Answer:
spiral staircase
its a double helix, which is what DNA is
D) This is a point mutation, resulting from the substitution of one nitrogen base. If this strand of DNA is used for transcription, it will affect the coding of ONE amino acid, resulting in placing the correct amino acid in the protein, placing the wrong amino acid in the protein, or coding for the protein to stop build.
Salinity is the number one factor for determining what living things can survive in a body of water
the answer is C or the third one down, Layer A is the outer core because its made of iron and nickel