Answer:
Macrophages are part of your innate immune system, which is antigen-independent and does not require activation.
Explanation:
Macrophages phagocytize (internalize) all non-self pathogens it encounters. These do their job without activation. Other cells in the innate immune system include basophils, neutrophils, eosinophils (these cells are polymorphonuclear leukocytes), mast cells, and dendritic cells, which act as the bridge between your innate and adaptive immune system.
All of the other entities listed above are part of your adaptive immune system. The adaptive immune system is antigen-dependent and requires activation. This section of your immune system responds differently to different pathogens, and has the bonus of having immunologic memory, the ability to remember pathogens after infection and respond much quicker upon secondary and tertiary encounters.
Note: All lymphocyte types begin as naïve cells, which then differentiate into their fully matured form upon activation.
Helper T cells are a type of CD4+ T cell that has the job of activating B and T lymphocytes. There are two different types of T helper cells: Th1 and Th2. Th1 cells secrete the cytokine interferon-gamma (IFNγ), and is primarily involved with the stimulation and activation of cytotoxic T cells, while Th2 cells secrete a variety of cytokines and are responsible for activating and assisting with B cells to make antibodies. To make a long story short, Th cells interact with APC (Antigen Presenting Cells), specifically their Class II MHC (a group of genes that present exogenous proteins). The Th cells then proliferate and gain the ability to activate these APC cells and provide the necessary signals to activate B and T cells and make them proliferate and do their specific function.
The earth's tilt. The tilt of the Earth on it's axis is what makes the sun heat up different parts of the Earth at different times, thus making wind, thus making different weather patterns. Depending on how much sun (heat) the area is getting, it changes the weather.
Explanation:
diffusion is movement of molecules from a region of higher concentration to a region of lower concentration
2a)molecules will be moving out of the cell
b)molecules will be moving into the cell
3i)molecules will be moving into the cell
ii)molecules will be moving out of the cell
iii)there is no movement since concentration is equal inside and outside the cell
The Gulf Stream<span>, together with its northern extension towards Europe, the </span>North Atlantic<span> Drift, ... Click here for more information. ... By carrying warm </span>water<span> northeast across the Atlantic, it </span>makes<span> Western and especially Northern ... The </span>North Atlantic Current<span> of </span>the Gulf Stream<span>, along with similar warm air currents, helps keep ...</span>
