Help me out pleases

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

Select the correct answer. which mutation is harmful to the organism? a. a mutation allowing moths to camouflage better on blackened tree bark b. a mutation making staphylococcus aureus resistant to the antibiotic methicillin c. a mutation inhibiting human immunodeficiency virus from attaching to and entering the cell d. a mutation causing uncontrolled cell division e. a mutation giving plant leaves a bitter taste to discourage herbivores from eating them

Which of the following particles always has a positive charge? a. electronb. neutron c. proton d. ion