Actively transport molecules across the cell membrane
Answer: salt
Freshwater is defined as having a low salt concentration, usually less than 1%.
Explanation:
Freshwater refers to the bodies of water that contain very low levels of dissolved salts. So, freshwater are unique for their low salt content (about 0.5% of salt) compared to the sea water with high salt content.
Examples of freshwater include rivers and spring
Answer
The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it.
Explanation:
Production of T-helper I cytokines like IFN gamma, IL-2 and IL-18 is highly protective against helminth infection by activating the macrophage intracellular killers. Protection against mucosal eosinophil responses in which antiparasitic chemicals are released. Killing also involves direct cytotoxic mechanisms in which T- cell and NK-cells directly release antiparasitic agents like perforin and granulysin which kill the parasite.
D. Low side pressure is high and high side pressure is low