Question

Scientists have found that being obsessed with taking selfies is actually due to a recessive "selfies" gene.

Suppose two "selfies" carriers produce a child. (Write probabilities as unsimplified fractions):

a. Draw a Punnet square on your paper representing the outcomes in this situation (Use S for selfie gene and N for no selfie gene)

b. What is the probability the child will be obsessed with taking selfies?

c. What is the probability the child will be a "selfies" carrier?

d. What is the probability the child will neither have the disease nor be a carrier?

Answer 1

a. Punnett square:

| S | N |
------|----------|---------|
S | SS | SN |
------|----------|---------|
N | NS | NN |

b. The probability that the child will be obsessed with taking selfies is 1/4 or 25%. This corresponds to the outcome SS in the Punnett square.

c. The probability that the child will be a "selfies" carrier is 2/4 or 50%. This includes the outcomes SS and SN in the Punnett square.

d. The probability that the child will neither have the "selfies" gene nor be a carrier is 1/4 or 25%. This corresponds to the outcome NN in the Punnett square.