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Author Topic: Do All Animals Use Chromosones To Determine Gender ?  (Read 4020 times)

Offline neilep

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Dear Genderologists,

As a sheepy I of course have a gender.....genders are my all time favourite DNA way of determining the sex of someone....which is nice !


Look, here's some chromosomes:



Some X & Y Chromosomes Determining
The Gender Of Something Yesterday







Nice eh ?

Are there any instances in the rest of the animal kingdom that do NOT rely on chromosomes for gender orientation ?


As a firm believer in empirical study I snuk into my neighbours house at 3am this morning and asked because he has family who live in Cromer Road ie: the ' Cromer Zone ' but all he did was remain unconscious under the sedative he allowed me to force him to take...so..no luck there !

whajafink ?

Is it all about X & Y  ?

hugs & shmishes


mwah mwah mwah !!!




Neil
Chromosome Enquirer
xxxxxxxxxxxxxxxxxxxx








 

Offline Variola

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Do All Animals Use Chromosones To Determine Gender ?
« Reply #1 on: 11/08/2009 17:36:32 »
Here you go sheepy..

Quote
Not all animals possess the "traditional" XY chromosomal sex determination
mechanisms. Mammals including humans, Drosophila and many other species have
an X-Y mechanism that determines sex at fertilization. The male is the
heterogametic sex, containing an X chromosome and a Y chromosome. The female
is the homogametic sex carrying two X chromosomes. However, the mechanism
that determines maleness may vary among these animals. For example, in
mammals it is the presence of the Y chromosome, but in Drosophila, maleness
is not determined by the presence of Y but by the ratio of X chromosomes
to autosomes.

Other animals like grasshoppers, crickets, roaches and some other insects
have an X-O sex detrmination mechanism.Like the X-Y system, the male is the
heterogametic sex because males have two types of gametes: X and O (absence
of sex chromosome). Females have two X chromosomes.
           
A third sex determination mechanism is Z-W found in birds, some fish and
some insects such as butterflies and moths.The female is the heterogametic
sex; males are ZZ while females are possess two different sex chromosomes,
ZW.

Finally, some animals exhibit haplo-diploidy. Some species of bees and ants
have no sex chromosomes at all, yet sex determination has a chromosomal
basis.Females develop from fertilized eggs and are diploid (have two copies of
each chromosome).Males develop from unfertilized eggs (parthenogenetically) and
are haploid (have only one copy of each chromosome).

[url]http://www.madsci.org/posts/archives/2001-02/983580120.Ge.r.html/url]


Pretty cool huh??  [O8)]


 

Offline neilep

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Do All Animals Use Chromosones To Determine Gender ?
« Reply #2 on: 11/08/2009 17:42:40 »
Here you go sheepy..

Quote
Not all animals possess the "traditional" XY chromosomal sex determination
mechanisms. Mammals including humans, Drosophila and many other species have
an X-Y mechanism that determines sex at fertilization. The male is the
heterogametic sex, containing an X chromosome and a Y chromosome. The female
is the homogametic sex carrying two X chromosomes. However, the mechanism
that determines maleness may vary among these animals. For example, in
mammals it is the presence of the Y chromosome, but in Drosophila, maleness
is not determined by the presence of Y but by the ratio of X chromosomes
to autosomes.

Other animals like grasshoppers, crickets, roaches and some other insects
have an X-O sex detrmination mechanism.Like the X-Y system, the male is the
heterogametic sex because males have two types of gametes: X and O (absence
of sex chromosome). Females have two X chromosomes.
          
A third sex determination mechanism is Z-W found in birds, some fish and
some insects such as butterflies and moths.The female is the heterogametic
sex; males are ZZ while females are possess two different sex chromosomes,
ZW.

Finally, some animals exhibit haplo-diploidy. Some species of bees and ants
have no sex chromosomes at all, yet sex determination has a chromosomal
basis.Females develop from fertilized eggs and are diploid (have two copies of
each chromosome).Males develop from unfertilized eggs (parthenogenetically) and
are haploid (have only one copy of each chromosome).

[url]http://www.madsci.org/posts/archives/2001-02/983580120.Ge.r.html/url]


Pretty cool huh??  [O8)]





Wooo !!

That is kewl !!..Thank ewe very much Varioioioioioioioioioioila...sorry..I broke into spontaneous yodeling !!
 

Offline RD

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Do All Animals Use Chromosones To Determine Gender ?
« Reply #3 on: 11/08/2009 18:35:19 »
What about crocs ...
   
Quote
Rising global temperatures could disrupt gender balance among reptile populations, a crocodile researcher has warned.

According to Dr Alison Leslie of South Africa's University of Stellenbosch, crocodiles are likely to be affected by warmer waters
 as their gender is not determined by genetics but is instead due to embryo temperature during incubation.
http://www.inthenews.co.uk/news/news/science/crocodile-gender-affected-by-global-warming-$459349.htm

« Last Edit: 11/08/2009 18:36:53 by RD »
 

Offline neilep

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Do All Animals Use Chromosones To Determine Gender ?
« Reply #4 on: 11/08/2009 18:37:54 »
What about crocs ...
   
Quote
Rising global temperatures could disrupt gender balance among reptile populations, a crocodile researcher has warned.

According to Dr Alison Leslie of South Africa's University of Stellenbosch, crocodiles are likely to be affected by warmer waters as their gender is not determined by genetics but is instead due to embryo temperature during incubation.
http://www.inthenews.co.uk/news/news/science/crocodile-gender-affected-by-global-warming-$459349.htm


Ah ha !!...fascinating stuff !!..yes yes,,,the temperature thingy !!.Thanks RD....Yes, I guess this could cause a problem with temperature orientated gender determined species............Perhaps they have an evolutionary trick in their genes !
 

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Do All Animals Use Chromosones To Determine Gender ?
« Reply #4 on: 11/08/2009 18:37:54 »

 

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