DP Biology (first assessment 2025)

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Question SPM.1B.SL.TZ0.c

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Date May Specimen-2023 Marks available [Maximum mark: 1] Reference code SPM.1B.SL.TZ0.c
Level SL Paper 1B Time zone TZ0
Command term Suggest Question number c Adapted from N/A
c.
[Maximum mark: 1]
SPM.1B.SL.TZ0.c

Suggest a reason for using a lower power objective lens when first focusing on a slide under the microscope.

[1]

Markscheme
  1.   it is easier to find the specimen using a low power objective lens
      OR
      there is a larger field of view/depth of focus;
  2.   it is easier to locate the most interesting part of the specimen with a low power objective lens;
  3.   most microscopes are calibrated so that once in focus using the low power objective lens they will be close    to focus using the higher power, so this helps focusing;
  4.   reduced risk of cracking the slide;

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