Question 1

Gregor Mendel's experiments with pea plants led to the formulation of the Law of Segregation. Which of the following best describes this law?

Accepted Answer

During gamete formation, the two alleles for a trait separate so that each gamete receives only one allele.

Question 2

In Mendel's pea plant experiments, the cross between a true-breeding purple-flowered plant (PP) and a true-breeding white-flowered plant (pp) produced all purple-flowered offspring in the F1 generation. What is the genotype of these F1 offspring?

Accepted Answer

$$Pp$$

Question 3

If two heterozygous pea plants ($$Pp) $$are crossed, what is the expected phenotypic ratio of purple to white flowers in the F2 generation?

Accepted Answer

$$3:1$$

Question 4

Which of the following best explains why Mendel chose pea plants for his genetic experiments?

Accepted Answer

Pea plants have many readily distinguishable traits and can self-fertilize or be cross-fertilized.

Question 5

A plant with genotype $$Pp is $$crossed with a plant with genotype $$pp. $$What percentage of the offspring are expected to have purple flowers?

Accepted Answer

$$50\%$$

Question 6

Which term describes the condition where an organism has two identical alleles for a gene?

Accepted Answer

Homozygous

Question 7

In a dihybrid cross between pea plants with genotypes $$RrYy ($$round yellow seeds) and $$RrYy$$, what is the expected phenotypic ratio for the offspring?

Accepted Answer

$$9:3:3:1$$

Question 8

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are different forms of a gene found at the same locus on homologous chromosomes.

Question 9

A pea plant with genotype $$Yy$$ produces gametes. What proportion of its gametes will carry the $$Y$$ allele?

Accepted Answer

$$50\%$$

Question 10

Which of the following best describes the Law of Independent Assortment?

Accepted Answer

Alleles for different traits separate independently during gamete formation.

Question 11

If a plant has the genotype $$Rr$$, what are the possible gametes it can produce for the $$R$$ gene?

Accepted Answer

$$R$$ and $$r$$

Question 12

In a cross between two pea plants, one with genotype $$YY$$ and one with genotype $$yy$$, what will be the genotype of all F1 offspring?

Accepted Answer

$$Yy$$

Question 13

Which of the following is an example of a phenotype?

Accepted Answer

Round seed shape

Question 14

A true-breeding pea plant with yellow seeds ($$YY) is $$crossed with a true-breeding pea plant with green seeds ($$yy). If $$the F1 generation is self-fertilized, what is the expected genotypic ratio in the F2 generation?

Accepted Answer

$$1 YY : 2 Yy : 1 yy$$

Question 15

Which of the following best explains why two plants with the same phenotype might have different genotypes?

Accepted Answer

Dominant alleles can mask the presence of recessive alleles in heterozygotes.

Question 16

In Mendel's experiments, what was the purpose of removing the stamens from pea flowers before cross-fertilization?

Accepted Answer

To prevent self-fertilization and allow controlled cross-fertilization.

Question 17

Which of the following is true about homologous chromosomes?

Accepted Answer

They carry genes for the same traits at the same loci, but may have different alleles.

Question 18

A pea plant with genotype $$rryy is $$crossed with a plant with genotype $$RRYY. $$What is the genotype of the F1 offspring?

Accepted Answer

$$RrYy$$

Question 19

Which of the following best describes a testcross?

Accepted Answer

A cross between an individual with a dominant phenotype and a homozygous recessive individual to determine the genotype of the dominant parent.

Question 20

If a pea plant with genotype $$Pp ($$purple flowers) is self-fertilized, what fraction of the offspring will be homozygous for the purple allele?

Accepted Answer

$$1/4$$

Mendelian Genetics: Principles of Heredity and Inheritance in Pea Plants

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