What is correct about leukocytes?
A) They are red coloured
B) They can cross capillaries
C) They are enucleate
D) Decrease in their number causes leukemia

Hint: Leukocytes are also called white corpuscles. It has a nucleus. It helps our body to defend against various deadly infections. You can also call it, the cellular component of blood.

Complete Answer:
- They don’t contain hemoglobin.
- They have nucleus
- They can move in our body through the walls of capillaries. So, they can cross capillaries.
- An increase in their number can cause leukemia.
- They can destroy infectious agents and cancerous cells in the human body.

So, the correct answer is they can cross capillaries.

The erythrocytes can only circulate within the bloodstream but leukocytes leave the bloodstream to perform the body defense system. The leukocytes have amoeboid movement due to which they can easily squeeze out of the capillaries and the whole process is called diapedesis.

Additional information:
Broadly, the leukocytes are divided into two main categories-
Granulocytes (contain granules) - neutrophils, eosinophils, basophils.
Agranulocytes (no granules) - lymphocytes and monocytes.

Note: White blood cells perform a very crucial role in the human immune system. It protects our body from infectious disease and fatal disease agents.