The Answer is B................
Answer:
the hormone receptor is a heterotetramer composed of two subunits with 95 kDa and two subunits with 135 kDa
Explanation:
In this case, the heterotetramer is composed of two heterodimers, each composed of two subunits that held together by disulfide bonds. These heterodimers bind together through hydrophobic interactions in order to form a tetramer. The Sodium Dodecyl Sulfate (SDS) is a denaturing detergent that dissociates both heterodimers by interfering with hydrophobic interactions that hold heterodimers together. It is for that reason that only a single band of 230 kDa is observed (135 kDa + 95 kDa = 230 kDa). Moreover, 2-Mercaptoethanol breaks disulfide bonds, thereby separating the two subunits in the heterodimer. In consequence, after the use of this chemical compound (2-Mercaptoethanol), two different bands with 135 kDa and 95 kDa can be observed.
Answer:
Allopatric speciation
Explanation:
Allopatric speciation is a type of speciation that takes place when a group of species are divided into two different groups which are separated from each another. In allopatric speciation, a geographic barrier such as a water body (river) or a mountain range forms and prevents the species from mating with each other. As the species are separated into two groups, each of them develops its own distinct traits based on the demands of their unique environment or the inherited traits of the group that are passed on to offspring.
I think the answer is d because the bodys first line of defense is both physical and chemical barriers ect. skin, tears, mucus, cilia, stomach acid and urine flow
