Why do genes in eukaryotic cells have intronss?

What was photo 51 with rosalind franklin?

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

What changes the stability of the element