The cholera bactery evolves which means it changes the way it works. So if you are vaccinated, the bactery will evolve itself in such a way that your body doesn't reject it.
Answer:
d.The wing-assisted incline running theory postulates that wings were initially used to maintain balance while climbing up slopes.
Explanation:
Two theories were given to explain the origin of avian flight. The top-down theory suggested that the birds' ancestors were tree dwelling species. They took help of wings to glide from tree to tree in order to avoid predator or catch prey. The bottom up theory suggested that the birds' ancestors were ground dwelling species. They took help of wings to maintain a balance and provide a lift for efficient running.
Wing-assisted incline running was a mixture of both the above theories and gave a balanced view point. According to it, birds' ancestors used wings to maintain a balance while running up inclined slopes. The wings helped them to save energy while scaling slopes and eventually a flight mechanism was also developed.
<span>Large changes in allele frequencies can occur in a short time - any changes in frequency, occurring as a result of random chance, would have a proportionally larger effect in a small population. </span>
Mass is the amount of matter in any object.
