Answer:
Because T-cell-independent antigens do not activate helper T cells, they fail to induce B cell memory, affinity maturation, or class switching, all of which require help from T cells. They therefore mainly stimulate the production of low-affinity (but high-avidity) IgM antibodies.
Explanation:
Answer:
Fracking and many other humans activities
Explanation:
Physical factors that affect population distribution include altitude and latitude, relief, climate, soils, vegetation, water and location of mineral and energy resources. It is important to note that most of the physical factors influence population distribution only indirectly through climatic conditions.
A. Harbin faces colder air temperatures because it doesn’t receive as much direct sunlight exposure since it is further from the equator.
The gas produced by respiration ,which is carbon dioxide, is the they type of gad that plants need to survive. The principles plants need to survive is carbon dioxide, water, and the sun's solar energy. And the things the give off is oxygen and natural sugar. While we need oxygen to be able to breath the need our carbon dioxide to survive as well, so it works in a cycle.
Veins provide support for the leaf and transport both water and minerals (via xylem) and food energy (via phloem) through the leaf and on to the rest of the plant.
