Dear Folks,
Reading Gini's posting about pepper cells reminded me about my attempts to
show cells in the lecture room. I received a number of suggestions from
the Plant Ed group, most of which I posted. I can report that I tried most
of them, and found they all came up lacking.
1. The interior of green pepper fruit seemed like the most promising,
since one doesn't even need a hand lens to see these bulging shapes on the
inside of the pepper. However, when I looked at these more closely using
the dissecting scope, followed by the compound scope, I discovered that
what appear to be cells are really places where the surface cell layer has
come away from the tissue below, and the spaced so created has filled with
water or juice. The layer that bulges out appears to my eye to be
comprised of small epidermal-type cells. So what looks a great deal like
large cells, are, I think, not truly cells at all. Having discovered that
I couldn't bring myself to fudge it with my non-majors.
2. Ring-porous twigs, such as oak. I tried this - went out and cut oak
twigs and looked at them with my 5X handlens. Could not see a vessel to
save my life. I took my research student with me and he could not see
anything either. Perhaps a higher mag lens would work, but not 5X.
3. Orange fruit segments. Didn't want to create a mess, plus there was
posted some concerns about whether they really represented single cells or
not.
4. Someone else suggested the wooden spoons you get with ice cream cups.
Got hold of some, looked with my hand lens - lots of streaks due to rays
and I can probably use them for discussing wood structure, but no visible
vessels or cells of any kind.
I gave up trying to have my students really see cells with just an
inexpensive hand lens. Since half my lenses walk out the room every time
we do something like this, I really can't afford a higher mag. So I'm
still searching and welcome any additional ideas that fit these criteria:
1. Must be visible with a 5X hand lens.
2. Must really be a cell.
Thanks,
Kathleen Archer
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