Agroup of organisms that changes over time is said to

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

The first amino acid of a new polypeptide chain is

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