Microscope review 2

When observing a specimen under the microscope with objective lens 4x, 10x and 40x, which of the following cannot be a possible total magnification of a specimen?

• 40x

• 60x

• 100x

• 400x

What is the correct sequence for viewing a specimen under the microscope?

(i) Place the specimen on the stage

(ii) Adjust the objective lens to the lowest power

(iii) Adjust the coarse adjustment knob

(iv) Adjust the fine adjustment knob

(v) Adjust the diaphragm

• (i), (ii), (v), (iv), (iii)

• (ii), (i), (v), (iv), (iii)

• (ii), (i), (v), (iii), (iv)

• (v), (ii), (i), (iii), (iv)

A specimen was viewed under a 40x objective lens. What is the actual length of the cell?

• 0.1 µm

• 0.133 µm

• 133 µm

• 100 µm

When preparing a specimen, why do we lower the cover slip at an angle?

• To prevent the cover slip from breaking.

• To prevent the specimen from being damaged.

• To remove air bubbles that may be trapped.

• To remove any excess stain that may be trapped.

Why do we need to stain the onion cell with iodine but not the hydrilla leaf?

• To ensure the cover slip does not compress the onion and damage the cells.

• To hydrate the onion cells as unlike hydrilla, onion is not an aquatic plant.

• To sterilise the onion from bacteria in the environment.

• To visualise the onion better as it is colourless.