Answer:
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.
Some of the major factors which affect the genetic equilibrium and induce the variability in population are as follows: (A) Mutations (B) Re-combinations during Sexual Reproduction (C) Genetic Drift (D) Gene Migration (Gene Flow) (E) Natural Selection.<span />
Answer:
the end of G1 phase, end of G2 phase, and partway through M phase (the spindle checkpoint) to regulate the cell cycle.
Explanation:
The air that we breathe is mostly made up of nitrogen (78%). 21% is oxygen which is needed for animals and humans in respiration and 0.03% is carbon dioxide which is needed for plants to make energy in a process called photosynthesis. The bit that is left is made up of rare gases like helium and argon and methane.
<span>In the skeletal muscle cells of vertebrates, as many as 38 molecules of ATP are produced from one molecule of glucose. This is less than might be expected, because electrons from NADH produced during glycolysis must be shuttled through the inner mitochondrial membrane at a cost.
</span>The energy of the electrons can be used to make ATP and in eukaryotes, glycolysis occurs in the <span>cytosol, outside mitochondria. </span>