DNA is copied during mitosis and when the two resulting copies of DNA are compared they are found to contain the same order of nucleotides is not the result of mutation in the DNA sequence of an organism.
Explanation:
Mutation is the process
It is caused by certain chemicals called mutagens or by environmental factors.
In mutation the nucleotide get change which eventually changes the protein product.
In mutation purine base gets mutated to purine base and pyrimidine base gets mutated to pyrimidine only.
A single change in nucleotide is called point mutation and the effect occurring because of it is called frame shift mutations.
In S phase there are checkpoints which ensure that DNA replication is accurate and when mitosis follows it equal distribution of DNA takes place between the two daughter cells hence no mutation will takes place.
Answer:
They are in a fixed ratio
Explanation:
in the nucleolus ribosomes are made.
the same goes for the other
Answer:
The correct answer is - 6 chromatids.
Explanation:
Prophase is the stage in the cell cycle that is known for the condensation and disappearance of the nucleolus. In this stage chromosome become more compacts and the sister chromatids are still together and not separated. These sister chromatids are joined together with the centromere.
Centromere do not allow sister chromatids to move away and makes it intact. The number of centromere is the number of chromosme present in the prophase and half of the sister chromatids that means if there us 3 centromere than the number of sister chromatids will be 6.
