Page 14 of 16
Re: Heredity B/Designer Genes C
Posted: April 24th, 2013, 4:49 pm
by MacBookMinus
Anybody in Division B think that we need to know about PCR, or that one thing I've seen in Div. C tests where you use lines to figure out who the father was? Sorry for being really unspecific I can't put it into words.
Re: Heredity B/Designer Genes C
Posted: April 24th, 2013, 4:50 pm
by MacBookMinus
How do you become a mod?
Edit: it's ridiculous how tech impaired I am. I edited my post like 6 times before I got it right.
Re: Heredity B/Designer Genes C
Posted: April 24th, 2013, 9:12 pm
by mnstrviola
honeybunchesofoats wrote:Someone help me with Baye's theorem for conditional probabilities?
So according to my packet, the equation is P(B|A) = P(A and B)/P(A).
Suppose a woman is carrying one X chromosome with the gene for a particular type of colorblindness. She marries a man who does not have this gene on his X chromosome. What is the probability that her first child will carry the X chromosome with the gene associated with color blindness?
I'm not sure how to take that information and put it into the equation. :/
I think this means
The probability of A given B = The probability of both occuring, divided by the probability of A
which means
The probability of A, assuming B is correct = The probability of both A and B happening, divided by the probability of A happening
I'm not sure how it fits for your problem, but I can give it a shot
P(B|A) = P(A and B)/P(A).
B= child inherits the colorblindness gene from her parents
A= given her carrier mom marries a healthy dad
This may not be the right setup, but you can reason it out without using that probability thing.
If the child is male, he has a 50% chance of inheriting the X chromosome with colorblindness. His dad's chromosome doesn't really matter.
If the child is female, she has a 50% chance of inheriting the X chromosome with colorblindness. Her dad's chromosome doesn't really matter.
(.5*.5)+(.5*.5)=.5
There is a 50% chance the child will inherit the gene for colorblindness.
Hopefully this is what you're looking for

Re: Heredity B/Designer Genes C
Posted: April 27th, 2013, 8:32 am
by honeybunchesofoats
Thanks ^^ I still don't understand it, but I guess I could just reason it out then (:
Re: Heredity B/Designer Genes C
Posted: April 29th, 2013, 10:42 am
by Beastybob12345
Hi guys, I'm thinking about doing Heredity for next year. What do you do in it? And is it difficult?
Thanks

Re: Heredity B/Designer Genes C
Posted: April 30th, 2013, 8:13 pm
by ScienceOlympian
Beastybob12345 wrote:Hi guys, I'm thinking about doing Heredity for next year. What do you do in it? And is it difficult?
Thanks

It is a lot of probability, and genetic disorder. And enzymes! DNA Polymerase!!!
Like all events, Heredity can be difficult. Start out with the easy topics. Then learn to do Dihybrid crosses, then Trihybrid. Learn about blood types. I recommend doing a practice test that has a baby question: Three babies were mixed up in the hospital and they need to get to their real parents! Then do a blood type Punnett square.
Heredity is very fun!
Re: Heredity B/Designer Genes C
Posted: May 1st, 2013, 8:27 am
by Beastybob12345
ScienceOlympian wrote:Beastybob12345 wrote:Hi guys, I'm thinking about doing Heredity for next year. What do you do in it? And is it difficult?
Thanks

It is a lot of probability, and genetic disorder. And enzymes! DNA Polymerase!!!
Like all events, Heredity can be difficult. Start out with the easy topics. Then learn to do Dihybrid crosses, then Trihybrid. Learn about blood types. I recommend doing a practice test that has a baby question: Three babies were mixed up in the hospital and they need to get to their real parents! Then do a blood type Punnett square.
Heredity is very fun!
Sounds complicated but fun!!

And we're learning it in 7th grade aren't we? That would be good for me.

Re: Heredity B/Designer Genes C
Posted: May 1st, 2013, 5:25 pm
by ScienceOlympian
Beastybob12345 wrote:ScienceOlympian wrote:Beastybob12345 wrote:Hi guys, I'm thinking about doing Heredity for next year. What do you do in it? And is it difficult?
Thanks

It is a lot of probability, and genetic disorder. And enzymes! DNA Polymerase!!!
Like all events, Heredity can be difficult. Start out with the easy topics. Then learn to do Dihybrid crosses, then Trihybrid. Learn about blood types. I recommend doing a practice test that has a baby question: Three babies were mixed up in the hospital and they need to get to their real parents! Then do a blood type Punnett square.
Heredity is very fun!
Sounds complicated but fun!!

And we're learning it in 7th grade aren't we? That would be good for me.

Yep but it is basic. The most complicated thing i learned was Dihybrid crosses, and we only did one Dihybrid cross. You would have to practice, practice, practice it! Take some Designer Genes tests from the Test Exchange. And karyotypes, pedigrees are important.
Re: Heredity B/Designer Genes C
Posted: May 2nd, 2013, 5:41 pm
by PicturePerfect
@BeastyBob:
Heredity is probably my favorite event. Some questions are harder than others, but it's really fun. And yes, 7th grade Life Science does teach Heredity

Re: Heredity B/Designer Genes C
Posted: May 2nd, 2013, 6:20 pm
by ScienceOlympian
PicturePerfect wrote:@BeastyBob:
Heredity is probably my favorite event. Some questions are harder than others, but it's really fun. And yes, 7th grade Life Science does teach Heredity

@PicturePerfect
My favorite event is a close tie between Shock Value and Heredity, so it is technically my favorite event. So me too!
@Beastybob12345
I barely studied for my Regionals test for Heredity, since I already had a unit on Heredity in Science, but the test was extremely hard... Even harder than the State Test. But I managed to get 3rd, mysteriously. So don't rely on your Science class TOO much.