Question 1

When Mendel crossed two plants that were heterozygous for a single trait, what was the phenotypic ratio of their offspring?

Accepted Answer

When two heterozygous plants are crossed for a single trait, the offspring will have a 3:1 phenotypic ratio, with three individuals showing the dominant trait and one individual showing the recessive trait. This is because the heterozygous parent can produce two different types of gametes (one carrying the dominant allele and the other carrying the recessive allele) in equal proportions, which will then combine randomly with the gametes from the other parent to produce the offspring. This is known as Mendel's law of segregation.

Question 2

An individual who has two identical alleles for a trait is said to be .

Accepted Answer

An individual who has two identical alleles for a trait is said to be homozygous.

Question 3

The stamen represents the portion of the plant, while the ovules represent the portion of the plant.

Accepted Answer

The stamen is the male reproductive organ of a flower, while the ovules are the female reproductive organs.

Question 4

Mendel's work with two-factor (dihybrid) crosses led directly to which of the following?

Accepted Answer

Mendel's work with two-factor crosses led directly to the discovery of the law of independent assortment, which states that the inheritance of one trait is not dependent on the inheritance of another trait.

Question 5

The genetic composition of an individual is called its .

Accepted Answer

Genotype refers to an individual's genetic makeup, whereas phenotype refers to its observable traits. Hybrid refers to an offspring resulting from the cross-breeding of two different species or varieties, and dominance refers to the expression of one allele over another in a heterozygous individual. None of the answers are correct is not a valid choice in this case as one of them is correct.

Question 6

Mendel's work with single-factor crosses resulted in the development of which of the following?

Accepted Answer

Mendel's work with single-factor crosses led to the law of segregation, which states that each individual has two alleles for a trait and only one is passed down to offspring.

Question 7

Differences in plant flower color or plant height are called a variant of a trait.

Accepted Answer

Variants of a trait are differences or variations within a specific trait, such as different flower colors or varying heights in plants.

Question 8

When studying a genetic cross, the second generation following the initial cross is identified by which of the following?

Accepted Answer

The second generation following the initial cross is identified as the F2 generation. The P generation is the parental generation, the F1 generation is the first generation of offspring from the parental cross, the F3 generation is the third generation of offspring, and the P3 generation is the third generation of parental breeding.

Question 9

An individual who has two different alleles for a trait is called .

Accepted Answer

An individual who has two different alleles for a trait is called heterozygous. Haploid refers to having only one set of chromosomes, homozygous refers to having two identical alleles for a trait, isozygous is not a commonly used term, and true-breeding refers to a homozygous individual that always produces offspring with the same phenotype.

Question 10

Which of the following traits was not studied by Mendel?

Accepted Answer

Mendel did not study pollen color, as it was not a visible trait that could easily be observed and categorized. Instead, he focused on traits such as flower color, seed color, pod color, and plant height.

Question 11

The theory of pangenesis was first proposed by .

Accepted Answer

Hippocrates first proposed the theory of pangenesis, suggesting that particles from all over the body contribute to the genetic material passed to offspring.

Question 12

When Mendel crossed two plants that were heterozygous for a single trait, what was the genotypic ratio of their offspring?

Accepted Answer

The genotypic ratio for the offspring of two heterozygous plants for a single trait is 1:2:1, representing one homozygous dominant, two heterozygous, and one homozygous recessive genotype.

Question 13

Which of the following is correct regarding the blending theory of inheritance?

Accepted Answer

The blending theory of inheritance suggested that offspring are a mix of parental traits, and it was widely accepted before Mendel's work. Joseph Kölreuter's research supported this idea, and it was believed that traits could change through blending.

Question 14

The observable characteristics of an organism are called its .

Accepted Answer

Phenotype refers to the physical and observable characteristics of an organism, including traits such as eye color, height, and hair texture. Genotype, on the other hand, refers to the genetic makeup of an organism, including its inherited alleles or genes. Dominance refers to the relationship between different alleles, where one may be expressed more strongly over another, while genes are the genetic instructions that code for specific traits. Thus, the best choice for this question is A) Phenotype.

Question 15

Mendel's work on inheritance had an immediate influence on the scientific community and theories of
inheritance.

Accepted Answer

Mendel's work was largely ignored by the scientific community until it was rediscovered in 1900, more than three decades after its publication.

Question 16

In a Punnett square diagram, the outside of the box represents the .

Accepted Answer

The answer of In a Punnett square diagram, the outside...

Question 17

Mendel's work with monohybrid crosses provided proof of which of the following?

Accepted Answer

Mendel's work with monohybrid crosses provided proof for the particulate theory of inheritance, which suggests that inheritance is determined by discrete units of inheritance (later known as alleles) rather than through blending of traits.

Question 18

Mendel's work was rediscoved in 1900 by which of the following individual(s)?

Accepted Answer

Mendel's work was independently rediscovered by three individuals: Carl Correns, Erich von Tschermak, and Hugh de Vries in 1900, making all of the answer choices correct.

Question 19

A true breeding line of green pod pea plants is crossed with a true-breeding line of yellow pod plants. All of their offspring have green pods. From this information, it can be stated that the green color is
To the yellow color.

Accepted Answer

The green pod color is dominant over the yellow pod color, as all offspring from the cross have green pods, indicating that the green allele masks the expression of the yellow allele.

Question 20

Which of the following characteristics made the pea plant Pisum sativum an ideal organism for Mendel's studies?

Accepted Answer

All three characteristics listed (ability to self-fertilize, ease of cross-fertilization, and easily identifiable traits) made the pea plant an ideal organism for Mendel's studies.

Quiz 2: Mendelian Inheritance