# AQA A Level Biology Paper 2 Rat Question

Can anyone help me with the working out for this question:
Scientists investigated the production of laboratory rats with the characteristics of
type II diabetes. The scientists used the following method.
They divided the rats into two groups, A and B, and fed them different diets for
2 weeks.
They fed the rats in group A the normal diet containing 12% fat.
They fed the rats in group B a high-fat diet containing 56% fat.
After 2 weeks, they injected both groups of rats with 35 mg kg–1 of the drug
streptozotocin (STZ) to induce diabetes.
1 week later, the scientists determined the mean body mass and mean blood
glucose concentration for each group.
Calculate how many grams of STZ should be injected into a rat with a mass of 230.45 g. Show your working.
Original post by BankaiGintoki
You inject 35mg per Kg.
The mouse weighs 230.45g.
Converted 35mg into g, / 1000.
Weight of mouse/injection =
230.45/(35/1000)

doesn’t match the answer on the mark scheme
Original post by jessmay26xx
doesn’t match the answer on the mark scheme
Never mind, just realised
35mg/Kg
Mouse is 0.23045 Kg
So 35mg/Kg * 0.23045Kg = 8.06575mg = 8.06575 * 10^-3 g.
(edited 1 month ago)
Original post by BankaiGintoki
Never mind, just realised
35mg/Kg
Mouse is 0.23045 Kg
So 35mg/Kg * 0.23045Kg = 8.06575mg = 8.06575
* 10^-3 g.

thank you so much