Scioly.org

For probability with punnett squares, is it usually better to express the answer as a fraction or a percent?

I think it's a fraction, but I'm using ratio form (1:2:1, for example). Also, does anyone now how much we have to go into detail for mutations and genetic disorders? I'm doing heredity B btw.

Are any of you going to the Falls Invitationals? Are the Texas rules the same as the other rules? I went online and found a copy of the NC Designer Genes rules for 2012, but it says we can only bring in calculators, no reference materials...

If any of you have the rules for this year, can you please tell me what we need/can bring! Thanks in advance!

@ EAtBaBAna- standard seems to be use a ratio, unless it asks for something different. As far as mutations, our best guess (especially at B) is that you won't need too much depth for any of them. I'd know some common diseases (Trisomys, Monosomys, and some of the major inheritable diseases), what causes them (non-disjunction, mutation), and some of the major symptoms. Until we start actually taking tests, it's up in the air how much we need to know.

The rules seem to be a bit vague, and the actual genetics component seems to be at a level no more than that of a basic biology class. I'm suspecting that you might expect to see tests that require information more in-depth than those listed on the rule sheets.

What would happen if someone with a monosomy reproduces with a normal person? Would the offspring have developmental disability as a result of the missing genes? I'm just curious.

Cheesy Pie wrote:What would happen if someone with a monosomy reproduces with a normal person? Would the offspring have developmental disability as a result of the missing genes? I'm just curious.

It would depend.
Say the person has monosomy 18. When they do meiosis, producing the sperm/ovum, the chromosome pairs are split in half, creating two haploid cells (1 of each chromosome). However, this person only has one copy of chromosome 18. So half of the gametes will have a copy, and half won't. When this meets up with the ovum/sperm of the healthy individual, the copies will come together. So it all depends on if the cell that is fertilized/fertilizes is one with the copy or is one without. Theoretically, it's about a 50/50 shot, but this varies with age, environmental stuff, biological variables, whatever.
Note that meiosis is a little more complicated than that, but that will give you the basic idea of what's going on.
You can think of it as a dominant disease mutation- one chromosome with, one without, and the disease is present. Except instead of passing on a mutated gene, there is no genetic material passed on in half of the gametes.
Also, some monosomy diseases may result in infertility, so that could change results.

EAtBaNAna wrote:I think it's a fraction, but I'm using ratio form (1:2:1, for example). Also, does anyone now how much we have to go into detail for mutations and genetic disorders? I'm doing heredity B btw.

I agree with butter side up; here is a list of genetic disorders on wikipedia if you haven't seen it already (I would just look at the "most common" list): http://en.wikipedia.org/wiki/List_of_genetic_disorders

Any tips on studying for Heredity B? Or good books/websites?

PicturePerfect wrote:Any tips on studying for Heredity B? Or good books/websites?

Here is a good site.

http://www.dnaftb.org/#classical

sciencegeek999 wrote:Can Division B participants bring a note sheet?
Speaking of notes, I heard that someone in Designer Genes wrote notes all over their arms, but I have no clue what happened to them.

Yes, same resources allowed for both divisions.