MathBench > Probability

Linked Genes and Recombination
Advanced Punnett

An easy Question

 

Assume both parents are ET/et, and the recombination frequency is 10%, so the chance of a gamete having the eT genotype is 5%.

What is the chance of a child having the eT/eT genotype? (You may or may not want to use the punnett square below).


     

 

  ET
45%
et
45%
Et
5%
eT
5%
ET
45%
ET/ET et/ET Et/ET eT/ET
et
45%
ET/et et/et Et/et eT/et
Et
5%
ET/Et et/Et Et/Et eT/Et
eT
5%
ET/eT et/eT ET/eT eT/eT

 

There is only one cell in this table with the genotype eT/eT, and you just calculated this occurs with a probability of 0.0025, or 0.25% of the time.

However, there are other ways for a child to get normal teeth and bug eyes: eT/et or et/eT. Are either of these represented in the punnett square?

So now for a harder question:

bug-eyedWhat is the total probability that a child will have normal teeth (TT or Tt) but insect eyes (ee)?