Explanation:
In many cases, behaviors have both an innate component and a learned component. Behavior is shaped by natural selection. Many behaviors directly increase an organism's fitness, that is, they help it survive and reproduce.
Red and dry skin. (I'm a Nursing major)
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.
Microvilli which line down the luminal surface of those epithelial cells represent the resorptive function of the proximal tubule.
<span>The high quantity of mitochondria inside the epithelial cells of the proximal convoluted tubule is needed in order to supply the energy for the active transport of sodium ions (to enter the cell from the luminal side).</span>
