Answer:
A company that makes pain relief medication tests the effectiveness of their own medicine compared to that of three other brands.
This is simply a protective mechanism of the body. A person with blood group A will produced antibodies against blood group B because group B cells are considered foreign bodies to the person and will not be tolerated and vice versa. Group B people have antibodies against group A and will not tolerate group A cells. This is why group A person can only be transfused with group A blood or group O blood. Both A and B have no antibodies against blood group O. Indeed no blood group has antibodies against Blood group and this is why people with blood group O are called universal donors.
Group AB people do not have antibodies against any blood group because both these groups are part and parcel of their body and production of antibodies against either A or B would end up in self destruction of the body. Group AB people are known as universal recipients because they can receive blood from any of the other groups.
Explanation:
polar bear depend on ice so if it gets really hot out of a sudden the melt will melt away and it would be harder for them to live. and for grizzly bears if gets cold all out of the sudden the rivers where they get food turns to ice they'll food which is what they depend on (fish) will die and without food they'll die too.
Answer:
Chromatin
Explanation:
I'm pretty sure this is the answer, let me know if it isn't.
<span>Nitrogen fixation
This process creates organic compounds, including ammonium, that contribute to the growth of a plant in much the way fertilizer does. Many plants have evolved to facilitate nitrogen fixing bacteria in their roots as to promote production of these organic compounds when the soil quality is poor or lacking in these bacteria.</span>