Body Fluids and Circulation — Page 5 | NEET Biology

Q41

Closed circulatory system occurs in vertebrates and some invertebrates such as

A cockroach

B tadpole/fish

C mosquito

D housefly

Correct Answer

Option B

Solution

(b) Closed circulatory system where blood flows in definite vessels - includes vertebrates like fish.

Q42

'Dup' sound is produced during closure of

A Semilunar valves

B Bicuspid valve

C Tricuspid valve

D Both b and c

Correct Answer

Option A

Solution

(a) Second heart sound Dup is produced by closure of semilunar valves.

Q43

The correct route through which pulse-making impulse travels in the heart is

A AV node bundle of His SA node Purkinje fibres heart muscles

B AV node SA node Purkinje fibres bundle of His heart muscles

C SA node Purkinje fibre bundle of His AV node heart muscles

D SA node AV node bundle of His Purkinje fibre heart muscles

Correct Answer

Option D

Solution

(d) The pulse making impulse travels: SA node AV node bundle of His Purkinje fibres heart muscles.

Q44

An adult human with average health has systolic and diastolic pressures as

A 70 mm Hg and 120 mm Hg

B 120 mm Hg and 80 mm Hg

C 50 mm Hg and 80 mm Hg

D 80 mm Hg and 80 mm Hg

Correct Answer

Option B

Solution

(b) Normal adult blood pressure is 120 mm Hg systolic and 80 mm Hg diastolic.

Q45

Contraction of the ventricle in the heart begins by the command from

A Chordae tendinae

B S.A. node

C Purkinje fibres

D A. V. node

Correct Answer

Option B

Solution

(b) SA node generates the rhythmic cardiac impulse.

AV node receives impulse from SA node and transmits it to ventricles.

Q46

The active molecule that helps initiate the inflammatory response when mast cells degranulate is

A perforin

B histamine

C heparin

D insulin

Correct Answer

Option B

Solution

(b) Mast cells contain granules of heparin and histamine. Histamine produces inflammation.

Q47

Pulmonary artery differs from pulmonary vein in having

A no endothelium

B valves

C large lumen

D thick muscular walls

Correct Answer

Option D

Solution

(d) Arteries have thick wall and narrow lumen while veins have thin walls and large lumen.

Q48

Impulse of heart beat originates from

A S. A. node

B A. V. node

C Vagus nerve

D Cardiac nerve

Correct Answer

Option A

Solution

(a) SAnode is called the pacemaker because it initiates the cardiac impulse.

Q49

Which of the following is not a granulocyte?

A Lymphocyte

B Eosinophil

C Basophil

D Neutrophil

Correct Answer

Option A

Solution

(a) Granulocytes: neutrophils, basophils, eosinophils. Agranulocytes: lymphocytes and monocytes.

Q50

With respect to the ABO group, there are four major blood types because this blood group is determined by

A three alleles, all of which are recessive.

B three alleles, of which, two are recessive and the third is dominant.

C three alleles, of which two are co-dominant and the third is recessive.

D three alleles, all of which are co-dominant.

Correct Answer

Option C

Solution

(c) Blood group is determined by three alleles - IA, IB, and IO. Alleles IA and IB are codominant.