Faster way to find genotypes without doing a punnet square

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
Posts: 1
Joined: Wed Sep 13, 2006 1:02 am

Faster way to find genotypes without doing a punnet square

Post by dimmere19 » Wed Sep 13, 2006 1:06 am

i have this simple question

the mating between Aa Bb Cc Dd x Aa Bb Cc Dd

Is there a faster way to answer this question without doing a punnet square

Posts: 3
Joined: Wed Sep 13, 2006 1:16 am

Post by Chaddycakes21 » Wed Sep 13, 2006 1:34 am

Lol, not really. Don't be so lazy. Most of us have had to do them.:)

User avatar
Inland Taipan
Inland Taipan
Posts: 2322
Joined: Sun Jan 02, 2005 12:44 pm
Location: Turkey

Post by Poison » Wed Sep 13, 2006 8:23 pm

You can find some mathematical proportions (some say they are the "proportion rules") for that, but they all come from punnet square, so I advise you to do it yourself and find those proportions yourself, then you can use them as a rule.

Here is a site for you to check yourself:

Good luck. :)
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.

User avatar
Inland Taipan
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN

Post by mith » Wed Sep 13, 2006 9:12 pm

A punnet square is a multiplication table
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;

King Cobra
King Cobra
Posts: 586
Joined: Sat Jul 30, 2005 7:16 pm
Location: holland

Post by sdekivit » Sat Sep 16, 2006 3:48 pm

if you search for some of my replies in genetics about genetics, you'll see another method in calculating genotype frequencies.

Assume the chance of every gamete is 1/2 to get passed on to the progeny.

Thus fro example: AaBbCc X AABBCc

--> for the left combination if you want to calculate the probability of passing abc than passing on a = 1/2, so are those of b and c --> combined probability = 1/2 * 1/2 * 1/2 = 1/8

--> right passes on ABc and thus the probability is 1 * 1 * 1/2 = 1/2

thus the genotype frequency of AaBbcc = 1/8 * 1/2 = 1/16.

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests