If Polaris were to go supernova today, no one currently on Earth ever know it happened because it would take 434 light years to reach the Earth
Explanation:
The Polaris or the North Star that we can see at the North Pole of the Earth in the night historically dates back to 434 years in the past. If the Polaris becomes a supernova or if it dies now, it will take 434 years in the future from now to know about it.
This is simply because ‘one light year is the distance traveled by light in one year’. Hence currently, one cannot know about what happened to the Polaris supernova even if it happens now.
Answer:
all of the above
Explanation:
Epigenetic alterations are modifications of the genome transmitted during cell division, which do not involve changes in the DNA sequence, are hereditary and are capable of modifying gene expression. In addition, they are temporary modifications that allow DNA to be transcribed and have the ability to move histones to open or close a chromosomal region. There are three main mechanisms of epigenetic alterations: DNA methylation, histone modifications and genomic imprinting.
In eukaryotic cells the DNA can be found in the nucleus mainly. so DNA replication takes place in the nucleus during the S phase of the cell cycle.
Also in eukaryotic cells there are mitochondria and chloroplasts (plants) and these have circular DNA and they also get replicated (according to their own mechanism).
Prokaryotic cells don't contain a nucleus. They do not contain DNA in the cytoplasm and thus the DNA replication will take place here.
I really hope this helps!
