This will help http://www.answers.com/Q/What_is_the_result_of_the_diversity_of_organisms_present_on_earth
The answer is; cell surface receptors that are recognized as antigens by the recipient's immune system.
Therefore the organ is attacked as a foreign substance . This is why organ transplants are given by the closest family member to reduce the antigen variability that causes transplant rejection. Tissue typing is done to ensure that the organ or tissue is as similar as possible to the tissues of the recipient.
Answer:
1 = A
2 = B
3 = B
Explanation:
1) Black holes occur when really big stars collapse on themselves. And, in order to get big, the star has to be an old one.
2) A black hole is something huge that swallows up everything, while a protostar is just the very beginning of a star.
3) Scientist can't truly know for sure, but they can infer about them due to the effects of the surrounding areas.
Throwing a ball is an example of kinetic energy. I do not have any proof or any reasons, but for now I just know that it's kinetic energy. You can also look it up and you'll see the answer automatically. Hope this helps :) If you want any proof, please feel free to ask me thru contact :)