The probability that their child will have sickle cell disease and be colorblind would be 1/8.
Both diseases are independent of each other.
So, considering the sickle cell alone: Let A be normal cell and S for sickle cell. A heterozygous man and woman would both be AS.
AS x AS
AA AS AS SS
Probability of their child having sickle cell = 1/4
Considering the color blindness alone, let a represents color blindness allele and A for normal eyes allele. A colorblind man would have [tex]X^aY[/tex] genotype while a woman with normal vision but with a colorblind father would be heterozygous with [tex]X^AX^a[/tex] genotype.
[tex]X^aY[/tex] x [tex]X^AX^a[/tex]
[tex]X^AX^a[/tex] [tex]X^aX^a[/tex] [tex]X^AY[/tex] [tex]X^aY[/tex]
Probability of their child being colorblind = 1/2
The probability of their child having sickle cell and being colorblind = probability of having sickle cell x Probability of colorblind
= 1/4 x 1/2
= 1/8
More on probability can be found here: https://brainly.com/question/851793