Question 1

Which aspect of Mendel's experimental design most directly ensured that his results could be replicated by other scientists?

Accepted Answer

Quantification of results and use of test-cross analysis

Question 2

A mono-hybrid cross between two heterozygous pea plants (Rr x Rr) produces 4000 offspring. According to Mendel’s Law of Segregation, how many offspring are expected to show the recessive phenotype?

Accepted Answer

1000

Question 3

Which equation is used to calculate the chi-square ($$\$$chi^2$$) value in genetics to test if observed data fit expected Mendelian ratios?

Accepted Answer

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

Question 4

In a dihybrid cross (RrYy x RrYy), what is the expected ratio of phenotypes in the F2 generation according to Mendel’s Law of Independent Assortment?

Accepted Answer

9:3:3:1

Question 5

A test cross is performed between a plant with an unknown genotype and a homozygous recessive plant. If all offspring show the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 6

Which molecular event best explains the difference between Mendel’s tall and short pea plant alleles?

Accepted Answer

A mutation resulting in an amino acid change in the gibberellin gene

Question 7

If the observed data from a genetic cross do not match the expected Mendelian ratio, which statistical test should be used to determine if the deviation is due to chance?

Accepted Answer

Chi-square test

Question 8

In Mendel’s Law of Segregation, when do alleles separate so that each gamete receives only one allele?

Accepted Answer

During gamete formation (meiosis)

Question 9

A pedigree shows a trait that appears in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 10

If a parent is heterozygous for two genes (RrYy), what is the probability that a gamete will contain both recessive alleles (r and y)?

Accepted Answer

$$\frac{1}{4}$$

Question 11

Which of the following human traits is known to follow Mendelian inheritance?

Accepted Answer

Blue-yellow color blindness

Question 12

In a chi-square test, what does a p-value less than 0.05 indicate about the null hypothesis?

Accepted Answer

The null hypothesis should be rejected

Question 13

If you cross a heterozygous tall pea plant (Tt) with a homozygous short plant (tt), what proportion of the offspring will be tall?

Accepted Answer

$$\frac{1}{2}$$

Question 14

Which rule is used to calculate the probability of two independent genetic events occurring together?

Accepted Answer

Product rule: multiply probabilities of independent events

Question 15

A scientist observes a 3:1 ratio of round to wrinkled seeds in a pea plant cross. What does this suggest about the inheritance of the trait?

Accepted Answer

Round is dominant to wrinkled and follows Mendelian inheritance

Question 16

In a dihybrid cross, what is the probability of obtaining an offspring that is homozygous recessive for both traits?

Accepted Answer

$$\frac{1}{16}$$

Question 17

Which of the following best describes the purpose of a test cross in genetics?

Accepted Answer

To determine the genotype of an individual with a dominant phenotype

Question 18

If the degrees of freedom in a chi-square test are 1, how many phenotypic classes were analyzed?

Accepted Answer

2

Question 19

Which of the following is NOT a reason Mendel’s experiments were successful?

Accepted Answer

He used traits with indistinguishable phenotypes

Question 20

A parent with genotype RrYy produces gametes. What fraction of gametes will be rY?

Accepted Answer

$$\frac{1}{4}$$

Mendelian Genetics: Principles, Experimental Design, and Statistical Analysis

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