DP Biology (first assessment 2025)

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Question 19N.1B.SL.TZ0.b

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Date November 2019 Marks available [Maximum mark: 2] Reference code 19N.1B.SL.TZ0.b
Level SL Paper 1B Time zone TZ0
Command term Outline Question number b Adapted from N/A
b.
[Maximum mark: 2]
19N.1B.SL.TZ0.b

Outline the measurements which would need to be taken to determine the activity of the beta-galactosidase at different pH values.

[2]

Markscheme

a. test samples for the concentration/amount of products/glucose/fructose/substrate/lactose ✔ Accept use Benedict/Fehling to see change in amount of reducing sugar

b. take samples of the reaction mixture at regular/timed intervals ✔ Must indicate that samples are taken at timed intervals

c. repeated measurements «at the different pH values» ✔

d. measure independent/controlled/standardised/variables / temperature ✔

Syllabus sections