Calibration and Biological Drawings

Question 1

Outline the criteria for constructing a biological drawing.

Answer 1

1. Large as possible
2. No shading, colours or overlapping lines
3. Add title, scale and labels
4. Only draw what’s in the img

Question 2

Why do light microscopes need to be calibrated?

Answer 2

1. Ensures the same sample gives the same results w diff microscopes
2. Diff micros can give diff readings if not calibrated

Question 3

What is an eyepiece graticule?

Answer 3

1. Glass disc in eyepiece used to measure sample
2. Has 100 divisions + no units
3. Relative size of divisions inc w mag
4. Calibrated w stage micrometer

Question 4

What is a stage micrometer?

Answer 4

1. Microscope slide w acc scale in micrometres

2. 100 divisions = 1mm

Question 5

What is the formula for calculating 1 graticule division?

Answer 5

1 graticule division = no of micrometres/ no of graticule divisions

Question 6

Outline the process of calibration.

Answer 6

1. Put in stage micro + graticule
2. Align graticule scale w stage micro
3. Replace stage micro w specimen slide
4. Use calibrated graticule to measure specimen