The androgen-binding protein functions to
a. confer responsiveness of certain cells to male sex hormones.
b. transport androgens in the plasma.
c. bind and maintain high concentrations of testosterone in the seminiferous tubules.
d. a and b.
e. a, b and c

C. Bind and maintain high concentrations of testosterone in the seminiferous tubules.

Explanation:

Seminiferous tubules are present within the testis of male reproductive system. In adults, each testis is oval in shape and is about 4-5 cm in length. Each testis has about 250 compartments called testicular lobules. These compartments contain highly coiled tubules called seminiferous tubules.

Within the seminiferous tubules, the male gamete i.e sperms are produced. Seminiferous tubules are lined inside by two types of cells called male germ cells (spermatogonia) and sertoli cells.

Spermatogonia give rise to spermatozoa which are released into the lumen of the tubule. In between spermatogenic cells, sertoli cells or sustentacular cells or nurse cells are present which provide nourishment to developing spermatozoa.

One of the function of sertoli cells are to release androgen binding protein (ABP) which binds and concentrates testosterone with in the seminiferous tubules.

The hormone testosterone is produced by the interstitial cells of Leydig located around the seminiferous tubules.

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure

the answer is d.) homologous; have mammary glands