Sub Zero Temperatures - Plants Flashcards
____ inside plants will kill it.
Ice
Define Cold Hardiness.
drawing out excess water from leaves with evaporation so they don’t freeze as easy.
What happens inside the cell through cold hardiness because water has been drawn out?
Solute concentration increases since water is drawn out.
Higher viscosity -> Less freeze prone
What is substance is added through cold hardiness to help prevent freezing?
Sugar
What happens to plant cell walls through the process of cold hardiness?
How do these two things help?
They become more flexible and more permeable.
- flexibility allows the cell to bend as ice forms between the cells
- permeability allows sugars and water to pass though easier.
What is the process of becoming cold hardy called?
Acclimation
What triggers acclimation (2 stages)?
1st Stage: phytochromes detect photoperiod change and cause cells to go dormant and the plant to become more responsive to lower temperatures.
2nd Stage: cold hardiness and allows ice to freeze inbetween cells
What is a phytochrome?
light sensitive photopigment in plants
What is photoperiod?
the light available during the day.
Why is retaining needles a problem?
Damage by solar radiation
What are Xanthophyll Pigments?
enable chlorophyll to use the sun’s energy to create heat and not to photosynthesize
What unusual adaptation does skunk cabbage do?
Melt the snow around it
Why are sunny days in winter bad for plants?
Desiccation
Define desiccation.
Plants dying from low humidity
Some ways to prevent desiccation (3).
Fuzzy underside of leaves to trap moisture.
dropping leaves in winter so they don’t expel water due to their high surface area.
becoming cold hardy
