Enzymes that synthesize dna or rna can synthesize in a direction.

The answer is 5'-3'.

Enzymes that synthesise DNA are called DNA polymerases. They move along DNA strand in 3'-5' direction so that newly synthesised DNA strand is in 5'-3' direction.
Enzymes that synthesise RNA are called RNA polymerases. They move along a template DNA strand in 3'-5' direction so that newly synthesised RNA is in 5'-3' direction.

The two spiders in United States that are poisonous: Black widow (southern and western) prefer staying hidden in sheds, garages or piles of debris. The female's bite is most dangerous. The venom of these spiders is very potent.
Brown recluse (southern and mid western states) range in color from cream to very dark brown; have six eyes; are known to occasionally bite humans, injecting their poisonous venom into the blood stream.