Question 1

Gregor Mendel is known as the 'Father of Genetics' because he discovered fundamental principles of heredity. Which of the following best describes one of Mendel's key experimental approaches?

Accepted Answer

He used pea plants with many varieties and strictly controlled their mating.

Question 2

In Mendel's experiments, what is the significance of using true-breeding plants?

Accepted Answer

They ensure that offspring will always display the same trait as the parent when self-pollinated.

Question 3

Mendel crossed true-breeding purple-flowered pea plants with true-breeding white-flowered pea plants. All offspring in the F$$_1$$ generation had purple flowers. What does this result demonstrate?

Accepted Answer

The purple flower trait is dominant over the white flower trait.

Question 4

When Mendel allowed F$$_1$$ hybrids to self-pollinate, the F$$_2$$ generation showed a 3:1 ratio of purple to white flowers. Which law does this observation support?

Accepted Answer

Law of Segregation

Question 5

If a plant with genotype $$Pp ($$purple flowers) is crossed with a plant with genotype $$pp ($$white flowers), what is the expected phenotypic ratio of their offspring?

Accepted Answer

$$1:1 ($$purple:white)

Question 6

Which of the following best defines an allele?

Accepted Answer

A variant form of a gene at a particular locus on a chromosome.

Question 7

A testcross is performed between a plant with a dominant phenotype and a plant with a recessive phenotype. If all offspring display the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant ($$PP)$$

Question 8

Which of the following equations correctly represents the probability of obtaining a homozygous recessive offspring ($$aa) $$from a cross between two heterozygous parents ($$Aa 	imes Aa$$)?

Accepted Answer

$$P(aa) = \frac{1}{4}$$

Question 9

Which of the following best describes the difference between homozygous and heterozygous genotypes?

Accepted Answer

Homozygous genotypes have two identical alleles; heterozygous genotypes have two different alleles.

Question 10

In a real-world agricultural scenario, why might a farmer prefer to use true-breeding plants for crop production?

Accepted Answer

To ensure consistent and predictable traits in the crop yield.

Question 11

Which of the following is NOT a reason Mendel chose pea plants for his experiments?

Accepted Answer

They have only one type of heritable feature.

Question 12

A plant breeder wants to determine if a purple-flowered plant is homozygous or heterozygous for the purple allele. Which cross should they perform?

Accepted Answer

Cross the plant with a white-flowered plant ($$pp).$$

Question 13

If a true-breeding yellow-seeded pea plant ($$YY) is $$crossed with a true-breeding green-seeded pea plant ($$yy$$), what will be the genotype of all F$$_1$$ offspring?

Accepted Answer

$$Yy$$

Question 14

Which of the following best explains why Mendel's results were consistent with a 3:1 ratio in the F$$_2$$ generation?

Accepted Answer

Each parent contributes one of two possible alleles, which segregate independently during gamete formation.

Question 15

A geneticist observes a 3:1 ratio of dominant to recessive phenotypes in the offspring of a cross. What does this suggest about the parents' genotypes?

Accepted Answer

Both parents are heterozygous for the trait.

Mendel and the Gene Idea: Foundations of Classical Genetics

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