testosterone, a lipid-soluble signaling molecule, crosses the membranes of cells throughout the body but affects only target cells because:

Football players often sustain lateral blows to the extended knee. which of the ligaments is (are) damaged as a result? a. suprapatellar b. oblique popliteal and extracapsular ligament c. medial collateral, medial meniscus, and anterior cruciate d. arcuate popliteal and the posterior cruciate

Which of the following represents the correct format for the scientific name? a. staphylococcus aureusb. staphylococcus aureusc. staphylococcus aureusd. staphylococcus aureus

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?