The exoskeleton of an arthropod is chitin.
B la patogenicidad de un virus
Biological structures like DNA, proteins and cells all depend on molecules. ... Neurotransmitters like epinephrine are pretty simple molecules, but without them our nervous system couldn't work. Oxygen, containing just two oxygen atoms, is a very simple molecule, and it is certainly essential to living things.
In Newton's Third Law of Motion, when one object exerts a force on a second object, the forces are equal in magnitude and opposite in direction. The correct answer is B.
