Hummingbirds can fly as fast as 60 miles per hour. One reason why its a scientific question is because of their speed. Their speed is very different compared to many other animals. I hope this helps :)
A sperm and an egg cell are each gametes. They fuse to become a zygote cell which develops into a fetus
Answer:
Answer is C.
Explanation:
A. The vessel length is pretty much constant. The body can't length or shorten blood vessels.
B. Blood viscosity is also fairly constant because the composition of blood cannot change quickly enough to change resistance as needed.
C. This is the main way resistance is controlled. The smooth muscle surrounding blood vessels can rapidly respond to hormonal or metabolic stimuli and contract/relax to adjust diameter.
D. Again, temperature is fairly constant in the body and would not be a good way to alter resistance.
Answer:
Explanation:
they can not chose to adapt. adaptations occur over a very long period time(darwinism) Evolution is not selective in the sense that the organism being changed can choose.