Question 19M.1A.HL.TZ2.13
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.HL.TZ2.13 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Determine | Question number | 13 | Adapted from | N/A |
A nucleotide containing dideoxyribose is shown.
What is the reason for the use of dideoxyribonucleotides to terminate sequences in base sequencing?
A. Nucleotides cannot form 5′ to 3′ linkages with dideoxyribonucleotides.
B. Nucleotides cannot form base pairs with dideoxyribonucleotides.
C. Dideoxyribonucleotides cannot form hydrogen bonds with deoxyribose.
D. Dideoxyribonucleotides do not have all four nitrogenous bases.
[1]
A
This question discriminated well. In Topic 7.1 it states that candidates should be able to understand the use of nucleotides containing dideoxyribonucleic acid to stop DNA replication in preparation of samples for base sequencing. Some candidates believed dideoxynucleotides failed to form base pairs with nucleotides, showing lack of understanding of the sequencing process.
