Answer:
b). activation of T cells
Explanation:
An APC (antigen-presenting cell) can be described as an immune cell, which detects, uptakes, and informs the acquired immune response when an infection takes place. B cells, macrophages, and dendritic cells are antigen-presenting cells.
These cells play an important role in activation of T cells. T cells are unable to recognize soluble or free antigens and can only recognize antigens processed and presented by carrier molecules, such as MHC molecules.
Presence of MHCII molecules is a defining feature of APCs that process and present antigens to T cells. Hence, all antigen-presenting cells help in activation of T cells.
Thus, the correct answer is option (b).
Answer:
Option E
Explanation:
Polysaccharides are long chains of carbohydrate molecules, specifically polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages.
Monosaccharides are simple sugars, like glucose. Special enzymes bind these small monomers together creating large sugar polymers, or polysaccharides. A polysaccharide is also called a glycan.
Humans can affect the freshwater flow by polluting the water systems with waste gasoline and other human activities like driving and building factories.<span />
Absolute dating methods determine how much time has passed since rocks formed by measuring the radioactive decay of isotopes or the effects of radiation on the crystal structure of minerals. Paleomagnetism measures the ancient orientation of the Earth's magnetic field to help determine the age of rocks.
Answer:
I believe it is #4! Graphite
Explanation:
Because stone is a heterogenous mixture and graphite is a type of stone!