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.
Answer:B there were soon be insufficient food for the growing human populatio
The key difference between energy flow and matter cycling is that energy flow shows the energy transmission from one trophic level to next trophic level in food chains while matter cycling shows the flow or cycling of elements through the living and nonliving parts of ecosystems
Your answer is burning gasoline. if you think about it, none of the rest of the answers really involve chemicals. ice isnt known as a chemical, and so isnt glass. and if your dent a bumper, it doesnt make sense to add it as a chemical change. so your answer is burning gasoline. hope this helps.
Let’s say John’s age is x. Jim’s age is y. And Dana’s age is z. Then the equation would be:
1.) x + y + z = 167.
We also know that John (x) is 3 years older that Jim (y), so we can make the equation:
2.) y + 3 = x
We know that Jim (y) is 4 years younger than half of Dana’s age (z), so we can make this equation:
3.) z/2 - 4 = y
Now we can combine these equations so that we only have one variable remaining.
The second and third equation can combine to create:
4.) (z/2 - 4) + 3 = x
Then combine the first, third, and fourth equations to have only z as a variable.
5.) ((z/2 - 4) + 3) + (z/2 - 4) + z = 167
Simplify the fifth equation by isolating the variable:
z = 86
Dana’s age is 86. Now plug this into the remaining equations.
86/2 - 4 = 39
Jim is 39. Plug this number into the second equation.
39 + 3 = 42.
John is 42.
FINAL ANSWER:
John = 42
Jim = 39
Dana = 86
