In DNA methylation, the most frequently methylated nitrogenous base is the cytosine. Its methylation is widespread in prokaryotes and eukaryotes. Its rate of DNA methylation differs greatly between different species like Arabidopsis thaliana which is 8%, Physarum, 4%, Mus musculus, 2.3%, and etc.
The slopes show that sucrose gradient affects change in weight.
The slopes will be different because higher gradient concentration of sucrose will result in the higher amount of water moved. This means the higher sucrose gradient concentration, the more change in weight of the water.
<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
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cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
As the ribosome reads each codon of mRNA, it directs tRNA to bring the specified amino acid into the ribosome. Each tRNA molecule carries<span> just one kind of amino acid. In addition, each tRNA molecule has </span>three unpaired bases<span>, </span>collectively called the anticodon<span>—which is complementary to one mRNA codon.</span>
