Identify the feature that is common to both DNA replication and RNA transcriptio
ID: 55779 • Letter: I
Question
Identify the feature that is common to both DNA replication and RNA transcription.
Nucleotides are added to the 5’ end of the newly synthesized strand.
Both RNA and DNA polymerase initiate at origins of replication.
A phosphodiester bond is formed between the 3’ hydroxyl and the 5’ phosphate groups.
Both RNA and DNA polymerase require oligonucleotide priming.
Deoxyribonucleotides are added to the growing sequence.
2. A gene for a hypothetical protein has 5 exons and 4 introns. The exons are 230, 441, 160, 515, and 150 bases long. The length of the introns are 2766, 4185, 4108, and 5373 bases. What is the predicted length of the spliced mature mRNA (excluding the poly A tail)?
A.
2.0 kilobases
B.
5.4 kilobases
C.
16.4 kilobases
D.
1.5 kilobases
E.
1.9 kilobases
QUESTION 2
Which of the following modifications does not occur during mRNA processing in eukaryotes?
A 3' polyA tail is added to mRNA.
mRNA is methylated.
Introns are removed from mRNA.
Exons are spliced together to make mature mRNA.
A methylguanosine cap is added to the 5' end of mRNA.
The following highlighted sequence (gray background; the dots mean any nucleotide sequence of unspecified length), that is transcribed but is not present in mature mRNA, likely corresponds to:
5’ …CCUAAGGUACGG……………………A…………UUUCCCAGGCCUG… 3’
A.
A telomere.
B.
An intron.
C.
An exon.
D.
A promoter.
E.
The polyA tail.
A.Nucleotides are added to the 5’ end of the newly synthesized strand.
B.Both RNA and DNA polymerase initiate at origins of replication.
C.A phosphodiester bond is formed between the 3’ hydroxyl and the 5’ phosphate groups.
D.Both RNA and DNA polymerase require oligonucleotide priming.
E.Deoxyribonucleotides are added to the growing sequence.
Explanation / Answer
Feature that is common to both DNA replication and RNA transcription.
C. A phosphodiester bond is formed between the 3’ hydroxyl and the 5’ phosphate groups.
DNA replication and transcription both involves binding complementary nucleic acids to DNA, thus yielding a new strand of either DNA or RNA.
3. Modifications does not occur during mRNA processing in eukaryotes.
B. mRNA is methylated.
Capping of pre-mRNA iis done by adding 7-methylguanosine to the 5' end. All the other four options are correct.
4. The sequence corresponds to:
B. Introns.
Introns are the sequene present in genes that are transcribed but gets removed during processing and so they donot remain present in mature mRNA.