the Ground Up
perhaps most, of the visitors to this site will find this series
too elementary to be worth reading. Please don't dismiss it too
quickly, though - I often find some new idea, or way of thinking
about something, in the simplest sounding articles.
you have drawings posted on your refrigerator? If not, do you remember
them? Stick figures of people, houses with two or four windows and
a door, and smoke coming out of the chimney. What about the plants?
they looked at all like this, then they are not a bad way
to start talking about what does what in the plant, and why.
And from that, eventually to see what each part needs in order
to carry out its function in the scheme of things.
plant is a system, in the modern usage of that term as a group
of things that are interdependent. Each part must work in
order for the whole to succeed, and the efficiency with which
each part does what is required of it by the whole, determines
how successful the whole will be. A big jump from stick pictures
to a simplistic definition of systems theory!
easy to understand, though. In our stick picture we see the leaves
receiving sunlight. They use this energy to produce simple sugars
in the process called photosynthesis. These simple sugars can be
used by the plant to release the energy stored in them to fuel all
of the plant's activities. They can be carried round to all parts
of the plant, and used wherever they are needed, and they may themselves
be the basis for any of the far more complex compounds that are
used by the plant to build itself, or to control all of its activities.
stem of the plant holds the leaves in the best position possible
for the leaves (the photosynthetic factories) to receive energy
from the sunlight. It is also a transport area-may I use a plumbing
analogy- the main stack that moves things around the plant. One
part of the plumbing carries the products of the leaf activity away
from the leaves, and another, separate but parallel, system carries
everything from the roots up to the leaves and other parts of the
brings us to the roots, which are the physical connection to the
ground that holds the trunk upright, but which also are in intimate
contact with everything that is going on in the soil. Most of the
water, and most of the chemicals that the plant uses to make its
complex materials, enter the plant through the roots.
here is the system: the roots hold the plant in place and take up
the water and nutrients that the plant needs; the stem or trunk
carries these around the plant and also pushes the leaves up to
where they can perform their job; this job is to convert energy
received from the sun into a transportable, storable, chemical form
that is the fuel for everything that the plant does.
why it is fair to regard the plant as a system which only works
if each part of it is working properly?
I almost forgot the flower. this is the part that must do whatever
it takes to make seed, and then to spread these seed around to make
more individuals of the plant. A series of whole complex stories
there. Let me leave this with the thought that to a seed, everything
the plant does is just a way of producing more seed like itself.