Osmosis & Plant Transport Flashcards by Holly K

Concentration gradient 

3 marks

Difference in concentration between;

2 solutions
different cells
or cells + a surrounding solution.

How well did you know this?

Not at all

Perfectly

Flaccid

1 mark

Lacking turgor.

Lacking in stiffness or strength. Soft + floppy.

How well did you know this?

Not at all

Perfectly

Humidity

2 marks

Amount of water vapour in the atmosphere measured as a percentage.

How well did you know this?

Not at all

Perfectly

Potometer

1 mark

Device used to measure the rate of water uptake by a plant.

How well did you know this?

Not at all

Perfectly

Selectively Permeable

1 mark

Property of a membrane that controls the movement of molecules depending on their size.

How well did you know this?

Not at all

Perfectly

Transpiration

2 marks

Loss of water from leaves by evaporation through the stomata. 

How well did you know this?

Not at all

Perfectly

Turgid

1 mark

Having turgor; enlarged and swollen with water. 

How well did you know this?

Not at all

Perfectly

Visking tubing

2 marks

An artificial, partially-permeable membrane used in osmosis + diffusion experiments.

How well did you know this?

Not at all

Perfectly

(Selectively/) Semi-permeable membrane

2 marks

Allows some small substances to pass through

- Prevents larger substances.

How well did you know this?

Not at all

Perfectly

Cell wall permeability

2 marks

Fully permeable - does not control what enters + leaves cell.

How well did you know this?

Not at all

Perfectly

Cell membrane structure

2 marks

Rigid - provides a plant cell with support + keeps non-woody plants upright.

How well did you know this?

Not at all

Perfectly

Osmosis in Cells depends on

1 mark

Concentration of water surrounding it.

How well did you know this?

Not at all

Perfectly

Animal cells - osmosis

2 marks

When water moves into an animal cell - cell membrane stretches + cell gets bigger.

How well did you know this?

Not at all

Perfectly

Example of an Animal Cell

1 mark

Red blood cell

How well did you know this?

Not at all

Perfectly

Lysis

1 mark

Cell membrane bursts due to excess water intake.

How well did you know this?

Not at all

Perfectly

Membrane stretches - gets bigger, then bursts due to excess water intake

(1 mark)

Lysis

How well did you know this?

Not at all

Perfectly

Turgidity in plant cells

5 marks

Water diffusing into a plant cell = vacuole gets bigger, pushing cell membrane against the cell wall.

Force of this increases turgor pressure within cell making it firm or turgid.

How well did you know this?

Not at all

Perfectly

When vacuole expands cell membrane is pushed against cell wall - pressure created by cell wall during osmosis in the Cells…does what?

(2 marks)

Stops too much water entering + prevents cell lysis.

How well did you know this?

Not at all

Perfectly

If plants do not receive enough water

2 marks

Cells cannot remain turgid + plant wilts.

How well did you know this?

Not at all

Perfectly

Cells that are not turgid

1 mark

Are flaccid.

How well did you know this?

Not at all

Perfectly

Plasmolysis

1 mark

When too much water moves out of a plant cell + cell contents shrink - pulling the cell membrane away from the cell wall.

How well did you know this?

Not at all

Perfectly

Cell state unlikely to survive

1 mark

Plasmolysed cell

How well did you know this?

Not at all

Perfectly

Transpiration

4 marks

Evaporation of water from spongy mesophyll cells

- followed by diffusion of water through the air spaces + out of the stomata.

Transpiration stream

2 marks

Water in a plant that exits the leaf into the atmosphere

providing a continuous stream of water.

Importance of transpiration stream | 5 marks

Provides; - leaves with continuous supply of water (for photosynthesis). - plant cells with support from turgor. - water for transpiration. Continually transports minerals from roots, to leaves + other parts of plant.

If water availability is limited - plants... | 1 mark

Will need to reduce transpiration.

How to reduce transpiration. | 2 mark

Stomata close (lower side of leaf)

Effect of surface area (non-environmental factor) on transpiration. (2 marks)

Smaller leaves will contain less stomata - causing a decrease in transpiration.

Effect of wind speed on transpiration. | 3 marks

Higher wind speed - increase rate of evaporation Causing an increase in transpiration.

Effect of temp on transpiration. | 3 marks

Higher temp - will increase the rate of evaporation Causing an increase in transpiration.

Increase rate of evaporation | 1 mark

Increased rate of transpiration.

Effect of humidity on transpiration | 3 marks

Higher humidity level - will reduce the rate of evaporation causing a decrease in transpiration.

Decreased rate of evaporation | 1 mark

Decreased rate of transpiration.

Effect of light intensity on transpiration. | 3 marks

Darkness will cause the stomata to close - causing a decrease in transpiration.

Smaller leaves will contain less stomata causing a decrease in transpiration: How can we change this factor Experimentally? (1 mark)

Remove leaves.

Higher wind speed will increase the rate of evaporation causing an increase in transpiration: How can we change this factor experimentally? (1 mark)

Use a fan.

Higher temp will increase the rate of evaporation causing an increase in transpiration. How can we change this factor experimentally? (1 mark)

Use a heater.

Higher humidity level will reduce the rate of evaporation causing a decrease in transpiration: How can we change this factor experimentally? (2 marks)

Place a clear, plastic bag over the plant shoot.

Darkness will cause the stomata to close causing a decrease in transpiration: How can we change this factor experimentally? (1 mark)

Use a lamp.

If less is water being lost through transpiration. | 1 mark

Plant will absorb less water at the roots.

Potometer | 2 marks

Apparatus designed to measure water uptake in a leafy shoot.

2 types of potometer | 2 marks

Bubble potometer + Weight potometer.

Water is transpired from ______ . | 1 mark

Leaves

_____ absorbs water from the potometer. | 1 mark

Shoot

What can be used to calculate the rate of water uptake? | 2 marks

Distance the air bubble moves in a certain period of time

What can the movement of air bubbles (under time constraints) be used to measure? (1 mark)

Rate of water uptake by Plant.

Potometer - the apparatus | 7 marks

Set up under water - prevent entry of unwanted air bubbles. Junction between shoot + potometer is sealed - prevent air leaks. Apparatus reset using reservoir/syringe so water uptake in the same leafy shoot can be measured – making the investigation more reliable.

What is the junction between the shoot and potometer sealed usually sealed with? (1 mark)

Petroleum jelly

Why is the potometer set up under water? | 1 mark

Prevent entry of unwanted air bubbles.

Potometer is reset using the 1._________ or 2._______ so that water uptake in the same leafy shoot can be measured. (2 marks)

1. Reservoir | 2. Syringe

Why is the junction between the shoot + potometer sealed? | 1 mark

Prevent air leaks.

Examples of factors that the potometer can investigate | 4 marks

Light intensity, humidity, temp + wind speed

When investigating the effect of an environmental factor what is important? (1 mark)

All others factors are kept constant to ensure the experiment is valid.

Weight potometer - how to use: | 6 marks

Apparatus + plant weighed + left for a period of time. When reweighed the amount of water lost by the plant can be calculated. Top pan balance that measures to 2 decimal points provides great accuracy.

What provides great accuracy when using a weight potometer? | 1 mark

Top pan balance that measures to 2 decimal points.

Potometer can measure the amount of water taken up by a leafy shoot but cannot provide (3 marks)

An accurate value for the amount of water transpired - because some water will be used in photosynthesis + to provide turgor.

Potometer can measure | 1 mark

Amount of water taken up by a leafy shoot.