Biology Extra Credit Question... **ANSWER POSTED**

Discussion in 'Random Ramblings' started by Year of the Rooster, Nov 22, 2008.

  1. Year of the Rooster

    Year of the Rooster Sebright Savvy

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    Before I make a fuss here, this is only one question and it is only worth about 1-3 points of extra credit, but extra credit nonetheless. I am a big animal nerd and once I heard the question I immediately went through my encyclopedia in my brain [​IMG] If you could, please help me out. I have already tried searches on google, wikipedia, etc.

    We are starting a chapter about chromosomes and inherited traits. The question is:

    What animal's gender is NOT determined by chromosomes, but is determined right after birth?

    *Is not a Reptile.
    *Is a living organism
    *Is not a Hermaphrodite.

    Thanks for any help or suggestions everyone has. I will continue to search for the answer myself as well. [​IMG]
     
    Last edited: Nov 25, 2008
  2. chicken_boy_Kurt

    chicken_boy_Kurt Chillin' With My Peeps

    Mar 20, 2008
    I think it's birds.
     
  3. Year of the Rooster

    Year of the Rooster Sebright Savvy

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    Quote:But what kind of bird? [​IMG]


    Not a chicken of course [​IMG]
     
  4. redhen

    redhen Kiss My Grits... Premium Member

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    earthworm??[​IMG]..
     
  5. chicken_boy_Kurt

    chicken_boy_Kurt Chillin' With My Peeps

    Mar 20, 2008
    Quote:But what kind of bird? [​IMG]


    Not a chicken of course [​IMG]

    Oh a certain kind? I dunno.
     
  6. redhen

    redhen Kiss My Grits... Premium Member

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    so, is it a bird??
     
  7. Livinzoo

    Livinzoo Chillin' With My Peeps

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    Hmm I know some fish, Clownfish in particular, that don't have a sex until their harem needs it. They live in group. 1 male, 1 female and a group of neuter fish. When a male dies a neuter fish becomes male. If the female dies the male becomes female and a neuter fish becomes male. Once they are female they can not change again.

    Not sure if that is the answer your teacher is looking for though.
     
  8. Year of the Rooster

    Year of the Rooster Sebright Savvy

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    Quote:Oh! Sorry! I knew there was something else that it couldn't be and that is a hermaphrodite. [​IMG] Sorry, I already considered them, but once she said no hermaphrodites.... [​IMG] Thanks though...
     
  9. patandchickens

    patandchickens Flock Mistress

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    Honeybees? Sorta not really though? (It kind of depends what you mean "gender". Male bees i.e drones are haploid, from unfertilized eggs; genetically-female bees can be either workers or queens depending whether they're fed 'royal jelly' as larvae. If you consider 'worker' and 'queen' to be genders, then this fits the stipulation of the question.)

    Probably not what your teacher is looking for but the closest I can think of offhand.

    Good luck, make sure you eventually tell us what the answer really is [​IMG],

    Pat
     
  10. patandchickens

    patandchickens Flock Mistress

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    Oh wait, I did a quick google on "gender determination after hatching"...

    the answer is probably "some but not all fish".

    Sex Determination in Fish

    Sex determination and differentiation in fish is a common topic of discussion among aquarists. Just when in a fish’s life is its sex determined? At conception, when the sperm fertilizes the egg? At hatching? Or later in the fishes’ life, either as a factor of maturity, or as a consequence of environmental factors?
    T. J. Pandian and R. Koteeswaran of the School of Biological Sciences, Madurai Kamaraj University, Madurai, India, decided to address this question and then published their research results in the paper "Lability of sex differentiation in fish."
    The authors report that the process of sex determination and differentiation in fishes can be affected by chromosome manipulation during fertilization and the embryonic stages; by hormone levels during and just after hatching; and by temperature during the juvenile stages. In some fish gender can be altered by surgical and/or social changes during adulthood. It is known that fishes’ germ cells retain their bipotentiality to differentiate into male or female until sexual maturation, and that some species retain this flexibility even after sexual maturity.
    Research with a number of species indicated that manipulation of gender is only possible during very specific, limited time periods.
    Chromosomal manipulation – during insemination of the egg and early cleavages – is limited to a few seconds and minutes during and immediately after fertilization, and can result in a hatch of all females, all males, or complete sterility.
    Hormonal manipulation is restricted to a few minutes just before or after hatching (using the immersion technique) or to a few days after hatching for ornamental fish. In food fishes (such as carp and salmon) this may be extended to a few months, when using dietary administration of hormones.
    Thermal manipulation may be the simplest method for gender control in fish, although this has been shown to work only in the juvenile stages. This area has seen only limited research, results seem to indicate that lower temperatures result in females and higher temperatures result in males, with sex determination triggered by thermal control of certain enzymes.
    Although sex manipulation in fish has been widely practiced in many commercially important species for some time, there is evidence that it may result in stunted growth, sterility, and other undesirable effects. It should be noted that no one species has been thoroughly studied using all the potential methods of gender manipulation.
    Reference: Pandian, T.J., and R. Koteeswaran. "Lability of sex differentiation in fish." http://tejas.serc.iisc.ernet.
    -- G.C.K.A. Newsletter, September 2003

    from http://www.cincikillies.org/Archive_Breed_1-5.htm#Some%20Views%20On%20...%20Skewed%20Sex%20Ratios%20in%20Killifish

    Hope
    this helps,

    Pat​
     

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