Mitochondrial DNA mutation occurs at a constant rate throughout history. Thus, each different base in Mitochondrial DNA is able to show just how long ago the 2 species diverged from each other.
Hope this helps! :)
Oxygen and carbon dioxide. ☺♥
Insects grow larger in populations after awhile after usin the insecticide
Answer:
A callus is a hardening of skin, keratin is the protein which is abundant in callus. Skin is a protective layer against a external environment. Outer layer of skin consist of keratin which is also found in hair. Callus is the accumulation of dead cells result due to friction and pressure exerts on the part in which they are present. The keratin component (keratinocytes) remains undifferentiated in these dead cells which causes hardening in callus.