Q: If a family has three children, what is the probability that exactly two of them are boys? (Assume probability of boy or girl is 0.5 each)

$$3 \times (0.5)^2$ \times (0.5)^1$ = 0.375$$

Q: If the observed values in a monohybrid cross are 5474 round and 1850 wrinkled seeds (total 7324), what are the expected values for round and wrinkled seeds according to Mendelian genetics?

Round: $$7324 \times \frac{3}{4} = 5493$$, Wrinkled: $$7324 \times \frac{1}{4} = 1831$$

Question 1

Which of the following best describes Mendel’s Law of Segregation?

Accepted Answer

Alleles for a gene separate during gamete formation, so each gamete receives only one allele.

Question 2

A plant with genotype Aa is crossed with a plant with genotype aa. What is the expected phenotypic ratio of the offspring if 'A' is dominant to 'a'?

Accepted Answer

1:1 (dominant:recessive)

Question 3

Which cross would you perform to determine if a dominant phenotype is homozygous or heterozygous?

Accepted Answer

A test cross with a homozygous recessive individual

Question 4

In a dihybrid cross between two heterozygotes (RrGg x RrGg), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 5

If a family has three children, what is the probability that exactly two of them are boys? (Assume probability of boy or girl is 0.5 each)

Accepted Answer

$$3 	imes (0.5)^2$ 	imes (0.5)^1$ = 0.375$$

Question 6

Which of the following is NOT a characteristic of autosomal dominant inheritance?

Accepted Answer

Two unaffected parents can have an affected child.

Question 7

A cross between two heterozygous pea plants (Gg x Gg) produces yellow and green seeds. What is the probability that a yellow-seeded offspring is heterozygous?

Accepted Answer

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

Question 8

Which probability rule would you use to calculate the chance of getting either a round or a wrinkled seed in a single cross?

Accepted Answer

Sum rule (addition rule)

Question 9

In a chi-square test, what does a P value greater than 0.05 indicate about your hypothesis?

Accepted Answer

There is no statistically significant difference between observed and expected results; hypothesis is accepted.

Question 10

How many different types of gametes can be produced by an individual with the genotype AaBbCc?

Accepted Answer

$$2^3 = 8$

Question 11

A pedigree shows a trait that skips generations and affects males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal recessive

Question 12

Which of the following best explains the molecular basis for Mendel’s observed morphological variation?

Accepted Answer

Differences in DNA sequence between alleles lead to differences in protein structure and function.

Question 13

If the observed values in a monohybrid cross are 5474 round and 1850 wrinkled seeds (total 7324), what are the expected values for round and wrinkled seeds according to Mendelian genetics?

Accepted Answer

Round: $$7324 	imes \frac{3}{4} = 5493$$, Wrinkled: $$7324 	imes \frac{1}{4} = 1831$$

Question 14

Which of the following is a key feature of autosomal recessive inheritance?

Accepted Answer

Affected individuals are often born to unaffected parents.

Question 15

A pure-breeding tall plant (AA) is crossed with a pure-breeding short plant (aa). What will be the genotype and phenotype of the F1 generation?

Accepted Answer

Genotype: Aa, Phenotype: all tall

Question 16

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

Accepted Answer

The probability of two independent events both occurring is the product of their individual probabilities.

Question 17

In a trihybrid cross (AaBbCc x AaBbCc), how many phenotypic classes are expected in the F2 generation if all genes assort independently and show complete dominance?

Accepted Answer

$$2^3 = 8$

Question 18

A researcher observes a 9:3:3:1 phenotypic ratio in the F2 generation of a cross. What does this indicate about the genes involved?

Accepted Answer

The genes assort independently and are located on different chromosomes.

Question 19

What is the formula for calculating the chi-square statistic in genetics?

Accepted Answer

$$\$$chi^2$$ = \sum \frac{(O - E)^2$}{E}$$

Transmission Genetics: Mendelian Principles, Probability, and Autosomal Inheritance

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