What is the function of the human spleen?

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:

Analogy type questions:
$(1)$ Fish : Single circulation :: Amphibians : ...........
$(2)$ Between right atrium and right ventricle : Tricuspid valve :: Between left atrium and left ventricle : .............

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

Which one of the following is a correctly matching pair of a certain body feature and its value/count in a normal human adult?

The state of equilibrium in the body with respect to various functions and to the chemical composition of fluids and tissues is called