11BIO Inquiry Task 3: Osmosis & Red Onion Cells

If the FOV diameter at x4 power is 4 mm, what is this value in µm?

• 400 µm

• 4000 µm

• 40 µm

• 40,000 µm

Which formula is used to calculate the estimated FOV at x100 magnification?

• FOV at higher power = FOV at lower power × (low power / high power)

• FOV at higher power = FOV at lower power ÷ (low power / high power)

• FOV at higher power = FOV at lower power × magnification

• FOV at higher power = FOV at lower power + high power

If the FOV diameter at x40 power is 500 µm, what is the estimated FOV diameter at x100 power?

• 200 µm

• 5000 µm

• 2000 µm

• 200 µm

A student observes red onion cells at x100 magnification. The FOV diameter is 250 µm, and 5 cells fit across. What is the estimated size of one cell?

• 25 µm

• 50 µm

• 100 µm

• 500 µm

What happens to red onion cells when placed in distilled water?

• They shrivel due to water loss

• They swell but do not burst due to the cell wall

• They stay the same size

• They disintegrate

Why do red onion cells not burst when placed in a hypotonic solution?

• Their vacuoles absorb all the water

• The plasma membrane strengthens under pressure

• The rigid cell wall prevents bursting

• The cytoplasm dissolves excess water

What happens to red onion cells in a 10% salt (hypertonic) solution?

• They take in water and swell

• They undergo plasmolysis as the membrane pulls away from the wall

• They stay the same

• They dissolve in the solution

What is an isotonic solution?

• A solution where the concentration of solutes is equal inside and outside the cell

• A solution where water moves into the cell

• A solution where water moves out of the cell

• A solution with no effect on the cell

What would red onion cells look like in an isotonic solution?

• Normal size with the membrane touching the cell wall

• Shrivelled with the membrane pulling away

• Swollen with no visible cell wall

• Transparent and colourless

Why do plant cells look different under a microscope compared to animal cells?

• They have a rigid cell wall and a large vacuole

• They lack organelles

• They have flexible membranes

• They move freely under the coverslip