Question 1

Which of the following best explains why the blending hypothesis was rejected in favor of Mendel’s laws of inheritance?

Accepted Answer

The blending hypothesis could not explain the reappearance of traits after several generations, whereas Mendel’s laws showed that traits are inherited as discrete units.

Question 2

A true-breeding pea plant with purple flowers is crossed with a true-breeding pea plant with white flowers. All offspring in the F1 generation have purple flowers. Which term best describes the purple flower allele?

Accepted Answer

Dominant allele

Question 3

In a monohybrid cross between two heterozygous pea plants (Pp × Pp), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$3:1$$

Question 4

Which of the following best distinguishes between genotype and phenotype?

Accepted Answer

Genotype refers to the genetic makeup of an organism, while phenotype refers to the observable traits.

Question 5

A testcross is performed between a pea plant with an unknown genotype for flower color (purple) and a white-flowered plant (homozygous recessive). If all offspring have purple flowers, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 6

Which event during meiosis is most directly responsible for Mendel’s law of segregation?

Accepted Answer

Separation of homologous chromosomes during anaphase I

Question 7

In a dihybrid cross between two heterozygous pea plants (YyRr × YyRr), where Y = yellow seed, y = green seed, R = round seed, r = wrinkled seed, what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 8

Which aspect of meiosis supports Mendel’s law of independent assortment?

Accepted Answer

Random orientation of homologous chromosome pairs during metaphase I

Question 9

A pedigree shows that a certain trait 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

Which of the following is an example of incomplete dominance?

Accepted Answer

A cross between red-flowered and white-flowered snapdragons produces pink-flowered offspring.

Question 11

Which pattern of inheritance is illustrated when both alleles in a heterozygote are fully expressed, such as in human blood type AB?

Accepted Answer

Codominance

Question 12

A single gene affects multiple traits in an organism. This phenomenon is known as:

Accepted Answer

Pleiotropy

Question 13

Which of the following best describes the chromosomal theory of inheritance?

Accepted Answer

Genes are located on chromosomes, and the behavior of chromosomes during meiosis accounts for inheritance patterns.

Question 14

A woman who is a carrier for a recessive X-linked disorder and a man who does not have the disorder have a son. What is the probability that their son will have the disorder?

Accepted Answer

$$50\%$$

Question 15

Which of the following is a real-world example of a dominant genetic disorder?

Accepted Answer

Huntington’s disease

Question 16

If a heterozygous individual (Aa) is crossed with a homozygous recessive individual (aa), what is the expected genotypic ratio of their offspring?

Accepted Answer

$$1:1$$

Question 17

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry the same genes but may have different alleles.

Question 18

A genetic counselor is analyzing a pedigree for a rare recessive disorder. Which pattern would most likely indicate a recessive inheritance?

Accepted Answer

The disorder skips generations and appears only when both parents are carriers.

Question 19

Which of the following best describes a hybrid organism?

Accepted Answer

An organism produced by crossing two different true-breeding varieties.

Question 20

Which of the following scenarios best illustrates Mendel’s law of independent assortment?

Accepted Answer

A plant with yellow, round seeds produces offspring with all combinations of seed color and shape when crossed with a plant with green, wrinkled seeds.

Study Guide for Patterns of Inheritance (General Biology I - Mendelian Genetics)

Guida di studio - Domande di pratica

Study guide - Flashcard