Q: If you flip a fair coin three times, what is the probability of getting exactly two heads?

$$P = 3 \times (\frac{1}{2})^3$ = 0.375$$

Question 1

Which of the following best describes the product rule in probability theory as applied to Mendelian genetics?

Accepted Answer

It is used to calculate the probability of independent events occurring together by multiplying their individual probabilities.

Question 2

A couple has six children. What is the probability that exactly five will be girls and one will be a boy? Use the binomial probability formula.

Accepted Answer

$$P = \frac{6!}{5!1!} (\frac{1}{2})^5$ (\frac{1}{2})^1$ = \frac{6}{64} = 0.09375$$

Question 3

In a cross between two heterozygous yellow-seeded pea plants (Gg x Gg), what is the probability that a yellow-seeded offspring is heterozygous?

Accepted Answer

$$\frac{2}{3}$$

Question 4

Which equation correctly represents the sum rule for mutually exclusive events?

Accepted Answer

$$P = P_1$ + P_2$

Question 5

If you flip a fair coin three times, what is the probability of getting exactly two heads?

Accepted Answer

$$P = 3 	imes (\frac{1}{2})^3$ = 0.375$$

Question 6

Which of the following is the correct formula for binomial probability?

Accepted Answer

$$P = n!/(s!t!) p^s q^t$$

Question 7

A pod contains 8 seeds from a Gg x Gg cross. What is the probability that exactly 4 seeds are green (gg)?

Accepted Answer

$$P = \frac{8!}{4!4!} (\frac{1}{4})^4$ (\frac{3}{4})^4$

Question 8

Which of the following statements about the normal distribution is correct in the context of Mendelian inheritance?

Accepted Answer

A result is considered statistically significant if it falls more than about $$2\sigma$$ away from the mean ($$\mu).$$

Question 9

Given the chi-square formula $$\$$chi^2$$ = \sum \frac{(O-E)^2$}{E}$$, what does a high chi-square value indicate about your observed and expected data?

Accepted Answer

There is a significant difference between observed and expected data, possibly indicating a violation of the null hypothesis.

Question 10

In a chi-square test with 3 outcome classes, what are the degrees of freedom (df)?

Accepted Answer

$$df = 2$$

Question 11

A geneticist observes 5474 round and 1850 wrinkled seeds in an F2 generation, where 7324 seeds were expected to segregate 3:1. What is the expected number of round seeds?

Accepted Answer

$$5493$$

Question 12

If the observed and expected values in a chi-square test are very close, what can you conclude about the null hypothesis?

Accepted Answer

You fail to reject the null hypothesis; the data fits the expected ratio.

Question 13

Which probability rule would you use to determine the likelihood of getting either a boy or a girl in a single birth?

Accepted Answer

Sum rule

Question 14

A cross produces 4 seeds per pod, with each seed having a 75% chance of being tall. What is the probability of getting exactly 3 tall and 1 short seed in a pod?

Accepted Answer

$$P = \frac{4!}{3!1!} (\frac{3}{4})^3$ (\frac{1}{4})^1$ = 0.42$$

Question 15

Which of the following is NOT a requirement for using the chi-square test in genetics?

Accepted Answer

The sample size must be less than 10.

Question 16

If you observe a p-value less than 0.05 in a chi-square test, what does this indicate?

Accepted Answer

There is a statistically significant difference between observed and expected values.

Question 17

Which of the following best describes conditional probability in genetics?

Accepted Answer

It is used to calculate the probability of an event given that another event has already occurred.

Question 18

In a binomial distribution with $$n=10$$ and $$p=0.5$$, what is the expected number of successes?

Accepted Answer

$$5$$

Question 19

Which of the following is a real-world application of the binomial probability formula in genetics?

Accepted Answer

Predicting the probability of a family with 4 children having exactly 2 boys and 2 girls.

Probability Theory and Statistical Analysis in Mendelian Genetics

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