True, major events like a super volcano's or asteroid strikes can send tons of ash dust and debris into the stratosphere and cause global cooling. <span />
Answer:
B) The normal pH of blood is 6.8 to 7.0.
Explanation:
The blood pH under normal health conditions is between 7.35 and 7.45. Below this range, blood pH is considered more acidic than normal, and it may indicate that the body is eliminating a lower amount of 
than normal, or that there is a decrease in the concentration of 
or accumulation of acid in the blood due to poisoning or disease.
Osmosis. This<span> is the procedure in which water absorption through semi permeable membranes happens at high concentration levels. Semi permeable membranes pertain to tissues found in the plant roots; from there, water will be transported to an area with much lower concentration levels</span>
Answer:
Self-antigens are not recognized and attacked by the T cells.
Explanation:
In immunology, the antigens are those substances which are bound by the antibodies. The antigens can be originated from within the bodies, known as self antigens or from outside the body, known as non-self antigens. The immune system identifies and attacks non-self invaders or the foreign harmful objects present in the body. It does not attack the self-antigens under the normal conditions. This is due to the negative selection of T cells of the thymus.
