Question

A mother has one allele for color blindness and one allele for normal vision. What is the probability that her gamete will have the allele for color blindness ?

Answer 1

I am sure that the answer to your question would be 50/50 

Answer 2

The given case says that the lady is carrier for the colour blindness, which means she has one allele, which can cause colour blindness and one allele is normal.

The colour blindness is an X linked recessive trait. The females have 2 X chromosome, out of which 1 X chromosome she pass on to the gametes. As the lady have 1 chromosome for the trait and one is normal, there are 1 out of 2 chances, that the gamete would have the allele for colour blindness.

So, there are 50% chances that the gamete would have the allele for colour blindness.