# In the DNA molecule :

(1) there are two strands which run antiparallel one in 5' $\rightarrow$ 3' direction and other in 3' $\rightarrow$ 5'

(2) the total amount of purine nucleotides and pyrimidine nucleotides is not always equal

(3) there are two strands which run parallel in the  5' $\rightarrow$ 3' direction

(4) the proportion of Adenine in relation to thymine varies with the organism