|
Professor Niko Tinbergen, Oxford's first
professor of animal behaviour - friend and mentor, taught
my colleagues and I that every Herring Gull is different and
recognisable by both his own kind and by students of behaviour.
Ciliates (Paramecium) in yeast
Photograph by Peter Parks
The same goes for single celled animals, protozoa,
like the ciliate Paramecium caudatum. Swarms a million strong
appear to contain identical individuals. They are not. Every
one is different and recognisable. Everyone is a complex machine
of incredible complexity and few academic biologists know
it. Paramecium has within its single cell of living tissue
a digestive system almost as complex as our own and it can
be elegantly demonstrated.
Ciliate (Paramecium) in yeast
Photograph by Peter Parks
Equipped with a short, blind ended gullet,
the cell wafts cellular and particulate material into this
shallow funnel with its "buccal" cilia. At the inner end of
the gullet is a tiny window of naked cytoplasm which, in amoeboid
fashion, engulfs organic nutritional material within a food
vacuole. The process is rapid and amongst abundant food, like
yeast cells which it appears to relish, it may engulf up to
a hundred or more cells at one "sitting". If these cells are
previously stained with a universal pH indicator like "Congo
Red" it is possible, elegantly to demonstrate that these food
vacuoles are first subjected to acid digestion and then to
alkali digestion. Acid conditions maintain the dye as red
or orange. Alkali turns it first brown, then Prussian blue.
We humans employ the same technique in our own acid stomach
and alkali intestinal tracts. Furthermore, Paramecium can
extract, in crystalline form, bright refractive storage products
for later metabolic use. We store similar reserves as fat.
To use today's language……a smart cell!
This article was written
by Peter Parks
If
you have an article of general interest that you would like
considered for the article of the month then we would love
to hear from you. If you are also able to supply images then
we can include those as well. You can email us at iq3d@imagequest3d.com
|
