In the context of the Hardy-Weinberg Principle, what does the variable q² represent?

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Frequency of the dominant allele.
• Frequency of the recessive allele.
• Frequency of the heterozygous genotype.
• Frequency of the homozygous recessive genotype.
Correct Option: D  [ Frequency of the homozygous recessive genotype ]

Remark: The Hardy-Weinberg equation is p² + 2pq + q² = 1. In this equation, q is the frequency of the recessive allele, and q² is the frequency of the homozygous recessive genotype.

The subject that deals with the inheritance, as well as the variation of characters from parents to offspring, is known as _______.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Genetics
• Embryology
• Taxonomy
• Ecology
Correct Option: A  [ Genetics ]

Remark: Genetics is the branch of biology that deals with the inheritance, as well as the variation of characters from parents to offspring.

Inheritance is the process by which characters are passed on from parent to progeny; it is the basis of _______.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Heredity
• Variation
• Mutation
• Recombination
Correct Option: A  [ Heredity ]

Remark: Inheritance is the process by which characters are passed on from parent to progeny; it is the basis of heredity.

Mendel investigated characters in the garden pea plant that were manifested as two opposing traits, such as tall or dwarf plants, or yellow or _______ seeds.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Green
• Brown
• Black
• Blue
Correct Option: A  [ Green ]

Remark: Mendel investigated characters in the garden pea plant that were manifested as two opposing traits, e.g., tall or dwarf plants, yellow or green seeds.

A true-breeding line is one that, having undergone continuous self-pollination, shows the stable trait inheritance and expression for several _______.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Generations
• Years
• Seasons
• Mutations
Correct Option: A  [ Generations ]

Remark: A true-breeding line is one that, having undergone continuous self-pollination, shows the stable trait inheritance and expression for several generations.

In Mendel's monohybrid cross between tall and dwarf pea plants, all plants of the first hybrid generation ($F_1$ progeny) were _______.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Tall
• Dwarf
• Medium height
• Blended
Correct Option: A  [ Tall ]

Remark: Mendel observed that all the F1 progeny plants were tall, like one of its parents; none were dwarf.

In the F2 generation of a monohybrid cross, the dwarf character, which was not seen in the F1 generation, was expressed in the proportion of _______ of the F2 plants.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• 1/4th
• 1/2
• 3/4th
• 1/8th
Correct Option: A  [ 1/4th ]

Remark: The proportion of plants that were dwarf were 1/4th of the F2 plants while 3/4th of the F2 plants were tall.

Genes which code for a pair of contrasting traits are known as _______, which are slightly different forms of the same gene.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Alleles
• Loci
• Zygotes
• Chromosomes
Correct Option: A  [ Alleles ]

Remark: Genes which code for a pair of contrasting traits are known as alleles, i.e., they are slightly different forms of the same gene.

The allelic pair of genes for height in a true breeding tall or dwarf pea variety are considered identical or _______, such as TT and tt.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Homozygous
• Heterozygous
• Dominant
• Recessive
Correct Option: A  [ Homozygous ]

Remark: In a true breeding, tall or dwarf pea variety the allelic pair of genes for height are identical or homozygous, TT and tt, respectively.

The descriptive terms, such as tall and dwarf, used to describe the appearance of a plant are called the _______.

[Principles-of-Inheritance-and-Variation] [class-xii ]

• Phenotype
• Genotype
• Allele pair
• Factor
Correct Option: A  [ Phenotype ]

Remark: TT and tt are called the genotype of the plant while the descriptive terms tall and dwarf are the phenotype.