<span>When the surface layer was dug up, the permafrost was exposed. When the weather warmed, this exposed permafrost would have melted and become soggy, causing the ground underneath the tracks to shift.</span>
Variables is likely the correct answer.
<span>3,3',5,5'-Tetramethylbenzidine or TMB is a chromogenic substrate visualising reagent used in enzyme-linked immunosorbent assays (ELISA), it yields a blue color when oxidized, typically as a result of oxygen radicals produced by the hydrolysis of hydrogen peroxide by HRP, (thermofisher). The expected colorimetric result from the negative control in your assay will be no development of blue color</span>
When alleles are recombined during sexual reproduction, they can produce dramatically different phenotypes. Thus, sexual reproduction is a major source of variation within many population. Asexual<span> production is when there is one parent that produces offspring that are identical to the parent. Basically a copy of the parents DNA.
Your answer in short is B
</span>
Is this school work ? can you tell me so i can tell you professical or common