Which one of the following animals has two separate circulatory pathways?

1. Frog

2. Lizard

3. Whale

4. Shark

Doctors use stethoscope to hear the sounds produced during each cardiac cycle. The second sound is heard when

1. AV valves open up

2. Ventricullar walls vibrate due to gushing in of blood from atria

3. Semi lunar valves close down after the blood flows into vessels from ventricles

4. AV node receives signal from SA node

Which one of the following is correct ?
1. Serum = Blood + Fibrinogen
2. Lymph = Plasma + RBC + WBC
3. Blood = Plasma + RBC + WBC + Platelets
4. Plasma = Blood – Lymphocytes

Person with blood group AB is considered as universal recipient because he has:

1. both A and B antigens on RBC but no antibodies in the plasma

2. both A and B antibodies in the plasma

3. no antigen on RBC and no antigens in the plasma

4. both A and B antigens in the plasma but no antibodies

How do parasympathetic neural signals affect the working of the heart?

1. reduce both heart rate and cardiac output

2. Heart rate is increased without affecting the cardiac output

3. Both heart rate and cardiac output increased

4. Heart rate decreases but cardiac output increases

The diagram given here is the standard ECG of a normal person, The P - wave represents the 

1. Initiation of the ventricular contraction

2. Beginning of the systole

3. End of systole

4. Contraction of both the atria

Figure shows schematic plan of blood circulation in humans with labels A to D. Identify the label and give its function/s. 

1. B-Pulmonary artery- takes blood from heart to lungs, PO₂ = 90mm Hg

2. C-Vena Cava- takes blood from body parts to right auricle, PCO₂ = 45mm Hg

3. D-Dorsal aorta- takes blood from heart to body parts, PO₂ = 95mm Hg

4. A- Pulmonary vein - takes impure blood from body parts, PO₂ = 60mm Hg

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?

1. Blood group B

2. Blood group AB

3. Blood group O

4. Blood group A

Which one of the following human organs is often called the "graveyard" of RBCs ? 

1.  Kidney 

2.  Spleen 

3.  Liver 

4. Gall bladder