Without plants, we would not be here. Life on earth as we know it wouldn’t exist.
Photosynthesis is the basis of most food webs. Plants are called primary producers, and they’re at the base of all ecosystems. Plants harvest energy from the sun, and begin its path through ecosystems.
Everything in ecosystems is recycled, except energy.
In the process, plants create biomass.
Cellulose is the most abundant macromolecule on earth.
RUBP Carboxylase is the most abundant protein on earth.
The evolution of photosynthesis some time before 3.5 billion years
ago
had a profound impact on evolution of life, because it
produced OXYGEN. It changed our atmosphere
completely,
affected earth’s geology, and changed the way life conducts itself. It
made large organisms like US possible. It also
changed
the entire planet, geologically.
The BIG PICTURE:
Photosynthesis, and thus THE SUN, drive ecosystems and evolution
as surely as it drives the life of individual plants
THE ESSENCE OF PLANTNESS
PLANTS AND ANIMALS SHARE MANY CHARACTERISTICS.
1. Both are EUKARYOTES
2. Both do SELECTIVE EXCHANGE OF MATERIALS WITH THE ENVIRONMENT
3. Both require ENERGY TRANSFORMATIONS TO SURVIVE
4. Both GROW
5. Both REPRODUCE
6. Both SENSE AND RESPOND TO THE ENVIRONMENT
7. Both DIE
BUT, we tend not to hold plants in high regard. Why not????
1. Chauvanism, for one thing.
E.g., plants are not directly linked to human disease.
Yes, they’re important for food, but we don’t attach as deep
a meaning to that as disease. We take it for granted.
2. But also more subtle, ‘philosophical’ reasons.
Take any plant....
What if I yank a leaf off?
What if I did the same thing to somebody's arm? HORRORS!!
Why the difference in your response?
Animals, and especially humans, have emotions, feelings, thoughts
etc.
We don’t see plants as sentient beings, and therefore as ‘highly’
evolved as us.
It’s a matter of LIFE STYLE.
Plants are PHOTOAUTOTROPHS.
They can synthesize all the organic molecules needed for life,
and extract energy to do so from...... WHERE?
They are ‘self-feeders’, or collectors, concentators,
PRODUCERS.
What about animals? What are they called??? CHEMOHETEROTROPHS.
What does that mean?
They are also called ‘scatterers’.
Animals usually must pursue food -- they're mobile
-- and this requirement is reflected in everything about them!
Organ systems, physiology, behavior, reproduction.
Plants have a fundamentally different life style.
Again, they’re photoautotrophs. AND, they're stationary, or
sessile.
They require LIGHT for energy.
Their whole MORPHOLOGY is different.
I.E, LEAVES, ROOTS, STEMS
Consider other factors in a terrestrial environment that
impinge on what it means to be a plant vs. an animal
gravity, water.
Plants can fall over in the wind.
Significance?
Water supply not constant.
Significance?
Again, plants are anchored to the substratum.
They don’t pursue prey, or water.
They don’t LOCOMOTE. They don’t move, in the way animals move.
Plants exhibit INDETERMINATE GROWTH.
Like the battery bunny, they keep going, and going, and
going.....
How does that differ from animals?
Plants regenerate much better than animals.
They’re TOTIPOTENT.
What does that mean viz. anatomy, physiology, etc? What
about ‘practical’ implications, e.g. for propagation?
Look up the word.
To be continued...