Country: United States
Date: Summer 2009
Are there any living organisms that developed without the use of an egg?
Yes, there are tons of them. Bacteria, fungi, plants, several invertebrates, the
list goes on and on. Reproduction can occur by fission (where a cell splits), budding
(a mini-cell grows from the parent), spore formation (a tight package of the stuff
needed for life) and other means too. Search on the net for 'asexual reproduction'
to read more about how organisms can reproduce without eggs.
And (I can't resist) the egg existed before the chicken.
Hope this helps,
Yes, there are plenty of living organisms that develop without the use
of an egg.
Eggs are part of sexual reproduction in animals. Organisms that utilize
asexual reproduction do not use eggs as part of their reproductive
cycle. An example is bacteria. A bacteria cell reproduces by copying
its genetic material and splitting its chromosomes and organelles into
two new cells. This process does not use eggs (or sperm).
Plants do not use eggs during reproduction either, although they do have
male and female counterparts to the sperm and egg that play similar
roles to those found in sexually reproducing animals.
When you consider how many organisms are plants and how many reproduce
asexually, really, very few organisms use eggs in development!
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Update: June 2012