PROBABILITIES OF GENETIC TRAITS

Exercises Involving Dice

When two dice are thrown, find the probability of rolling:

1. two five's 2. a five then a two

3. a five and a two 4. no fours

5. all even number 6. an odd and an even

7. two sevens 8. two values each less than five

9. two values with a sum of

a) eleven b) ten

Checking for Understanding

Find a baby's probability of inheriting ridged fingernails if the genetic make-up of the parents is as follows:

1. father = Rr, and mother = rr

Solution: Since the mother does not have an "R" allele, the baby can't inherit "RR", so . The possible inheritance for the baby is "Rr" (mother's first r), "Rr" (mother's second r), "rr", and "rr" again.

2. father = RR, and mother = Rr

3. father = rr, and mother = RR

4. father = rr, and mother = Rr

0

Genetics Probability Exercises

Given the genetic make-up of the parents, determine the indicated probabilities.

1. If the make-up of the father = EeGg, and the mother = EEGg, then find the probability that the child will be:

a. EEGg b. EEgg c. Eegg

d. EeGG e. EeGg f. EEGG

2. If the make-up of the father = Ttqq, and the mother = TtQQ, then find the probability that the child will be:

a. TtQq b. Ttqq c. ttQq

0

d. TTQq e. have the f. have both dominant Q-trait dominant traits

1

3. If the make-up of the father = RrHh, and the mother = RrHh, then find the probability that the child will be:

a. RRHH b. RRHh c. Rrhh

d. RrHH e. RrHh f. RRhh

g. rrHH h. rrHh i. rrhh

j. have the dominant k. have both traits

R-trait dominant

4. If the make-up of the father = Ddtt, and the mother = DdTt, then find the probability that the child will be:

a. the same as the father b. the same as the mother c. Ddtt

d. all dominant traits e. dominant T-trait and f. all traits

recessive d-trait recessive

5. If the make-up of the father = AaBb, and the mother = AaBb, then find the probability that the child will have:

a. all recessive alleles b. all recessive traits c. AaBb

d. all dominant alleles e. all dominant traits f. Aabb

g. dominant A-trait h. recessive a-trait i. aaBb

j. dominant A-trait & k. recessive a-trait &

recessive b-trait dominant B-trait

6. If the make-up of the father = EeFfGg, and the mother = eeFFGg, then find the probability that the child will be:

a. EEFFGG b. eeffgg c. EeFfGg

0 0

d. only the E-trait e. only the e-trait f. all 3 traits

is dominant is recessive recessive

0

g. 3 dominant traits h.only E and G dominant i. only e and g

recessive