1. Which is not a part of the respiratory system? Alveoli, Lungs, Trachea,
Esophagus

Chlorophyll is found in plant leaves and absorbs light from the sun to enable plants to perform photosynthesis. magnesium is an important component of chlorophyll. the concentration of magnesium ions is higher in the root-hair cells of plants than in the soil. which mechanism of ion uptake would best enable a plant to produce a steady supply of chlorophyll? osmosis diffusion passive transport active transport

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Stephen is a student who wants to test his knowledge of medical terminology. which option could he use?