SA node is called the pacemaker because it initiates the cardiac impulse. AV node receives the impulse from the SA node and transmits it to the ventricles

Correct Option: A

SA node is called the pacemaker because it initiates the cardiac impulse. AV node receives the impulse from the SA node and transmits it to the ventricles

Periplaneta (P. americana, the Indian Cockroach) is an insect & insects do not have closed blood circulation. Their blood (called haemolymph) even does not serve for respiration. They do not possess blood vessels in this circulatory system and hence it is an open system.

Correct Option: A

Periplaneta (P. americana, the Indian Cockroach) is an insect & insects do not have closed blood circulation. Their blood (called haemolymph) even does not serve for respiration. They do not possess blood vessels in this circulatory system and hence it is an open system.

In a standard ECG, the P-wave is a small upward wave that indicates the depolarisation of the atria. This is caused by the activation of SA node.

Correct Option: C

In a standard ECG, the P-wave is a small upward wave that indicates the depolarisation of the atria. This is caused by the activation of SA node.

Leukaemia is a type of blood cancer, which is characterized by an uncontrolled increase in the number (through mitosis) of leucocytes in the blood.

Correct Option: A

Leukaemia is a type of blood cancer, which is characterized by an uncontrolled increase in the number (through mitosis) of leucocytes in the blood.

90/110 mmHg may harm vital organs like brain and kidney. This is called hypertension which can give rise to increased heart rate and palpitation.

Correct Option: D

90/110 mmHg may harm vital organs like brain and kidney. This is called hypertension which can give rise to increased heart rate and palpitation.