First heart sound is produced during closure of

• auriculo-ventricular valves

• eustachian valve

• sinus valve

• seminular valves

Christmas disease in another name for

• Down's syndrome

• sleeping sickness

• haemophilia-B

• hepatitis-B

'Bundle of His' is a network of

• nerve fibres distributed in ventricles

• nerve fibres found throughout the heart

• muscle fibres distributed throughout the heart walls

• muscle fibre, found only in the ventricle wall

Iron is stored in bone marrow as

• haemosedrin

• ferritin

• haematin

• None of these

Systemic heart refers to

• entire heart in lower vertebrates

• the two ventricles together in humans

• the heart that contracts under stimulation from nervous system

• left auricle and left ventricle in higher vertebrates

ABO blood grouping is controlled by gene I which has three alleles and show co-dominance. There are six genotypes. How many phenotypes in all are possible?

• Three

• Six

• Five

• Four

Which of the following genotypes does not produce a sugar polymer on the surface of the RBCs?

• I^AI^A

• I^Ai

• ii

• I^AI^B

A person was found to possess reduced haemoglobin content in the blood, caused due to disturbance in formation of RBCs. He is suffering from

• Vitamin-B₁ defeciency

• Vitamin-A defeciency

• Vitamin-B₁₂ defeciency

• Vitamin-E defeciency

Red muscle cells are rich in

• only myosin

• haemoglobin and glucose

• lactic acid and acetic acid

• myoglobin and cytochrome

Heart sound dub is caused due to closing of

• valve

• tricuspid valve

• semilunar valve

• None of the above