What usually drives animal research is the benefit to human beings of that research?

Discuss the functions of epithelial connective nerviud and muscular tissues

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons