The correct answer is Galen.
Galen considered anatomy as the foundation of medical knowledge, and he recurrently dichotomized and tested on the lower animals like pigs, sheep, and goats. Galen's supported dissection as the method to better the skills of surgery and research works.
In his work, he illustrated seven pairs of cranial nerves, observed the structural distinctions between the veins and arteries, and illustrated the valves of the heart.
As you go up in an ecosystem the bigger animals have less energy. While the organisms down at the bottom like plants that create their own energy have greater amounts. This is because energy is rated doing everyday things. As energy travels up the food pyramid, it looses more and more energy. This is knower as the 10% rule. In which every time you go up 10% of energy is lost.
C: lack of water during long periods..
Seasons are Winter, Spring, Summer And Fall. The Sun moving (orbiting earth) causes them. So in the winter, the sun is on the opposite side of the world, and that's why it is so cold. In the summer, the sun is facing straight at us. Other season's, the sun is kinda in between, if that is any help