They are saying that every theory can eventually be changed a bit due to further research. It does not mean the theory is bad, just that it can become better.
<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
One way is that we have increased the amount of CO2 (carbon dioxide) in the atmosphere.
Could you please elaborate?
<span> Serratia marcescens primarily produces a bright red pigment called prodigiosin. Depending on the synthesis (partial or complete) of prodigiosin, the colour of the colony can be different. At the room temperature, prodigiosin production decrease which results in the white colour of Serratia. Serratia can also be colourless due to prolonged sunlight (UV mutagenesis).</span>
