| Date | May 2013 | Marks available | 2 | Reference code | 13M.3.SL.TZ2.17 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Discuss | Question number | 17 | Adapted from | N/A |
Question
Explain how Gram staining is used in microbiology.
Discuss the possible consequences of gene therapy.
Markscheme
a. Gram staining is used to classify bacteria/Eubacteria;
b. cell wall structure determines how Gram stain is received;
c. bacteria termed as Gram-positive or Gram-negative;
d. Gram-positive bacteria appear purple;
e. Gram-negative bacteria (stain less intensely and) appear pink/red;
most attempts have been unsuccessful/caused harm or death/caused emotional trauma/conflicts of interest/ethical issues;
might alleviate (genetic) condition / correct a (genetic) defect;
Examiners report
Most of the well prepared candidates knew about the varied structural features among viruses in a, could explain how the gram stain is used in b and that most attempts at gene therapy have been unsuccessful, although it could potentially correct a (genetic) defect.
Most of the well prepared candidates knew about the varied structural features among viruses in a, could explain how the gram stain is used in b and that most attempts at gene therapy have been unsuccessful, although it could potentially correct a (genetic) defect.
