Brown insects living in a dark background survived in a ratio of 90/120, while the same insects in a lighter background survived in a ratio of 30/120. The ratio of relative fitness of the insects in dark backgrounds to lighter backgrounds is given as

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