What are the two basic requirements for gas exchange. I know they are ventilation and perfusion, but are they any simpler words?

Which level of consumer had access to the smallest apply of energy

Which ideas did your answer contain? check all that apply. no food for organisms no oxygen in the atmosphere no trees or flowering plants no products based on trees or plants (building materials, medicines, fuels, fibers) no fossil fuels

2. sketch the inside of the bean nodule, and describe or label what you observed with the hand lens.