Sickle cell anemia is a genetic disease that occurs only if a child inherits two recessive genes. Each child receives one gene from the father and one from the mother. A person can be characterized as follows: The person can have:

(a) two dominant genes (cannot transmit the disease to a child),

(b) one domi- nant and one recessive gene (has the trait and is therefore a carrier who can pass on the disease to a child, but does not have the disease), or

(c) has both recessive genes (in which case the person has the disease and is a carrier of the disease). For each parent there is a 50-50 chance that the child will inher- it either the dominant or the recessive gene. Calculate the probability of the child having the disease if:

a. Both parents are carriers

b. One parent is a carrier and the other has two dominant genes

c. One parent is a carrier and the other has the disease Calculate the probability that the child will be a carrier if:

d. Both parents are carriers

e. One parent is a carrier and the other has the disease

f. One parent is a carrier and the other has two dominant genes