NEET AIPMT Biology Chapter Wise Solutions – Body Fluids and Circulation
Contents
NEET AIPMT Biology Chapter Wise SolutionsPhysicsChemistry
1. Which one of the following animals has two separate circulatory pathways? (AIPMT 2015)
(a) Whale
(b) Shark
(c) Frog
(d) Lizard
2. Doctors use stethoscope to hear the sounds produced during each cardiac cycle. The second sound is heard when (AIPMT 2015)
(a) AV node receives signal from SA node
(b) AV valves open up
(c) Ventricular walls vibrate due to gushing in of blood from atria
(d) Semilunar valves close down after the blood flows into vessels from ventricles.
3. Erythropoiesis starts in (AIPMT 2015, Cancelled)
(a) spleen
(b) red bone marrow
(c) kidney
(d) liver.
4. Which one of the following is correct? (AIPMT 2015, Cancelled)
(a) Lymph = Plasma + RBC + WBC
(b) Blood = Plasma + RBC + WBC + Platelets
(c) Plasma = Blood – Lymphocytes
(d) Serum = Blood + Fibrinogen
5. Blood pressure in the mammalian aorta is maximum during (AIPMT 2015, Cancelled)
(a) systole of the left ventricle
(b) diastole of the right atrium
(c) systole of the left atrium
(d) diastole of the right ventricle.
6. Person with blood group AB is considered as universal recipient because he has (AIPMT 2014)
(a) both A and B antigens op RBC but no antibodies in the plasma
(b) both A and B antibodies in the plasma
(c) no antigen on RBC and no antibody in the plasma
(d) both A and B antigens in the plasma but no antibodies.
7. How do parasympathetic neural signals affect the working of the heart? (AIPMT 2014)
(a) Reduce both heart rate and cardiac output.
(b) Heart rate is increased without affecting the cardiac output.
(c) Both heart rate and cardiac output increase.
(d) Heart rate decreases but cardiac output increases.
8. The given figure shows schematic plan of blood circulation in humans with labels A to D. Identify the label and give its functions? (NEET2013)
(a) C – Vena cava – takes blood from body parts to right auricle, PCO2 = 45 mm Hg
(b) D – Dorsal aorta – takes blood from heart to body parts, PO2 = 95 mm Hg
(c) A – Pulmonary vein – takes impure blood from body parts, PO2 = 60 mm Hg
(d) B – Pulmonary artery – takes blood from heart to lungs, PO2 = 90 mm Hg.
9. The diagram given here is the standard ECG of a normal person. The P-wave represents the (NEET 2013)
(a) beginning of the systole
(b) end of systole
(c) contraction of both the atria
(d) initiation of the ventricular contraction.
10. The figure shows blood circulation in humans with labels A to D. Select the option which gives correct identification of label and functions of the part. {Karnataka NEET 2013)
(a) B – Capillary-Thin without muscle layer and wall two cell layers thick
(b) C – Vein-Thin walled and blood flows in jerks-‘spurts
(c) D – Pulmonary vein-Takes oxygenated blood to heart. PQi = 95 mmHg
(d) A – Artery-Thick walled and blood flows evenly
11. The figure shows a human blood cell. Identify it and give its characteristics.
12. A certain road accident patient with unknown blood group needs immediate blood transfusion. His one doctor friend at once offers his blood. What was the blood group of the donor? (Prelims 2012)
(a) Blood group B
(b) Blood group AB
(c) Blood group O
(d) Blood group A.
13. Which one of the following human organs is often called the “graveyard” of RBCs? (Mains 2012)
(a) Gall bladder
(b) Kidney
(c) Spleen
(d) Liver.
14. ‘Bundle of His’ is a part of which one of the following organs in humans? (Prelims 2011)
(a) Brain
(b) Heart
(c) Kidney
(d) Pancreas
15. Which one of the following plasma proteins is involved in the coagulation of blood? (Prelims 2011)
(a) Albumin
(b) Serum amylase
(c) Globulin
(d) Fibrinogen
16. Arteries are best defined as the vessels which (Prelims 2011)
(a) supply oxygenated blood to the different organs
(b) carry blood away from the heart to different organs
(c) break up into capillaries which reunite to form a vein
(d) carry blood from one visceral organ to another visceral organ.
17. Which one of the following statements is correct regarding blood pressure? (Prelims 2011)
(a) 130/90 mm Hg is considered high and requires treatment.
(b) 100/55 mm Hg is considered an ideal blood pressure.
(c) 105/50 mm Hg makes one very active.
(d) 190/110 mm Hg may harm vital organs like brain and kidney.
18. A person with unknown blood group under ABO system, has suffered much blood loss in an accident and needs immediate blood transfusion. His friend who has valid certificate of his own blood type, offers for blood donation without delay. What would have been the type of blood group of the donor friend? (Prelims 2011)
(a) Type B
(b) Type AB
(c) Type O
(d) Type A
19. Given below is the ECG of a normal human. Which one of its components is correctly interpreted below? (Mains 2011)
(a) complex QRS – one complete pulse
(b) peak T – initiation of total cardiac contraction
(c) peak P and peak R together – systolic and diastolic blood pressures
(d) peak P- initiation of left atrial contraction only.
20. If due to some injury the chordae tendinae of the tricuspid valve of the human heart is partially non-functional, what will be the immediate effect? (Prelims 2010)
(a) The flow of blood into the aorta will be slowed down
(b) The ‘pacemaker’ will stop working
(c) The blood will tend to flow back into the left atrium
(d) The flow of blood into the pulmonary artery will be reduced.
21. Which two of the following changes (i -iv) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)? (Prelims 2010)
(i) Increase in red blood cell size
(ii) Increase in red blood cell production
(iii) Increased breathing rate
(iv) Increase in thrombocyte count. Changes occurring are
(a) (ii) and (iii)
(b) (iii) and (iv)
(c) (i) and (iv)
(d) (i) and (ii).
22. Fastest distribution of some injectible material/ medicine and with no risk of any kind can be achieved by injecting it into the (Mains 2010)
(a) muscles
(b) arteries
(c) veins
(d) lymph vessels
23. Given below are four statements (i-iv) regarding human blood circulatory system (Mains 2010)
(i) Arteries are thick-walled and have narrow lumen as compared to veins
(ii) Angina is acute chest pain when the blood circulation to the brain is reduced
(iii) Persons with blood group AB can donate blood to any person with any blood group under ABO system
(iv) Calcium ions play a very important role in blood clotting
Which two of the above statements are correct?
(a) (i) and (iv)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
24. The haemoglobin content per 100 ml of blood of a normal healthy human adult is (Mains 2010)
(a) 5 – 11 mg
(b) 25 – 30 mg
(c) 17-20 mg
(d) 12 – 16 mg
25. There is no DNA in (Prelims 2009)
(a) mature RBCs
(b) a mature spefmatozoan
(c) hair root
(d) an enucleated ovum
26. In a standard ECG which one of the following alphabets is the correct representation of the respective activity of the human heart? {Prelims 2009)
(a) S – start of systole
(b) T – end of diastole
(c) P – depolarisation of the atria
(d) R – repolarisation of ventricles
27. Globulins contained in human blood plasma are primarily involved in (Prelims 2009)
(a) osmotic balance of body fluids
(b) oxygen transport in the blood
(c) clotting of blood
(d) defence mechanisms of body.
28. Compared to blood our lymph has {Prelims 2009)
(a) plasma without proteins
(b) more WBCs and no RBCs
(c) more RBCs and less WBCs
(d) no plasma
29. In humans, blood passes from the post caval to the diastolic right atrium of heart due to {Prelims 2008)
(a) stimulation of the sino auricular node
(b) pressure difference between the post caval and atrium
(c) pushing open of the venous valves
(d) suction pull.
30. The most active phagocytic white blood cells are (Prelims 2008)
(a) eosinophils and lymphocytes
(b) neutrophils and monocytes
(c) neutrophils and eosinophils
(d) lymphocytes and macrophages.
31. Which type of white blood cells are concerned with the release of histamine and the natural anticoagulant heparin? (Prelims 2008)
(a) eosinophils
(b) monocytes
(c) neutrophils
(d) basophils.
32. A drop of each of the following, is placed separately on four slides. Which of them will not coagulate? (2007)
(a) blood serum
(b) sample from the thoracic duct of lymphatic system
(c) whole blood from pulmonary vein
(d) blood plasma.
33. Which one of the following has an open circulatory system? (2006)
(a) Octopus
(b) Pheretima
(c) Periplaneta
(d) Hirudinaria
34. You are required to draw blood from a patient and to keep it in a test tube for analysis of blood corpuscles and plasma. You are also provided with the following four types of test tubes. Which of these will you not use for the purpose? (2004)
(a) test tube containing calcium bicarbonate
(b) chilled test tube
(c) test tube containing heparin
(d) test tube containing sodium oxalate.
35. The cardiac pacemaker in a patient fails to function normally. The doctors find that an artificial pacemaker is to be grafted in him. It is likely that it will be grafted at the site of (2003)
(a) atrioventricular bundle
(b) Purkinje system
(c) sinuatrial node
(d) atrioventricular node.
36. Bundle of His is a network of (2003)
(a) muscle fibres distributed throughout the heart walls
(b) muscle fibres found only in the ventricle wall
(c) nerve fibres distributed in ventricles
(d) nerve fibres found throughout the heart
37. In the ABO system of blood groups, if both antigens are present but no antibody, the blood group of the individual would be (2003)
(a) B
(b) O
(c) AB
(d) A.
38. Impulse of heart beat originates frdm (2002)
(a) S.A. node
(b) A.V. node
(c) vagus nerve
(d) cardiac nerve.
39. Which of the following statements is true for lymph? (2002)
(a) WBC + serum
(b) blood – RBCs and some proteins
(c) RBCs + WBCs + plasma
(d) RBCs + proteins + platelets.
40. What is correct for blood group O? (2001)
(a) no antigens but both a and b antibodies are present
(b) A antigen and b antibody present
(c) antigen and antibody both absent
(d) A and B antigens and a, b, antibodies present.
41. Difference between pulmonary artery and pulmonary vein is that, the pulmonary artery has (2000)
(a) no endothelium
(b) valves
(c) thicker walls
(d) oxygenated blood.
42. In which point, pulmonary artery is different from pulmonary vein? (2000)
(a) its lumen is broad
(b) its wall is thick
(c) it has valves
(d) it does not possess endothelium.
43. Which statement is true for WBC? (2000)
(a) non-nucleated
(b) in deficiency, cancer is caused
(c) manufactured in thymus
(d) can squeeze through blood capillaries.
44. Rate of heart beat is determined by (1999)
(a) Purkinje fibres
(b) papillary muscles
(c) AV-node
(d) SA-node.
45. Which is the principal cation in the plasma of the blood? (1999)
(a) potassium
(b) magnesium
(c) calcium
(d) sodium.
46. The blood group, with antibody-A and antibody-B is (1999)
(a)O
(b)B
(c) A
(d) AB.
47. The thickening of walls of arteries is called (1999)
(a) arteriosclerosis
(b) arthritis
(c) aneurysm
(d) both (b) and (c).
48. An adult human with average health has systolic and diastolic pressures as (1998)
(a) 120 mm Hg and 80 mm Hg
(b) 50 mm Hg and 80 mm Hg
(c) 80 mm Hg and 80 mm Hg
(d) 70 mm Hg and 120 mm Hg.
49. Which of the following is not the main function of lymph glands? (1998)
(a) forming RBCs
(b) destroying bacteria
(c) forming WBCs
(d) forming antibodies.
50. Which of the following is agranulocyte? (1997)
(a) basophil
(b) neutrophil
(c) lymphocyte
(d) eosinophil.
51. The life span of human WBC is approximately (1997)
(a) between 2 to 3 months
(b) more than 4 months
(c) less than 10 days
(d) between 20 to 30 days.
52. The correct route through which pulse-making impulse travels in the heart is (1995)
53. The lymph serves to (1995)
(a) return the interstitial fluid to the blood
(b) return the WBCs and RBCs to the lymph nodes
(c) transport CO2 to the lungs
(d) transport O2 to the brain.
54. In veins, valves are present to check backward flow of blood flowing at (1995)
(a) atmospheric pressure
(b) high pressure
(c) low pressure
(d) all of these.
55. The neurogenic heart is the characteristic feature of (1995)
(a) humans
(b) arthropods
(c) rabbits
(d) rats.
56. The heart sound ‘dup’ is produced when (1994)
(a) mitral valve is closed
(b) semi-lunar valves at the base of aorta get closed
(c) tricuspid valve is opened
(d) mitral valve is opened.
57. The pace setter in the heart is called (1994)
(a) sino-atrial node (SAN)
(b) atrio-ventricular node (AVN)
(c) Purkinje fibres
(d) papillary muscle.
58. Blood capillaries are made of (1993)
(a) endothelium, connective tissue and muscle fibres
(b) endothelium and muscle fibres
(c) endothelium and connective tissue
(d) endothelium only.
59. Cells formed in bone marrow include (1992)
(a) RBC
(b) RBC and leucocytes
(c) leucocytes
(d) lymphocytes.
60. The genotype of B-group father of an O-group child is (1992)
(a) IO IO
(b) IB IB
(c) IA IB
(d) IO IB.
61. Component of blood responsible for producing antibodies is (1992)
(a) thrombocytes
(b) monocytes
(c) erythrocytes
(d) lympocytes.
62. Blood group AB has (1991)
(a) no antigen
(b) no antibody
(c) neither antigen nor antibody
(d) both antigen and antibody.
63. Carbonic anhydrase occurs in (1991)
(a) lymphocytes
(b) blood plasma
(c) RBC
(d) leucocytes.
64. Wall of blood capillary is formed of (1991)
(a) haemocytes
(b) parietal cells
(c) endothelial cells
(d) oxyntic cells.
65. Splenic artery arises from (1991)
(a) anterior mesenteric artery
(b) coeliac artery
(c) posterior mesenteric artery
(d) intestinal artery.
66. A vein possesses a large lumen because (1990)
(a) tunica media and tunica externa form a single coat
(b) tunica interna and tunica media form a single coat
(c) tunica interna, tunica media and tunica externa are thin
(d) tunica media is a thin coat.
67. Arteries carry oxygenated blood except (1989)
(a) pulmonary
(b) cardiac
(c) hepatic
(d) systemic.
68. Removal of calcium from freshly collected blood would (1989)
(a) cause delayed clotting
(b) prevent clotting
(c) cause immediate clotting
(d) prevent destruction of haemoglobin.
69. A person with blood group A requires blood. The blood group which can be given is (1989)
(a) A and B
(b) A and AB
(c) A and O
(d) A, B, AB and O.
70. Tricuspid valve is found in between (1989)
(a) sinus venosus and right auricle
(b) right auricle and right ventricle
(c) left ventricle and left auricle
(d) ventricle and aorta.
71. Lymph differs from blood in possessing (1989)
(a) only WBC
(b) more RBC and WBC
(c) more RBC and few WBC
(d) more WBC and few RBC.
72. Presence of RBC in urine is (1988)
(a) alkaptonuria
(b) urothiasis
(c) hematuria
(d) proteinuria.
73. Child death may occur in the marriage of (1988)
(a) Rht man and Rh woman
(b) Rh man and Rh woman
(c) Rh man and Rh woman
(d) Rh man and Rh woman.
74. Breakdown product of haemoglobin is (1988)
(a) bilirubin
(b) iron
(c) biliverdin
(d) calcium.
75. RBCs do not occur in (1988)
(a) frog
(b) cow
(c) camel
(d) cockroach.
EXPLANATIONS
1. (a)
Whale is a mammal and in mammals, two separate circulatory pathways are found — systemic circulation and pulmonary circulation. Oxygenated and deoxygenated bloods received by the left and right atria respectively pass on to the left and right ventricles. Thus, oxygenated and deoxygenated bloods are not mixed. This is referred to as double circulation. In shark (fish), the heart pumps out deoxygenated blood which is oxygenated by the gills and sent to the body parts from where deoxygenated blood is carried to the heart. It is called single circulation. In frog (amphibian)and lizard (reptile), the left atrium get oxygenated blood from the gills/ lungs/skin/ buccopharyngeal cavity and the right atrium receives the deoxygenated blood from other body parts. The oxygenated and deoxygenated bloods get mixed up in single ventricle which pumps out mixed blood. This is called incomplete double circulation.
2. (d)
Second heart sound i.e., dup is caused by the closure of the semilunar values and marks the end of ventricular systole.
3. (b)
Erythropoiesis is the formation of red blood cells (erythrocytes) which occurs in the red bone marrow. Proerythroblast is the earliest precursor which gives rise successively to the early erythroblast, intermediate erythroblast and late erythroblast. Then, the nucleus is forced out and a biconcave, enucleated cell called reticulocyte is formed, which is released into blood. In blood, it develops into mature erythrocytes.
4. (b)
Lymph = Plasma + WBC
Blood = Plasma + RBC + WBC + Platelets
Plasma = Blood – Cellular components
Serum = Plasma – Clotting factors
5. (a)
The temporary rise in blood pressure during the contraction of the heart is called systolic pressure and the temporary fall in blood pressure during relaxation of the heart is called diastolic pressure. Blood pressure is expressed as the ratio of the systolic pressure over the diastolic pressure. For a healthy resting adult person, the average systolic/diastolic pressures are 120/80 mm Hg. Aorta is directly supplied by left ventricle thus, the blood pressure in aorta is highest during systole ofleft ventricle. During it, left ventricle contracts and pushes blood into aorta.
6. (a)
ABO blood groups are determined by the gene I (isoagglutinin). There are three alleles, IA,IB and IO of this gene. IA allele is responsible for formation of A antigen, while IB allele is responsible for formation of B antigen. People with blood group A have the A antigen on the surface of their RBCs, and antibodies to antigen B in their plasma. Persons with blood group B have B antigen on their RBCs, and antibodies against A antigen in their plasma. Individuals with AB blood group have both antigen A and B on their RBCs, and no antibodies for either of the antigen in their plasma. Type O individuals are without A and B antigens on their RBCs, but have antibodies for both these antigens in their plasma. Individuals with blood group AB can receive blood of A, B or O group, while those with blood group O can donate blood to anyone.
7. (a)
A special neural centre in medulla oblongata can moderate the cardiac function through autonomic nervous system (ANS). Neural signals through the sympathetic nerves (part of ANS) can increase the rate of heart beat, the strength of ventricular contraction and thereby the cardiac output. Parasympathetic neural signals (component of ANS) decrease the rate of heart beat, speed of conduction of action potential and thereby the cardiac output.
8. (a)
In the given figure A is pulmonary vein which brings pure blood from lungs to left atrium, B is dorsal aorta which carries blood from heart to body parts, C is vena cava which carries impure blood from body parts to right auricle, and D is pulmonary artery which takes impure blood from heart to lungs.
9. (c)
In the given diagram the P-wave represents the electrical excitation (or depolarisation) of the atria, which leads to the contraction of both the atria. The QRS complex represents the depolarisation of the ventricles, which initiates the ventricular contraction. The contraction starts shortly after Q and marks the beginning of the systole. The T-wave represents the return of the ventricles from excited to normal state (repolarisation). The end of the T-wave marks the end of systole.
10. (c)
A- Artery Carries blood from heart to different body parts. It is thick-walled and elastic. The flow of blood in it is intermittent.
B – Capillary Nutrients, hormones, gases etc. can diffuse into tissue cells through capillaries and vice versa. It is thin-walled, and only one layer thick resting on basement membrane.
C – Vein Brings blood from different body parts to the heart. It is thin-walled and acts as low-resistance conduct for blood flow.
D – Pulmonary vein Two pulmonary veins from each lung transport the oxygenated blood to the left atrium.
11. (a)
Basophils have nucleus which is three-lobed and have less number of coarse granules. Their granules take basic stain and release heparin, histamine and serotonin. Lymphocytes form about 20% ofblood cells. They produce antibodies and are thus involved in immune response. Neutrophils are quite large and have many-lobed nucleus and abundant granules. Neutrophils are phagocytic in nature and are the most numerous of all leucocytes. Monocytes are the largest of all types of leucocytes and somewhat amoeboid in shape. They are motile and phagocytic in nature and engulf bacteria and cellular debris. Their life span is of 10-20 hours.
12. (c)
The blood group was O. The person having O blood group is universal donor. It lacks both antigens ‘A’ and ‘B’ thus does not cause agglutination or clumping of blood cells when transfused into person with any of the four blood groups.
13. (c)
Spleen is a vertebrate organ, lying behind the stomach, that is basically a collection of lymphoid tissue. Its functions include producing lymphocytes and destroying foreign particles. It acts as a reservoir for RBCs and can regulate the number in circulation. It is also the site for the breakdown of worn out RBCs and thus is known as graveyard ofRBCs. The life of an RBC is about 120 days. Liver cells degrade the haemoglobin of worn out RBCs into bile pigments (bilirubin and biliverdin).
14. (b)
‘Bundle of His’ is a part of heart. A bundle of nodal fibres, atrioventricular bundle (AV bundle), continues from the atrioventricular node (AVN) and passes through the atrioventricular septa. It emerges on the top of the interventricular septum and immediately divides into a right and left bundle, which give rise to minute fibres throughout the ventricular musculature of the respective sides called Purkinje fibres. These fibres along with right and left bundles are known as Bundle of His.
15. (d)
Blood plasma is a faint yellow, slightly alkaline and somewhat viscous fluid. The plasma contains a number of proteins serum albumin, serum globulins, properdin, prothrombin and fibrinogen. Prothrombin and fibrinogen play a role in blood clotting.
16. (b)
Arteries and veins are main blood vessels. Arteries carry blood from the heart to different body parts. Veins bring blood from different body parts to the heart.
17. (d)
If repeated checks of blood pressure of an individual is 140/90 or higher, it shows hypertension or high blood pressure. It leads to heart diseases and also affects vital organs like brain and kidney.
18. (c)
Refer answer 12.
19. (a)
By counting the number of QRS complexes that occur in a given time period, one can determine the heart beat rate (pulse) of an individual. The QRS complex represents the depolarisation of the ventricles, which initiates the ventricular contraction.
20. (d)
Tricuspid valve is the valve in the heart between the right atrium and right ventricle. It consists of three cusps that channel the flow of blood from the atrium to the ventricle. When the right ventricle contracts, forcing blood into the pulmonary artery, the tricuspid valve closes the aperture to the atrium, thereby preventing any backflow of blood. The valve reopens to allow blood to flow from the atrium into the ventricle. Thus, if tricuspid valve is partially non-functional the flow ofblood into the pulmonary artery will be reduced.
21. (a)
The body undergoes numerous changes at higher elevation in order to increase oxygen delivery to cells and improve efficiency of oxygen use. The early changes includes increased breathing rate, increased heart rate and fluid shifts. The later changes includes increased red blood cell production, increased 2, 3 DPG production and increased number of capillaries. Breathing rate and depth increase in response to lower concentrations of oxygen in the blood, causing more carbon dioxide to be-lost and more oxygen to be delivered to the alveoli. As acclimatization continues, the bone marrow contributes by increasing red blood cell production. New red blood cells become available in the blood within four to five days, increasing the blood’s oxygen-carrying capacity.
22. (c)
Intravenous injection is given for rapid distribution of drugs/substance. Intra-muscular injection is given for producing local effect.
23. (a)
The term angina means chest pain. In this disease enough oxygen does not reach the heart muscles. The patient experiences heart pain usually in front of the chest. AB blood group person have both antigens A and B, but do not have antibodies in the plasma. Due to the presence of both the antigens, AB blood group person can not donate blood to anyone. However, the person can receive blood from any blood group as it has no antibodies. Thus, AB blood group is a universal ; recepient.
24. (d)
25. (a)
Erythropoiesis is the formation of red blood cells (erythrocytes), which occurs in the red bone marrow. The earliest precursor that can be distinguished microscopically is the proerythroblast, which develops from a haemopoietic stem cell and gives rise successively to the early erythroblast, intermediate erythroblast, and the late erythroblast, in which most haemoglobin is synthesized. In mammals the nucleus is then forced out of the cell, which assumes a biconcave shape and is known as a reticulocyte. Reticulocytes are released into the blood and develops into mature erythrocytes.
26. (c)
A normal electrocardiogram (ECG) is composed of a P wave, a QRS wave and a T wave. The P wave is a small upward wave that indicates the depolarisation of the atria. This is caused by the activation of SA node.
27. (d)
Globulins in human blood plasma are primarily involved in defence mechanisms of body. Globulins like immunoglobulins act as antibodies that destroy bacteria, viruses and toxic substances that may enter into the blood from outside.
28. (b)
Lymph is a mobile connective tissue comprising j lymph plasma and lymph corpuscles (type of WBCs). Its composition is just like plasma except that it lacks RBCs and large plasma proteins.
29. (b)
Due to the pressure difference between the post caval and atrium, the blood passes from the post caval to the diastolic right atrium. Diastolic right atrium has less pressure and post caval has high pressure, thus blood moves from post caval to right atrium.
30. (b)
Phagocytes are cells that are able to engulf and breakdown foreign particles, cell debris and disease producing microorganisms. Neutrophils and monocytes (type of white blood cells) are the most active phagocytic cells.
31. (d)
Basophils are a type of white blood cell (leucocyte) that has a lobed nucleus surrounded by granular cytoplasm. They move about in an amoeboid fashion, are capable of ingesting foreign particles and they produce histamine and heparin as part of the body’s defences at the site of infection or injury.
32. (a)
Blood serum is blood plasma from which the fibrin and clotting factors have been removed by centrifugation or vigorous stirring, so that it cannot clot. Serum containing a specific antibody or antitoxin may be used in the treatment or prevention of certain infections. Such serum is generally derived from a nonhuman mammal (e.g. a horse).
33. (c)
Periplaneta has open circulatory system i.e. the blood does not flow in blood vessels but flows in a haemocoel (body cavity). The circulat ory systems of all vertebrates, as well as of annelids (for example, earthworms) and cephalopods (squid and octopus) are closed, in which the blood never leaves the system ofblood vessels consisting of arteries, capillaries and veins.
34. (c)
Clotting of collected blood can be prevented by-
• coating test tubes with silicon (which produce non wettable surface similar in its smoothness to endothelial lining ofblood vessels).
• adding chelating agents (includes trisodium citrate, sodium oxalate and sodium EDTA) which remove calcium which is important for blood coagulation, and prevent blood clotting.
• adding heparin, most powerful anticoagulant which acts indirectly by activating plasma antithrombin III. Heparin is effective both in vivo and in vitro. Whereas the option a, b and d are effective in vitro.
Heparinized blood is not suitable for blood counts (as it alters the shape of’RBCs and WBCs which affects blood testing), Fragility testing and complement fixation tests. Hence (c) is the correct answer.
35. (c)
SA node is a specialised bundle of neurons located in the upper part of the right atrium of the heart. SA node is the natural cardiac pacemaker from which the heart beat originates. If this system is damaged, it may send non-coordinated impulses to the heart chambers resulting in symptoms like irregular heart rate, tiredness, dizziness and loss of consciousness. As the pacemaker cells create these rhythmical impulse therefore an artificial pacemaker is implanted at the site of SA node to mimic the actions of the node and conducting system and helps to regulate heart beat.
36. (b)
Bundle of His is a network of cardiac muscle fibres found only in the ventricle wall. The bundle of His in continuation of the AV node gives off a left bundle branch at the top of the interventricular septum and continues as the right bundle branch. It is a part of conducting system along with other parts like SA node, intemodal atrial pathways, atrioventricular node, Purkinje system.
37. (c)
Human blood groups are special characteristics of blood in human and related primates due to presence of genetically controlled antigens and antibodies. ABO blood groups were the first to be discovered and are the most important in assuring sak blood transfusion. This system reflect the presence or absence of A and B agglutinogens (antigen) which are carried on the surface of plasma membrane of red blood cells. The ABO blood groups are determined by the gene I having three alleles — IA,IB,IO In human being, there are present two antigens A and B produced by IA and IB alleles respectively. These antigens are always present on the surface of RBCs. Also are present two antibodies in the plasma-anti A and anti B. Blood group AB has both antigens A and B but no antibodies.
38. (a)
Refer answer 35.
39. (b)
Lymph (called tissue fluid in the intercellular spaces) is a vascular tissue consisting of two parts-a clear, colourless fluid matrix, the plasma and floating amoeboid
cells, thc white blood cells, mostly lymphocytes. It differs from the blood in lacking red blood cells and some blood proteins. The lymph eventually enters the bloods near the heart.
40. (a)
Refer answer 37.
41. (c)
An artery has thick and more elastic wall but its lumen is narrow as compared to vein. Pulmonary artery carries deoxygenated blood from the right ventricle to the lungs for oxygenation. Pulmonary vein carries oxygenated blood from the lungs to the left auricle.
42. (b)
43. (d)
WBCs are the colourless nucleated amoeboid cells that can squeeze through blood capillaries by a process known as diapedsis. The increase in their number causes leukaemia, a cancer. WBCs are of two types, granulocytes (formed in bone marrow) and agranulocytes (formed in bone marrow and thymus).
44. (d)
Refer answer 35.
45. (d)
Blood consists of a watery fluid called plasma. Plasma is a faint yellow, slightly alkaline, viscous fluid. It consists of 90% water, 1% inorganic salts, 7% or 8% proteins and 1% of other substances. The inorganic salts in plasma occur as ions. Sodium is the main cation of plasma and chloride, the main anion. Potassium, calcium and magnesium occur in small arrtount.
46. (a)
Refer answer 37.
47. (a)
Arteriosclerosis is the hardening of arteries and arterioles due to thickening of the fibrous tissue, and the consequent loss of elasticity. In this disease, calcium salts precipitate with the cholesterol. This calcification ultimately makes the wall of arteries stiff and rigid. Arthritis is the inflammation of one or more joints, characterised by swelling, warmth, redness of the overlying skin, pain and restriction of motion. Aneurysm is a balloon like swelling in the wall of an artery due to degenerative disease or infection.
48. (a)
The temporary rise in blood pressure during the contraction of the heart is called systolic pressure and the temporary fall in blood pressure during relaxation of the heart is called diastolic pressure. Blood pressure is expressed as the ratio of the systolic pressure over the diastolic pressure. For a healthy resting adult person, the average systolic/diastolic pressures are 120/ 80 mm Hg.
49. (a)
Formation of WBCs, antibodies and destruction of bacteria occur in lymph glands while formation of RBCs occur in bone marrow. Lymph gland is a rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph glands filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. They are also called a lymph node.
50. (c)
Agranulocytes are leucocytes that lack granules in the cytoplasm. They are formed in spleen and lymph nodes and bone marrow. Since lymphocyte does not have granules in their cytoplasm so it is called agranulocyte. Lymphocytes are important in the body’s defence and are responsible for immune reactions as the presence of antigens stimulates them to produce antibodies. Another type of agranulocyte is monocyte. The other three are granulocytes which are produced in red bone marrow.
51. (c)
WBCs (also called leucocytes) are rounded or irregular colourless cells with a nucleus. They can change their shape and are capable of amoeboid movement. Leucocytes, formed in lymph nodes and red bone marrow, can produce antibodies and move through the walls of vessels to migrate to the sites of injuries, where they surround and isolate dead tissue, foreign bodies and bacteria. They survive for a few days generally 3-4 days after which they die and get phagocytized in blood, liver and lymph nodes.
52. (b)
Refer answer 35.
53. (a)
Lymph (also called tissue fluid in the intercellular spaces) is the colourless liquid found within the lymphatic system. An important function of lymph is to return interstitial fluid back to the blood. The interstitial fluid is the filtered form of the blood without the cellular components and plasma proteins. It consists of water containing dissolved materials. It receives C02, nitrogenous waste products, hormones and other synthetic substances from the tissue cells and enters the lymph capillaries to discharge them into blood.
54. (c)
Veins carry blood at low pressure as compared to blood carried by arteries. Arteries carry blood from the heart whose function is to pump blood at high pressure so that blood can reach each and every part of the body. Veins carry blood from tissues to the heart, so they carry blood at low pressure. Valves are present in the veins to prevent backflow of flood due to force of gravity.
55. (b)
The neurogenic heart is a characteristic feature of most arthropods and some annelids. In this, the heart beat is initiated by a nerve impulse coming from a nerve ganglion situated near the heart. The myogenic heart is a characteristic feature ofmolluscs and vertebrates. In this, heart beat is initiated by a patch of modified heart muscle itself. So, humans, rabbits and rats have myogenic heart.
56. (b)
The ‘dup’ sound is produced by the closure of the semilunar valves at the start of ventricular relaxation. It lasts for 0.1 seconds and its principle frequency is 50 cycles/sec. It is higher pitched, louder, sharper and of short duration as compared to Tub ’. The semilunar valves close to prevent any backflow of blood from aorta to the ventricles.
57. (b)
AV (atrioventricular) node is a mass ofmodified heart muscle situated in the lower middle part of the right atrium. It receives the impulse to contract from the SA node via the atria and transmits it through the atrioventricular bundles to the ventricles. AV node is called the pace setter. Here, the impulses are delayed for 0.1 second to ensure that the auricles will contract first and empty fully before the ventricles contract.
58. (d)
The wall of capillaries is very thin (usually less than one micron) and have numerous minute pores and made up of only endothelium. Exchange of material takes place between blood and tissue fluid across the endothelial membrane of capillaries through active diffusion. The wall of blood vessels (arteries and veins) is made up of mainly 3 layers – the outer most tunica externa has connective tissue, collagen fibres, lymph vessels and the middle tunica media has circular smooth muscle fibres some elastic fibres and the inner most tunica interna in a single layered endothelium of polyhedral squamous cells. If the arteries reach organs they form arterioles which are thinner and mainly consist smooth muscles and when they subdivide in the tissues they make capillaries..
59. (b)
In the embryo and foetal stage of vertebrates, RBCs and leucocytes are formed in the bone marrow, lymph nodes, yolk sac, liver, spleen and thymus but after birth they are formed in red bone marrow only.
60. (d)
61. (d)
Lymphocytes have a very large, rounded nucleus and scanty cytoplasm. They are nonmotile and nonphagocytic. They secrete antibodies to destory microbes and their toxins, reject grafts and kill tumour cells. They also help in healing of injuries. Thrombocytes aid in clotting of blood. Monocytes are phagocytic in nature. RBCs transport gases in the body.
62. (b)
Refer answer 37.
63. (c)
During transport of CO2 in the blood, about 70% of CO2 released by respiring tissue cells is transported as bicarbonate ions. It diffuses into the plasma and then into the RBCs. Here, CO2 combines with water to form carbonic acid. This reaction is catalyzed by a zinc containing enzyme carbonic anhydrase. Carbonic acid dissociates into bicarbonate and hydrogen ions. A small amount of bicarbonate ions is transported in the RBCs, whereas most of them diffuse into the plasma to be carried by it.
64. (c)
Refer answer 58.
65. (b)
The splenic artery is the blood vessel that supplies oxygenated blood to the spleen. It branches from the coeliac artery, and follows a course superior to the pancreas. The coeliac artery is the first major branch of the abdominal aorta and branches from the aorta around the level of the T12 vertebra in humans. It is one of three anterior/ midline branches of the abdominal aorta.
66. (d)
Wall of a vein consists of tunic externa, tunic media and tunica interna. All these layers are also present in the wall of artery. However, in the wall of a vein, the elastic membrane of tunica interna is relatively thin, and muscle fibres and elastic fibres in tunica media are fewer. Therefore, a vein has a thinner and less elastic wall but a wider cavity than an artery of the same diameter.
67. (a)
Pulmonary artery carries the blood from the right ventricle of the heart to the lungs for oxygenation so it carries deoxygenated blood.
68. (b)
Thromboplastin, a lipoprotein, helps in clot formation. Thromboplastin helps in the formation of an enzyme prothrombinase. This enzyme inactivates heparin and it also converts the inactive plasma protein prothrombin into its active form, thrombin. Both the changes require calcium ions. Thrombin converts fibrinogen molecule to insoluble fibrin. The fibrin monomers polymerize to form long, sticky fibres. The fibrin threads form a fine network over the wound and trap blood corpuscles (RBCs, WBCs, platelets) to form a crust, the clot. Thus, if calcium is removed from the blood, clotting process will not occur.
69. (c)
70. (b)
The right auricle opens into the right ventricle through a wide passage, the right auriculoventricular or A-V aperture. This aperture is guarded by a one-way valve called the tricuspid valve. The valve consists of three membranous flaps which are attached to the margin of the right auriculoventricular aperture above but project freely into the ventricle below. Their free lower edges are fixed to the papillary muscles of the right ventricle by a number of tough, white cords, the chordae tendineae.
71. (a)
Refer answer 39.
72. (c)
Presence of RBCs in the blood is known as hematuria. Alkaptonuria is the excretion of large amount of alkapton in urine which when comes in contact with light turns black. Proteinuria is the presence of proteins in the blood.
73. (b)
Rh factor plays a crucial role in child’s birth bom out of a marriage between Rh woman and a Rh* man. In such a case, the mother becomes sensitive while carrying a first Rh* child within her womb. The reason for such sensitivity is that some of the RBCs from the developing embryo get into the blood stream of the mother during development, causing her to produce anti-Rh antibodies. In fact, the first child of such parents is nearly normal and is delivered safely. However, if such a mother gets pregnant again, the subsequent Rh+ foetuses will be exposed to the anti-Rh antibodies produced by the mother. As a result serious damage to the red blood cells of the developing embryo will occur causing haemolytic disease of the newborn (HDN) or erythroblastosis foetalis. This disease leads to the death of the developing embryo before birth or after parturition.
74. (a, b)
The haemoglobin is broken down into haem i.e. iron and globin protein which is then converted into yellowish substance bilirubin which is extracted by the liver cells from the blood and stored in the form of bile in gall bladder.
75. (d)
RBCs do not occur in the blood of cockroach. The circulatory system of cockroach is of open type. Viscera lie in the haemocoel immersed in blood called haemolymph. The latter consists of colourless plasma and irregular white corpuscles, the leucocytes. There are no blood vessels except aorta that carries blood from the heart to the haemocoel.
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