Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot.
The nucleus of the cell directs cell activity and acts like the control center. This is the place where gene activity is controlled in terms of the replication of the genes. In addition the movement and actions of the cell are also dictated from the nucleus.
Answer:
producers
Explanation:
All the energy comes from the sun. a small amount of sunlight energy is trapped by green plants and used in photosynthesis to form organic materials in plants that are sources of food to the rest of the animals. Animals get this energy when they feed on plants directly like the herbivores or indirectly like the carnivores.
Answer:
interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a 15.5–16 kDa protein[5] that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells
Explanation:
