Solutions For An Introduction to Genetic Analysis Chapter 3 Problem 45P

Jar 2: the probability of blue and white marbles is calculated separately.

Jar 3: the probability of green and white marbles is calculated separately.

1. The probability of selecting a red marble, a blue marble and a green marble can be calculated in the following way:

2. The probability of selecting a white marble from all the three jars can be calculated in the following way:

3. The probability of selecting a red marble from the first jar, a green marble from the third jar and a white marble from the second jar can be calculated in the following way:

4. The probability of selecting a red marble from the first jar, a white marble from both the second and third jars can be calculated in the following way:

5. The probability of selecting one color marble and the other two white marbles needs to be calculated in a different way. The thee combinations for the three jars are:

• Red, white, white:

• White, blue, white:

• White, white, green:

Now all the three probabilities are added to get the final number as 0.4162.

6. The probability of getting at least one white can be calculated in this way:

b) The selfing of a heterozygote R/r will give a cross of R/r x R/r. the probability of red plant is 3/4 and the probability of a white plant is 1/4. Since we need only one white plant, we need to calculate the probability of a red plant in n number of trials.

The probability of all red progeny is (3/4)ⁿ

The probability of failure cannot be greater than 5% or 0.05.

Hence, the minimum number of seeds which need to be grown to be at least 95% sure of obtaining a white plant would be 10.6 or ~11 seeds.

c) The probability of an injected fertilized egg implanting successfully is 20%. The probability of failure is 80% or 0.8 for each egg.

When five eggs are injected simultaneously, the probability of failure:

The probability of at least one success is:

The probability that she will become pregnant is 0.67 or 67%.