A gateway substance is something that may be menial but could lead to something bigger, an example is weed in the drugs world, weed is not hard to get and is usually a gateway drug to stronger types of drugs and potentially more dangerous
Answer:
endemic species
Explanation:
Species found in only one place on earth are called endemic species
Answer:
Water
Explanation:
Molecular oxygen is the terminal electron acceptor and serves to receive electrons from reduced NADH and FADH2 to reoxidize them. NADH and FADH2 are formed during glycolysis and Kreb's cycle. These reducing powers should be re-oxidized to enter in the first two steps of aerobic respiration again.
For the purpose, NADH, and FADH2 transfer their electrons to the molecular oxygen via electron transport chain. After accepting the electrons, molecular oxygen is oxidized into the water molecule. Therefore, radioactive oxygen isotope would appear in the form of a water molecule after completion of cellular respiration.
Infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Infectious disease, also known as transmissible disease or communicable disease, is illness resulting from an infection.
Answer:
TCR
Explanation:
Helper T cells are the CD4T cells that are present in the inactive form. These cells have receptors for antigens on their surface. These antigen receptors are called T-cell receptors (TCRs). The function of TCR is to recognize and bind to specific foreign antigen fragments that are presented in antigen–MHC complexes. Different helper T cells have their unique TCRs to recognize a specific antigen–MHC complex. The CD4 proteins of helper T cells also interact with the MHC antigens and help maintain the TCR–MHC coupling.
