D.
A fixed allele is homozygous within a population so D should be the correct answer.
Hope this helps!
Cell specialization allows cells to perform essential cell specific tasks. Such as nerve cells, red blood cells etc.
Answer:
my guess would be neither because its just saying "cancerous" not which type but im not sure..
Explanation:
Where are the statements, huh wait what
Primary succession starts with bare rock which is broken down by either lichen or moss to make soil while secondary succession starts with developed soil