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Date: | Sun, 11 Jan 1998 22:27:27 -0500 |
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Hello!
Here is a better one, this Brit on line is neat:
Referring to inverts;
Although asexual reproduction occurs in many invertebrate species, most
reproduce sexually. The basic unit of sexual reproduction is a gamete
(sperm or egg), produced by specialized tissues or organs called
gonads.
Sexual reproduction does not necessarily imply copulation or even a
union of gametes. As might be expected of such a large and diverse
group as the invertebrates, many variations have evolved to ensure
survival of species. In many lower invertebrates, gonads are temporary
organs; in higher forms, however, they are permanent. Some
invertebrates have coexistent female and male gonads; in others the same
gonad produces both sperm and eggs. Animals in which both sperm and
eggs are produced by the same individual (hermaphroditism) are termed
monoecious. In dioecious species, the sexes are separate. Generally,
the male gonads ripen first in hermaphroditic animals (protandry); this
tends
to ensure cross-fertilization. Self-fertilization is normal, however, in
many
species, and some species undergo sex reversal. (see also Index:
dioecism)
--
Later,
Emilio Jorge Power
Please visit;
"The Liguus Home Page"
http://pw1.netcom.com/~ejpower/lighompage.html
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