OSMOSIS/DIFFUSION EXAM QUESTIONS

Question 1

A student takes two strips from the epidermis of an onion and places one in distilled
water and the other in concentrated salt solution.

She then uses a camera to photograph a sample of these cells under a microscope.

Suggest why a red onion is often used when carrying out this investigation.

Answer 1

easier to see / no need to stain the onion

Question 2

How is osmosis different from diffussion?

Answer 2

OSMOSIS HAPPENS THROUGH A PARTIALLY PERMEABLE MEMBRANE

Question 3

Name four environmental factors which affect the rate of transpiration.

Answer 3

High humidity (decreases) 
High wind (inc)
High temp (inc)
High/more light (inc)

Question 4

The student wore safety glasses and placed the cubes in a beaker of red dye solution
for five minutes.

Why would he wear safety glasses?

Answer 4

Protect eyes/prevent blindness

Question 5

How does an increase in temperature affect the ROD?

rod- rate of diffusion

Answer 5

temperature (increased);

particles have more (kinetic) energy /
move faster / more movement (will spread out more)/ =inc RAD

Question 6

How does an increase in volume of a dye/water ext affect the ROD?

Answer 6

concentration (increased); increased gradient / more particles =inc ROD

Question 7

ACRONYM for the 4 environmental factors which affect the rate of diffusion?

Answer 7

HoW you Terrible Liar!