Answer:
Five
Explanation:
There are five blood vessels that are attached to the heart.
Answer:
G
Explanation:because on the graphs is shows a huge drop of fossil tracks in the late Jurassic years
Bacteria that develop a mutation: artificial
Over a period of several thousand years: natural
Organisms that best adapt to their environment: natural
Alaskan sled dogs: artificial
Farmers only allow: artificial
The answer is directional selection
It is the mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction. The advantageous allele increases in frequency independently of its dominance relative to other alleles; that is even if the advantageous allele is recessive, it will eventually become fixed, changes the average value of a trait. Occurs most often under environmental changes and when populations migrate to new areas with different environmental pressures.
