The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm), yet short, vein that receives venous return from the upper half of the body, above the diaphragm.
This is an illustration of the reflex arc.
Answer:
Explanation:
When a substance has the capacity to disrupts the genetic compositions (DNA) of the organisms, to the extent that it makes the particular organism genetic materials prone to genetic mutation,( random changes in the genetic composition) such group of substances are called Mutagens.
ionizing radiation,radioactive decay are some examples of of physical mutagens, while biological mutagens examples include viruses and bacterial. Chemical mutagens are Benzene compounds,bromine,aromatic amines,sodium Azide.
They exerts their negative effects
by disrupting gene expression sequence of transcription, translation, or changed the nucleotides sequence of the DNA leading to deletion, addition, subtraction of genetic bases.Some may make chromosomes to be unstable, disrupting the structure
Although some mutagens can cause cancer, that is they are mutagens. not all mutagens carcinogenic.This is because the Mutagenic effects depends on the metabolites present in the cells of the organisms.
Having a controlled group is very important.
Reason: If scientists did not have a controlled group then, they would have data for the test but they might know if the results changed or not. Scientists need a controlled group because the controlled group is like the original. They need the original group to help them know what improved or did not improve.
For example, if you were testing whether or not different types of music helps with studying, then you will need a group that does not listen to music so you can know if different types of music actually improve or just make studying worse.
Having a controlled group helps you know the difference between observations in a easier way. The controlled group is not something people should ignore. It might seem useless at first but, when a person starts to finish up their project or test then, they will understand why a controlled group is important. By the time they do, it might be too late so make sure you people use a controlled group(Especially in the Science Projects).
(Hope this helps : ) )
The correct answer is <span>C. You cannot view live specimens because the necessary preparation kills cells. </span>
The answer is pretty self-explanatory. Unlike it, regular microscopes can view living creatures such as bacteria or similar.
