It’s is B i took the test
D: All the variables are controlled except one.
Answer:
Genes & DNA
Explanation:
Heritable traits are known to be passed from one generation to the next via DNA, a molecule that encodes genetic information.Organisms inherit genetic material from their parents in the form of homologous chromosomes, containing a unique combination of DNA sequences that code for genes.
I don't know the real answer because you didn't attach the choices, but Adenine (A) is always paired with Thymine(T) and Guanine (G) is always paired with Cytosine (C).