Punnett Square LIES!

[wired202808]

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lol sorry for the header but in one Bio problem it asks for "what is the chance that a color blind carrier (woman) and a normal male have a boy that is normal?

The answer is 25% for some reason they multiple the probability of having a boy TIMES the probability of having colorblindness.

Why would you do this? Im confused lol

 

[rccostner]

lol sorry for the header but in one Bio problem it asks for "what is the chance that a color blind carrier (woman) and a normal male have a boy that is normal?

The answer is 25% for some reason they multiple the probability of having a boy TIMES the probability of having colorblindness.

Why would you do this? Im confused lol

the chance of having a boy with each pregnancy is 50%. the chance of a girl is also 50%. since being colorblind is an X-linked trait the a boy will only inherit an X from his mother and a Y from his father. The mother is a carrier, which means she has a 50% chance at donating a normal X and a 50% chance of donating the X with the colorblind gene. You have to multiply the two probabilities together to find that they have a 25% chance at a colorblind boy, 25% chance at a normal boy, 25% chance at a normal girl, and a 25% chance at a colorblind carrier girl.

 

[wired202808]

the chance of having a boy with each pregnancy is 50%. the chance of a girl is also 50%. since being colorblind is an X-linked trait the a boy will only inherit an X from his mother and a Y from his father. The mother is a carrier, which means she has a 50% chance at donating a normal X and a 50% chance of donating the X with the colorblind gene. You have to multiply the two probabilities together to find that they have a 25% chance at a colorblind boy, 25% chance at a normal boy, 25% chance at a normal girl, and a 25% chance at a colorblind carrier girl.

thanks mate! i realized this after i wrote it up!

 

[rccostner]

thanks mate! i realized this after i wrote it up!

for what it's worth, the genetics on my DAT wasn't any more difficult than this question. i'm sure other people had some more challenging questions, but every question i had was very basic and they told me the inheritance pattern. good luck.

 

[wired202808]

for what it's worth, the genetics on my DAT wasn't any more difficult than this question. i'm sure other people had some more challenging questions, but every question i had was very basic and they told me the inheritance pattern. good luck.

thanks thats good to know. i confused the male and the female in terms of carriers and looked at one X carrier and one Y and forget that a male only has 1 X and is therefore color blind with the one Xc