Sean drew this diagram and labeled an unknown gas as gas a. which gas does a represent? oxygen hydrogen carbon dioxide nitrogen

Which part of a feedback mechanism is able to monitor the conditions outside of cells and usually uses nerve cells to relay this information to an intergrating center

The rules of engagement (roe) working group is often used to (select all that apply.)

What method(s) do plants use to obtain nitrogen? select all that apply. absorb it from the atmosphere use bacteria to convert nitrogen to usable form obtain usable nitrogen compounds from the soil absorb nitrogen from water taken in at the roots