Hypokalaemia means

Match the following:
Types of leucocytes | Function
$A.$ Neutrophils | $1.$ Heparin and histamine secretion
$B.$ Basophils | $2.$ Antibodies formation
$C.$ Acidophils | $3.$ Scavenger
$D.$ Monocytes | $4.$ Phagocytes
$E.$ Lymphocytes | $5.$ Antiallergic and healing of wounds
The correct pairing sequence is:

Assertion $A$: In an open circulatory system,the blood volume is high,but the blood pressure is low and irregular.
Reason $R$: In a closed circulatory system,the blood volume is limited,and the blood pressure is high and regular.
Which option is correct for Assertion $A$ and Reason $R$?

Cardiac output is determined by which of the following?

Which organ in an adult human causes the least damage if removed?

Which of the following organs is known as the blood bank of the body?