A peptide built from three amino acids must have

• three side chains
• three carboxylate groups
• three amino groups
• three peptide bonds

A protein built from 12 identical polypeptide chains

• is encoded by a single gene
• can mutate 12 times faster than a protein with one chain
• can carry out 12 discrete functions
• must be an extracellular protein

In order for two polynucleotide strands to anneal

• the strands must be complementary
• paired bases must separate
• the temperature must be high
• new phosphodiester bonds must form

Could you explain which are correct and why?