B2 - Transport in Plants and Prokaryotes Flashcards
(25 cards)
What aids transport in all living organisms?
Diffusion
Osmosis
Active transport.
What happens to substances in single celled organisms including prokaryotes?
Substances diffuse in and out of them across their partially permeable membranes.
Why are specialised exchange surfaces needed?
In multicellular organisms diffusion across the outer surface is more difficult because some cells are deep inside the organism.
What do plants use and produce when the photosynthesis?
They use Carbon dioxide from the atmosphere and produce oxygen as a waste product
How do CO2 and O2 move in and out of plants and their cells?
By diffusion
Explain why CO2 moves into a leaf during photosynthesis.
The plant uses up lots of CO2 during photosynthesis so there is hardly any left inside the leaf. More CO2 moves into the leaf by diffusion.
What are the tiny pores on the lower leaf called?
Stomata
What do stomata do?
Let gases like CO2 and O2 diffuse into the leaf. They also allow water vapour to escape.
What is transpiration?
It’s how the water vapour escape out of the stomata on the lower parts of the leaf.
Where do molecules need to be to cross a membrane?
Next to it.
How do plant take water and ions on?
Through their roots.
What do plant need mineral ions for?
Growth
What do plants need water for?
Photosynthesis.
What do plant take on through their roots?
Water and ions.
What is each branch of a root coved in?
Millions of microscopic root hair cells
What is the purpose of the root hair cells?
They give the plant a big surface area to absorb water and mineral ions from the soil.
What does a large surface area mean?
Lots more molecules closer to the membrane.
What do plants need to make proteins?
Nitrogen
Where do plants get nitrogen from?
From nitrate ions in the soil.
How do mineral ions move into root cells?
Active transport
How is energy provide for active transport of ions?
Using molecules of ATP
Why do cell need to provide energy to actively transport minerals through the cell membrane?
Because the concentration of the root hair cell is usually high than in the soil
How is water drawn across the partially permeable membrane?
By osmosis
Why does the plant use osmosis to draw in water?
Because there is usually a higher concentration of water in the soil than in the plant.