41-Steroids are a class of lipids. Which of the following is an example of a steroid found in the human body?
(d)Phenol
(a) Acetylcholine
(b) Cholesterol
(c) Carboxylic acid

Explanation:

As the name suggests, cholesterol is a sterol (a modified steroid). It is biosynthesized by animal cells.

characterization of nanoparticles is a critical step in nanomaterial production as it provides information of dimension, morphology, surface charge, distribution and degree of surface functionalization.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.