Answer 1:
Growth is a pretty complicated process, and
requires a lot of energy. All living things grow,
and thus all living things need energy for growth
(and for a lot of other things, but growth is a
biggie). As I'm sure you know, animals get their
energy from food: we eat organic carbon
(carbohydrates, proteins, fats) and through a
process known as the Krebs cycle get energy
by converting the organic carbon to inorganic
carbon (carbon dioxide, CO2). Plants
also get their energy for growth from the Krebs
cycle. But as I'm sure you know as well,
plants don't eat (with the exception of a few
strange plants like the Venus flytrap). So how
do plants get the energy they need for growth?
They harness it from sunlight in a process known
as photosynthesis.
Photosynthesis is sort of the reverse of the
Krebs cycle: it stores energy by converting
inorganic carbon (carbon dioxide) into organic
carbon (glucose, for example). This stored energy
(organic carbon) enters the Krebs cycle and this
is how the plants get the energy they need for
growth and survival. So the answer to your
question is no, plants can not grow or survive
without photosynthesis.
Plant growth, and certainly plant survival, may
occur without photosynthesis over very short
periods. (Be aware that growth and survival are
different: growth implies an increase in size or
weight, so things can survive and not grow.) If
you stick a fairly large plant in the dark, it
won't die immediately. It may even grow a little
bit, if it has some stored energy. Just like if
you ate the biggest meal of your life and then
stopped eating immediately, you might still put on
weight initially from the huge meal (you'd grow),
but eventually you would start to loose weight,
and finally you'd starve to death. So the plant
might grow a bit in the dark, without
photosynthesis, from stored reserves, and might
continue to survive for a couple weeks or more
without growing, but in the long term the plant
will not be able to grow or live without
photosynthesis and would eventually die. Click Here to return to the search form.
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