Question 18M.2.HL.TZ1.4
| Date | May 2018 | Marks available | [Maximum mark: 5] | Reference code | 18M.2.HL.TZ1.4 |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Distinguish, List, Outline | Question number | 4 | Adapted from | N/A |
Sickle cell anemia is due to a single base substitution in DNA. Using the diagram, outline how this translates into the production of an abnormal hemoglobin molecule by completing the spaces labelled I, II and III.
[2]
a. I: GUG
AND
II: CAC
b. III: Val/valine
Both required. Do not accept GAG to GTC.
DNA codes for the amino acid sequence of polypeptides. List two other functions of DNA.
[2]
a. promotion/repression/regulation of gene expression
b. introns (have functions in regulation of gene expression)
c. telomeres (form caps at the end of chromosomes)
d. coding for tRNAs/rRNAs
e. allows genes/traits/heritable characteristics to be passed to offspring
Distinguish between the purpose of free and bound ribosomes.
[1]
free ribosomes produce proteins for use inside the cell/cytoplasm whereas bound ribosomes produce proteins for secretion/for use outside the cell/for use in lysosomes