Answer:
D. A signal is sent down an exon within a nerve cell
Explanation:
organization, metabolism, responsiveness, movements, and reproduction.
The correct answer is A. Two populations of finches that cannot produce viable offspring
Explanation:
Reproductive isolation is a biological and evolutionary phenomenon that prevents two species from successfully reproducing, this means they cannot produce offspring or the offspring is not fertile, even if these species had a common ancestor. Additionally, as a result of reproductive isolation, each species keeps its genes and features. This phenomenon is best exemplified in "Two populations of finches that cannot produce viable offspring " because this refer to the barriers for different species to reproduce or produce viable offspring, which is the focus of reproductive isolation.
Human evolution known to be a process in which species adapt to certain
conditions of life, and in the battle of life and death, they are forced
to become stronger in order to survive in this world. Diseases have
always been present during the evolution, acting themselves as a natural
selectors - the weaker organisms get sick and die. Not just humans, but
all species have to establish a great protecting mechanism in order to
survive. That is how our bodies are built, to be able to withstand and
survive in the conditions we live in, and that is why our immune system
has to be taken care of.
