KA5: Transport Systems - Plants Flashcards
What do plant organs include
Leaves
Roots
Stem
What is water used for
Photosynthesis
Support
Transport of minerals and sugar
Cooling through evaporation
How to roots absorb water and minerals?
Through their root hairs
Why do root hairs have a large surface area?
So that more water and minerals can be absorbed
How do water and minerals diffuse into root hairs
From the soil by osmosis
Where are the water abd minerals transported to
Dead cells called xylem
What does the xylem do
Transports water and minerals to the rest of the plant through the stem
How does xylem push the water through to the leaves?
Maintaining high pressure
How are xylem structured?
With rings of lignin
What does lignin do?
Allows xylem to withstand changes in pressure as water moves through the plant
What is the function of the vein (plants)
Contains xylem and phloem to allow the transport of water to the leaves and transport of sugar away from the leaves
What is the function of the mesophyll cells?
Has lots of chloroplasts for photosynthesis
What is the function of the stomata
Pores that allows carbon dioxide to enter and water and oxygen to leave
What is the function of the guard cells
Change shape to open or close stomata
What is the function of the upper epidermis
Top of leaf
What is the function of the lower epidermis
Bottom of leaf
What is transpiration?
The process of water moving through a plant (starting from the roots) and its evaporation through stomata
How does transpiration work?
Water enters roots into xylem by osmosis
Water tension pulls it up to the leaves
Water tension pulls water from vein to mesophyll cells
Water evaporates
Water vapour diffuses out of the stomata
What enters and exits stomata
Carbon dioxide enters for photosynthesis
Oxygen leaves as a by-product
When are stomata open and why?
During the day while it is light to allow carbon dioxide to enter for photosynthesis
How does the stomatal pore open?
Guard cells gain water and swell up becoming turgid
When does the stomata close and why?
At night due to darkness as photosynthesis cannot occur
How does the stomatal pore close?
Guard cells lose water and become flaccid
What is a potometer?
Used to measure transpiration
How is the rate if transpiration affected?
Wind speed
Humidity
Temperature
Surface area
Where is sugar made during photosynthesis
Palisade mesophyll
Where is sugar transported to? (plant)
Up and down the whole plant through living phloem
What is phloem made up of
Seive plates and associated companion cells
What are phloem
Continuous to allow sugars to pass through each sieve tube quickly
What allows phloem to be continuous
Cytoplasm between each sieve tube
What do companion cells do?
Provide energy for sieve cells
What is sugar used for (plants)
Growth
Stored in fruit
Stored as starch
Supply energy
