Koning at ECSUC.CTSTATEU.EDU
Tue Dec 10 13:01:45 EST 1996
At 6:32 AM 12/9/96 +0000, kjohn95416 at aol.com wrote:
>I was wondering if anyone knows if a Hermaphroditic plant that pollenates
>itself would create exact copies of itself and its offspring will also be
>Any help on this matter would be greatly appreciated. E-mail me or simply
>post a message for me.
The key word in your post is "pollinates" because
if the plant indeed makes pollen and the pollen
makes sperm, and the sperm unites with an egg in
the ovule, then indeed there should be some natural
variations in the offspring. To make pollen and
embryo sac (egg), the cells must go through meiosis.
That process provides new combinations of chromosomes
(independent assortment), and indeed sections of
chromosomes (cross-over) that never co-existed
before. Indeed the offspring should have some
HOWEVER...some species that DO inbreed like this
on a regular basis have lost much of their natural
variation over time. Thus they are homozygous
(AA or aa but not Aa) in many/most/all genes and
so any recombinations have NO NET EFFECT and all
offspring are thus identical.
SO...it depends on the level of genetic diversity
(heterozygosity) of ONE parent. If it has a high
level of heterozygosity (Aa Bb Cc...etc.), then
the offspring will be more diverse.
A fun plant to think about is hybiscus (there are
many species). The flower opens and is animal-
pollinated under normal circumstances. The flower
is well-adapted for this. However, in many species,
if you keep all animals away so that the flower is
NOT pollinated during the morning hours, the stigmas
arch backwards and eventually touch their own anthers
and self-pollinate! This way the plant is "facultative"
and "swings both ways?!" Wierd. Cool. Whatever!
There ARE plants that are obligate out-crossers and still
others that are obligate self-crossers. Some don't even
need a male contribution! Plants cover the spectrum of
sexual types quite comprehensively. It's part of what
makes them interesting to me.
Ross Koning | Koning at ecsu.ctstateu.edu
Biology Department | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | Phone: 860-465-5327
Willimantic, CT 06226 USA | Fax: 860-465-5213
Plant Physiology is Phun!
/\|___/\ //\______COOH NH-CH2-CH=C-CH2OH \/OH
| | | | | | || //\___ \CH3 /\|/\\/\\COOH
\/ \/|\/| \\/ \ / N || N | |
/\ | |__|= NH | || || //\//\
| COOH \\ /\ / O
COOH H2C=CH2 N NH
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