[Catalist] Genetics question for Bio/ Human Bio Teachers

[Ray Forma]

Sarah,

the phrasing of the question is clearly unscientific; hence the correspondence. I, for one, cannot see that the question indicates that there is a possibility of a boy. Without clearer phrasing I can also interpret the question as being “what is the probability that they will produce an affected, rather that an unaffected, daughter?” Still confusing as this still leaves open the question of should I include the probability of the child’s sex. I therefore have to fall back on my years of experience, which is knowing that the person setting this question nearly always wants to know what is the overall probability of having a daughter, and that that daughter will have the characteristic. I feel sorry for the student who does not have that experience.

The lesson we should all take from this discussion is that clear, unambiguous language is an essential part of good science communication. Unfortunately, that’s not always the case. I shake my head when I read on my Australian Baked Beans “nett weight 425 g”, whereas the canned fruit from the less-developed South Africa states “nett mass 825 g” and “drained mass 480 g”.

As Ii dismount from my hobby-horse I also ask what’s wrong with our science syllabuses when well over 80% of our citizens believe that ‘the grid’ stores their solar ‘power' for them to use at nighttime.

> On 26 Oct 2017, at 14:09, Sarah Kelley <Sarah.Kelley at plc.wa.edu.au> wrote:
> 
> Hi Greg
>  
> The question states “what is the probability that they will produce an affected daughter?”, indicating that there is the possibility of having a boy, the girl is not the guaranteed gender of the unborn child so the probability would be25%.
>  
>  
> Sarah Kelley 
> Year 7 Learning Coordinator | Science Teacher
> Presbyterian Ladies' College | 14 McNeil Street, Peppermint Grove WA 6011
> Tel: +61 8 9460 6122 | http://www.plc.wa.edu.au

Regards,

Ray Forma
50 Harvest Road, North Fremantle WA 6159, Australia
Tel +61 (0) 428 596 938