How many chromatids does a chromosome have before dna replication?

Brainlest awardhow does smoking and arterial plaques increase the risk of hypertension? (2 points) select one: a. both increase blood volume. b. both decrease blood volume.c. both expand the diameter of the blood vessels. d. both constrict the diameter of the blood vessels.

What two atoms form a covalent bond a.a sodium and chlorine atom b. an iron and oxygen atom c. two oxygen atoms d. two sodium atoms apex

Who is volunterring to with a lot of easy science questions? will give brainliest. i need and i need it now