How would you explain sexlinking to a 14 year old audience?!

[mom'sfolly]

For a five minute mini-lecture, going into too much detail would be silly.

I don't know what the whole lecture is on, but something simple like....

Sometimes chicks are bred for easy visual sexing. This is done using a sex-linked color trait. In chickens, as opposed to people, males have the double chromosome. A male with a double recessive color trait is bred with a female who has a single dominant color gene. This means that the female chicks will show the recessive trait inherited from the father because he is the only contributing a color gene, and the male chicks will show the dominant trait of the mother. One of the classic crosses for this is: (give example of red or black sex-linkage). This type of cross always produces a hybrid rather than purebred bird.

 

[sfw2]

I'm sorry, but we're talking about 14 year-olds. Avoid using the words "sex", "sexing" and "sexlink", unless you want the boys snickering and the girls giggling. Just my opinion.

 

[deerman]

Quote:
Except that albino in birds (or at least chickens) is not a sex-linked gene. It's a recessive allele (actually a couple of different ones) of recessive white.

My suggestion is to read the sex-link stickey at the top of the Breeds and Genetics section. The author is (or was; I think he retired) a high school biology teacher, and is very good at giving explanations.

never seen a albino chicken , but all albino birds i have raised have been sex link colors, and is also in people, so reason i used that, point is if any color is carry on the sex cheormosome. Can be used as a sexing at day old ,if mated sex-link male to non sexlink female. All you need to know whichare sex-link colors or type. Peafowl there are only 4 colors that are sex-link colors. Other thing like barring in chicken ,can be carry on the sex chormosomes.

 

[ivan3]

sfw2 wrote: I'm sorry, but we're talking about 14 year-olds. Avoid using the words "sex", "sexing" and "sexlink", unless you want the boys snickering and the girls giggling. Just my opinion.

Perfect for seguing from mom'sfolly outline to a hook into something that might be compelling enough to get a few snigglers doing some further reading, i.e., reproduction without breeding. "Yes, but sometimes no breeding 'sex' need occur in poultry for viable male offspring to be produced. No males required. This manner of `life finding a way' is termed parthenogenesis and reproductively viable male turkeys can be produced by hens that have never seen a male (tom) turkey. The definition of parthenogenesis:

http://ps.fass.org/misc/Poultry_Glossary.pdf

Describing this method of `reproduction' is beyond the scope of my presentation, however, if you are interested you'll have to slither into the den of the Timber Rattler":

http://www.salmonboa.com/images/Articles/Parthenogenesis in Snakes Schuett et al FAUNA 1998.pdf

*why parthenogenesis is a concern in commercial chickeneering: http://www.thepoultrysite.com/articles/837/parthenogenesis-embryonic-development-in-unfertilized-eggs-may-impact-normal-fertilization-and-embryonic-mortality

Supply the links and a few will be motivated...​

 

[booker81]

By 14, do they teach Mendel and the Punnett Square already in biology? That's probably the easiest visual, and it's something they may have already understood and grasped

 

[magicpigeon]

Quote:
Thankfully the school is single sex. And girls only

 

[welsummerchicks]

Or do like my teachers did. Make them snicker and then bean them with an eraser.

'Sex-linked traits hitch a ride on the chromosomes that determine gender'.

 

[Ridgerunner]

I'm assuming by North Sydney, you mean Australia. I'm not sure how the Australian school system is set up or what 14 year olds might know about genes and genetics. I'd hope they know that the offspring gets genes from both parents. If they don't already know that much, I don't think you have a chance. I'd talk to the teacher and try to find out how much they should already know. I'd sure hope a class of 14 year old girls would already have the basics for more reasons than your talk.

It is hard to keep it simple enough to keep their attention yet actually teach something.

I'd probably approach it that the hen gives certain genes to her sons but not her daughters. With chickens, certain genes are dominant over certain others and that some of these can show up at hatch. Like if silver is present, it gives yellow down even if gold is also present, but if only gold is present, with no silver, then the chick will have reddish down. Since hens only gives the silver gene to her sons and not to her daughters, then a silver hen and a gold rooster will produce chicks that you tell boy or girl based on down color when they hatch.

You might mention that with chickens, it is the hen that determines whether the chick will be male or female, depending on which genes she gives it. That might spike their interest. Welsummerchick's idea but maybe a bit simpler. Then tie this in with sex linked traits.

It is challenging. I wish you luck.

 

[pdsavage]

Why dont you do pics with it like take/get a pic of the roo and hen and show em what the off spring will look like as well...
Nothing better than pics to help explain what your talking about...