The shape of DNA is described as a double helix. Click all that apply to the description of DNA. a. DNA is made from a single strand of nitrogenous bases.
b. A double helix resembles a “twisted ladder”
c. The “backbone” of the ladder is made up of alternating sugar and phosphate groups
d. The “rungs” of the ladder are made up of the bases joined by hydrogen bonds

According to this food web which of the following would be considered primary consumers

In the ocean why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.