Answer:
Explanation:
Helium is the second most abundant element in the universe, but here on earth, it's rather rare. Most people guess that we extract helium from the air, but actually we dig it out of the ground. Helium can be found in certain parts of the world, notably in Texas, as a minor component in some sources of natural gas.
Helium is generated underground by the radioactive decay of heavy elements such as uranium and thorium. Part of the radiation from these elements consists of alpha particles, which form the nuclei of helium atoms. ... Helium can also be produced by liquefying air and separating the component gases
When the gas contains more than about 0.4% helium by volume, a cryogenic distillation method is often used in order to recover the helium content. Once the helium has been separated from the natural gas, it undergoes further refining to bring it to 99.99+% purity for commercial use.
In brain chemistry, synapses are very important. Synapses have a number of different forms but have two basic varieties:. excitatory and inhibitory. Excitatory synapses make it more likely that a neuron will send its message to other neurons, whereas inhibitory synapses make it less likely that a neuron will send its message.
Explanation:
MNI is the Minimum Number of Individuals required to test and validate an experiment or a case. It is used to determine the minimum number of people or individual involved in a case or an experiment.
In forensic anthropology, MNI is used to determine the least number of people required to account for the bones present. The MNI chosen is not necessarily will be right while solving a case. The investigators might night to consider different set of individuals.
Answer:
C. Mutation.
Explanation:
The mutation is the source of all genetic variation. There are two types of mutations. One is the natural mutation, and another is the artificial mutation. The natural mutation occurs due to the environmental cause, and humans using various mutagens do artificial mutations.
These two types of mutations always bring variation in any organism. This variation can be positive or can be negative too. Natural mutation is not possible to control so that anything can happen. Either positive or negative changes can occur. But in the case of artificial mutation, in 90% cases, positive results come in genetic variation.
Your answer should be A. Nucleolus.
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