where the circuits are toasty and you can always get a warm cup of hot chocolate from
your loving Motherboard. But many of my human friends know these times
as that chilly season called Winter. You may be able to bundle up in sweaters and
roast marshmallows around the fireplace, but what happens to plants and fish during these
cold months? Well, luckily for our aquatic friends, when
the temperature outside falls below the freezing point of water, only the top layers of lakes
or rivers typically freeze. Under the frozen layer, the water remains
in its liquid state and oxygen is trapped below the ice.
This gives fish the environment to survive,
but the colder waters and other conditions -- like less access to food -- cause life
below the ice to slow down. Certain species like cod and flatfish have
a reduced metabolic rate in these times and produce molecules in their bodily fluids that
lower their freezing point so they dont freeze. What about plants? Just like how you prepare for winter by stocking
up on warmer clothes and pumpkin spice lattes, plants also take steps to prepare for the
coming cold. You know when you see the leaves changing
color in Autumn and then falling off? Thats actually part of a process known
as abscission, where most deciduous trees shed their leaves after their colors change
from a loss of chlorophyll, the chemical thats involved in photosynthesis.
With the lack of water and sunlight in the
winter months, theres less photosynthesis and eventually less chlorophyll, allowing
the leaves' other colors to appear. But how do plants know that winter is coming? A certain Game of Thrones character must have
told them, right? Surely youd warn the plants when youre
played by Sean /Bean/. All joking aside, plants appear to have a
stress memory, in that they have the ability to respond more efficiently to a stressor
like cold the second time that its introduced. Many different environmental stressors have
been shown to alter the chromatin and epigenetic marks of plants, providing evidence within
their chromosomes that they do indeed have memories of stress.
This is not downright proof that this /must/
be true, but it does strongly support the theory of plants stress memory. So once plants are all set up for winter,
how do they survive? Well, there is one big thing that the salads
of the world have to worry about more than our forks; they need to protect their cells
from damaging ice crystals, especially ones that would form inside the cells themselves. Many plants guard against this by using a
defensive dehydration mechanism. The plants move water out of the cells and
into the area /between/ the cells.
Intracellular ice formation is generally considered
lethal for plants, but ice /outside/ the cell has the potential to be survived. This is largely due to the cell wall of a
plants cell making it stronger than our puny animal cells. Some trees also add there own delicious twist
to fight winters freezing. The fluid inside the trees cell that used
to be mainly water is changed to contain far more sugars after dehydration.
This sugary sap gives the cells a lower freezing
point, further protecting them from Jack Frosts touch. So what are you doing to help survive the
chills of winter? Let me know in the comments below! Make sure you come back every Monday for a
brand new video. As always, Im Blocko and this has been
Life Noggin. Dont forget to keep on thinking!.
No comments:
Post a Comment