The answer is number 4 hope this helps
The secondary structure is responsible for the shape that the nucleic acid assumes. The bases in the DNA are classified as purines and pyrimidines. ... A purine base always pairs with a pyrimidine base (guanine (G) pairs with cytosine (C) and adenine (A) pairs with thymine (T) or uracil (U)).
Active transport could transport material across the membrane against the concentration gradient
Answer:
ANSWER E. a and c are the answer to this question