<span>The primordial germ cell in the embryo undergoes mitosis to produce a spermatogonial stem cell.
The spermatogonial stem cell undergoes mitosis. The new cells could either be stem cells or spermatogonium cells.
The spermatogonium undergoes mitosis to generate a primary spermatocyte.
*** Up until this point, all cells are diploid ****
The primary spermatocyte (diploid) undergoes MEIOSIS I to generate TWO haploid secondary spermatocytes.
Each secondary spermatocyte undergoes MEIOSIS II to generate a total of FOUR early spermatid.
The spermatid mature in the seminiferous tubule, and once they are completely mature they are released into the lumen.
Now called sperm cells, they pass into the epididymis, where they are stored until time to be released during ejaculation
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Answer: About 16 months to 4 years.
Explanation: Depending on the specific nursing program you enroll in. On average, becoming a registered nurse can take 3 years.
There are many lines of evidence which clearly show that the atmospheric CO2<span>increase is caused by humans. The clearest of these is simple accounting - humans are emitting CO2 at a rate twice as fast as the atmospheric increase (natural sinks are absorbing the other half). There is no question whatsoever that the CO2 increase is human-caused. This is settled science.</span>
Peristalsis is the movement of particles through the digestive tract
Answer:
B) Viruses are killing some of his B cells and becoming incorporated into the genomes of others.
Explanation:
Epstein-Barr virus causes infectious mononucleosis by following mechanism.
1) Epstein-Barr virus attaches to and infects epithelium of the throat where it replicates and causes pharyngitis.
2) Virions enter the lymphoid vessels and are carried to the lymph nodes. Some virions escape the lymphnode trap and are carried to the bloodstream.
3) Virions attach specifically to B lymphocytes and infect them, producing either latent infection or productive infection.
4)The infected B lymphocytes actively replicate and differentiate into cells producing random immunoglobulins.
5)T cells respond to infection and destroy the lymphocytes replicating EBV vitus.
6) Latently infected B lymphocytes become immortal. They are not attacked by T cells.
