A host cell. Without a host cell, the viruses cannot survive since they don't have any chemical machinery
It should be taken into consideration the presence of frameshift mutations. Frameshift mutation, due to addition or deletion of a base, results in the change of reading frame and consequently in changed protein. But it is known that 3 nucleotides on mRNA code for the specific amino acid. If the number of inserted or deleted nucleotides is 3, it will result in the absence<span> of only 1 amino acid which is not expected to drastically change protein sequence.
Knowing all this, it can be concluded the following:
</span>
<span>-/-/+/-/- <u>OK </u>- Due to 4 deletions and 1 insertion, effectively only 3 nucleotides are missing.
</span>+/-/+ <u>Not OK</u> - Due to 1 deletion and 2 insertions, effectively only 1 nucleotide is added leading to the frameshift mutation.
+/-/+/- <u>OK </u>- Due to 2 deletions and 2 insertions, a number of nucleotides remain the same.
+/+/-/+ <u>Not OK</u> - Due to 1 deletion and 3 insertions, effectively only 2 nucleotides are added and the frameshift mutation occurs.
-/+ <u>OK </u>- Due 1 deletion and 1 insertion, a number of nucleotides remain the same.
<span>- <u>Not OK</u> - Due to 1 deletion, the frameshift mutation occurs.
</span>-/-/-/-/-/- <u>OK </u>- <span>Due to 6 deletions, it will be deleted 2 amino acids and the protein will be nearly normal.</span>
<span>+/+/+ <u>OK </u>- Due to 3 insertions, 1 amino acid will be added in excess.
</span>-/- <u>Not OK</u> - Due to 2 deletions, the frameshift mutation occurs.
It is four times dimmer than the sun.(4)
First one and the third one
Answer:
By Controlling transcription
Explanation:
Prokaryotic cells regulate their gene expression by controlling the amount of transcription. This is the only way of regulating the gene expression.
Unlike the prokaryotic cell, in eukaryotic cell, different compartments were formed for carrying out different cellular processes. Later on, transcription and translation were physically separated and were carried out in two different cellular compartments
