Question 21N.2.HL.TZ0.a
| Date | November 2021 | Marks available | [Maximum mark: 4] | Reference code | 21N.2.HL.TZ0.a |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Draw | Question number | a | Adapted from | N/A |
RNA molecules play numerous roles in gene expression and so contribute to variation.
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
[4]
a. ribose drawn as pentagon and labelled sugar/ribose;
b. base drawn with correct link to (C1 of) ribose and labelled base/nitrogenous base;
c. phosphate drawn with correct link to (C5 of) ribose and labelled P/phosphate;
d. two (or more) ribonucleotides drawn with correct link (C3 to C5)
Many candidates were able to draw the structure of an RNA nucleotide and link it correctly by a 5’ to 3’ bond to another nucleotide. The commonest error was to show two strands of nucleotides linked by base pairing, indicating confusion between RNA and DNA.
