How many nitrogen bases make up a codon?

Nucleic acid certain protein cell membranes certain carbohydrates

Set comes up with for examples of sound waves ocean wave light wave and hand wave which of tonys examples is not an actual scientific wave

The current thought on the structure of the cell membrane is: a. a static phosphate sandwich of lipids b. a fluid-mosaic of phospholipids and proteins c. a bilayer of proteins with static lipid molecules d. an impermeable bilayer of protein molecules e. a static and permeable phospholipid single layer