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.
Answer:
Number of wolves, and harshness of winter.
Explanation: I took the test
Answer:
There are three types of RNA involved in protein synthesis:
messenger RNA (mRNA)
transfer RNA (tRNA)
ribisomal RNA (rRNA).
Explanation:
All three of these nucleic acids work together to produce a protein. The mRNA takes the genetic instructions from the nucleus to the cytoplasm, where the ribosomes are located.
Answer:
Nerve agent
Explanation:
A nerve agent is a chemical in which on exposure to humans affects the functioning of the nervous system. These chemicals are known to disrupt the process by which messages are transferred to the organs from the nerve. This disruption occurs by blocking the activity of acetylcholinesterase, which is responsible for the catabolism of a neurotransmitter, acetylcholine.
On exposure to a nerve agent, the muscles of the body become paralyzed and early symptoms is production of excess mucous such as in runny nose, pupil constriction and also difficulty in breathing.
These agents are sometimes used in chemical warfare. Examples include sarin, tabun etc.
<span>The distance traveled divided by the time is called the speed, while the displacement divided by the time defines the average velocity. If the positions of the initial andfinal points are known, then the distance relationship can be used to find the displacement.</span>
