. Camel’s red blood cells have a nucleus that is nucleated. The cells are oval in shape and not spherical. 

Ques. What do you mean by Systole?

Ans. The cardiac chamber has a contraction phase called the systole.

Ques. Which chamber of the human heart has the muscular wall the thickest?

Ans. The left ventricle has the thickest wall.

Ques. What do you mean by ECG techniques?

Ans. It is the technique used by heart surgeons for capturing and recording the numerous variations of the heart’s functioning and its working.

Ques. What is the location of the SA node?

Ans. SA-node is found at the merging place of sinus venous and at the side of the right wall in the right atrium.

Ques. Which granulocytes play an important role in detoxification?

Ans. In the process of detoxification, eosinophils play an important role.

Ques. What do you call a sphygmomanometer?

Ans. A sphygmomanometer is an instrument used to measure blood pressure. 

Ques. Which is also called the pacemaker of the heart and why?

Ans. The SA-node is self-excitatory and it makes the heart contract in a wave so it is also known as the pacemaker of the heart.

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Short Answer Questions [2 Marks Questions]

Ques. Differentiate between heart failure and heart attack.

Ans. 

Ques. What are the functions of the lymphatic system?

Ans. Its main functions are:

• It carries blood to the liver from the intestine
• It converts toxic ammonia into urea eliminated by the kidney
• Fibrinogen protein is made in the liver and is passed to the body through blood
• The liver absorbs excess glucose and fats present in the blood from the alimentary canal and is used when the body is under starvation.

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Ques. What happens in hemophilia?

Ans. It is a condition when a person has a slower process of blood clotting which results in a faulty clotting mechanism. It happens when the person’s blood lacks clotting enzymes and the person is at risk of blood loss because of injury. 

Ques. What are the types of granulocytes? Which constitutes the maximum percentage of leucocytes? Give a function. 

Ans. Granulocytes are of different types.

• Neutrophils which is 62%
• Acidophils which is 3%
• Basophils which are 0.5% to 1%

Ques. What are the important events of the cardiac cycle?

Ans. The cardiac cycle comprises three phases.

• Atrial systole
• Ventricular systole
• Joint diastole

Ques. Differentiate between Blood and Lymph. 

Ans. 

Ques. What are two sounds produced by the heart when it beats? Which is heard for a longer duration?

Ans. The two sounds produced by the heart when it beats are ‘Lubb’ and ‘Dupp’.

• ‘Lubb’ is the first sound heard when the AV valves close at the start of the ventricular systole.
• The sound ‘Dupp’ is produced by the closure of semilunar valves at the start of ventricular diastole. 

Among these two sounds, ‘Lubb’ is for a longer duration as it is caused by the sudden closure of the two valves. 

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Short Answer Question [3 Marks Questions]

Ques. Differentiate Left Ventricle and Right Ventricle.

Ans.

 

Ques. What is the necessity of thrombocytes for blood coagulation?

Ans. Coagulation of blood is an important feature required for fast recovery of any injury and prevent any blood loss. Thrombocytes and platelets help in the process of blood coagulation and due to thrombocytes, blood clotting takes place. 

These two coalesce together and help in coagulation. In simple terms, when the body faces any injury, the platelets are released with a clotting factor known as thromboplastin. They form blood clots and help in the faster recovery of an injury. This thromboplastin forms a network of fibrin around the platelets to make blood clots. Hence, thromboplastin is necessary fibrin for blood coagulation.

Ques. Differentiate between Arteries and Veins.

Ans. 

Ques. What do you mean by hypertension? What factors contribute to it?

Ans. Hypertension refers to an abnormal rise in arterial blood pressure. The factors which are responsible for hypertension are

• Nervous strain
• Renal disorder
• Hypercholesterolemia
• Arteriosclerosis

Ques. What chemical events take place during blood clots in order to seal the wound?

Ans. During the process of blood coagulation, some chemical events take place,

• When the blood comes out of the blood vessel, platelets are released and released platelets such as thromboplastin.
• Prothrombin is the starting point that converts prothrombin to thrombin.
• Thrombin helps in the conversion of fibrinogen to fibrin forming a network of blood cells.
• Ca++ions are necessary for the procedure. 

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Long Answer Questions [5 Marks Questions]

Ques. Discuss the Lymphatic System and its importance. 

Ans. A lymph is a colorless tissue that looks like blood but lacks hemoglobin and RBCs. Lymph has fewer blood proteins, has more waste matter, more food materials, and WBCs. The fluid is filtered from the walls of capillaries. The filtered tissue enters lymphatic capillaries and is sent to the lymph.

Lymph Circulation:

Lymph Vessels- Lymph vessels and capillaries are found in all organs of the human body. This lymph forms a network in the organs and it flows in these channels from organs to organs. There is two major lymph found in the human body:

• Ductus Thoracicus - It starts with dilatation in the abdominal cavity called receptaculum chyli. It is found in the lower extremities, abdominal region, left side of the thorax, pelvic area, head, and face.
• Lymph Nodes - These are small globular masses of tissues that are found in each region of the body.

Lymph Functions:

• Its main purpose is to send interstitial fluid to the bloodstream.
• It sends digested fat in the villi of the intestine through lacteals.

Also check: NCERT Solutions for Class 11 Biology

Ques. Show in graphical representations of double circulation in a human heart. Show with diagrams.

Ans. 

Ques. Discuss the events in the cardiac cycle and define double circulation.

Ans. The whole process of one heartbeat is called the cardiac cycle. One complete cycle of relaxation and contraction takes place which includes contraction and relaxation of the atria and ventricles. Some events taking place are

Atrial systole- The wave of contraction that takes place and is triggered by sino-atrial. The valves are open and blood is forced into the ventricles.

Beginning of systole(ventricular)- The wave of contraction by the AV node makes contraction of ventricles and thus leads to the valve to close and generate the sound ‘lub’ which is the first sound of a heartbeat.

Completing of systole- Blood flows into the trunk known as the pulmonary trunk. 

Beginning of ventricular diastole- The ventricles relax while the valves remain close and the sound ‘dub’ is heard which is the second sound of a heartbeat.

Completing of diastole- Due to pressure, blood flows from the atria to the ventricles. It does not flow backward due to the contraction of the heart and the pressure in the ventricles. 

Double Circulation- All mammals and birds have two pathways for blood. The left and the right atria are two pathways that receive and pass oxygenated and deoxygenated blood and pass through ventricles. This system is called double circulation. 

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