I think the answer is liver and hepatic portal vein
Hope this helps
Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
Osmosis is the diffusion of water molecules only through a membrane
Answer:
Phototrophs
Explanation: Some organisms obtain their energy from the sun by the process of photosynthesis. These organisms are known as phototrophs because they can make their own organic molecules using sunlight as a source of energy.
