Genetics Math For Those Who Took The Mcat

[CurryPower]

cURIOUS ABOUT GENETICS MATH....

Do they ask tough probability questions involving a lot of different events occurring or is it basic?

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[engineeredout]

Can't imagine they would start diverging into chi-squared, even though they should cause statistics is awesome.

 

[Isoprop]

you should know the addition rule and the multiplicity rule for genetics problems. they might throw a pedigree at you and ask what's the probability the the offspring between two people will be a carrier of some rare recessive genetic trait.

there is limited to no statistics on the mcat though it is listed in the "syllabus."

 

[mterp45]

cURIOUS ABOUT GENETICS MATH....

Do they ask tough probability questions involving a lot of different events occurring or is it basic?

All the math you need to know are the mandelian ratios, which are easily memorized :

AA + AA = 100% AA
Aa + Aa = 25% AA, 50 %Aa, and 25% aa
Aa + aa = 50% AA, and 50% aa
Aa+ AA = 50% AA, and 50% Aa

memorize this and you will be able to solve all probability questions on the MCAT.

 

[J ROD]

All the math you need to know are the mandelian ratios, which are easily memorized :

AA + AA = 100% AA
Aa + Aa = 25% AA, 50 %Aa, and 25% aa
Aa + aa = 50% AA, and 50% aa
Aa+ AA = 50% AA, and 50% aa

memorize this and you will be able to solve all probability questions on the MCAT.

Not be an @ss! But, the last one: Aa + AA should be 50% AA and 50% Aa

 

[mterp45]

Not be an @ss! But, the last one: Aa + AA should be 50% AA and 50% Aa

No that doesn't make you "@ss" at all, I am thankful you caught that . I just edited it. I wouldn't want to be the reason someone gets a 9 as opposed to a 10. Thanks.

 

[utjsm08]

Know these two rules of probability:

1) The probability of two independent events occuring together is equal to the product of the probability of each event occuring alone: so the probability of A & B happening together is the probability of A happening alone * probability of B happening alone

2) The probabilty of either event A OR B happening is the sum of the probabilities of A & B minus the product of A&B. A OR B happening = (A+B) - (A*B)

This along with the ratios mentioned above should get you through most genetics math they can throw at you.

 

[ldnk]

Everything starts and ends with the simple probabilities shown above. Don't bother with punnet squares, don't bother with complex numbers. Simple probabilities and know your basis rations: 1:2:1; 9:3:3:1 and then realize that everything is just a variation of those two ratios.

 

[unsung]

All the math you need to know are the mandelian ratios, which are easily memorized :

AA + AA = 100% AA
Aa + Aa = 25% AA, 50 %Aa, and 25% aa
Aa + aa = 50% AA, and 50% aa
Aa+ AA = 50% AA, and 50% Aa

memorize this and you will be able to solve all probability questions on the MCAT.

Dang, am I the only one that still draws punnet squares? 😛

 

[Libtech]

Dang, am I the only one that still draws punnet squares? 😛

Heh, you are NOT the only one! I drew one for a discrete on my real test just to check the math. I definitely did not want to risk a point especially when I finished Bio with 20 minutes left .