Answer:
A to protect them from the sun but still allow air to flow near their skin.
Explanation:
I think
There is 10 kcal energy left in the 3rd trophic level.
All living organisms are made of only 20 different aminoacids- this is the correct answer! This means that the genetic code only codes for those 20 aminoacids (for example Glutamine and Lysine).
The 20 aminoacids that can form proteins are also called Proteinogenic amino acids.
Answer: a. action potential frequency is high enough that no relaxation of muscle fibers occurs.
Explanation:
A tetanic contraction occurs due to repeated stimuli at short intervals. In this situation, the muscle fiber does nor relax and contracts again. It is a process of sustained contraction of muscles, which evoke when the motor nerve innervates a skeletal muscle and emits the action potential at high rate. The muscles become hyperactive in this condition.
