Explain Mendel's monohybrid cross experiment taking tall and dwarf pea plants as an example. Clearly state the phenotypic and genotypic ratios in the F1 and F2 generations, and explain the Law of Segregation based on this.

Q: Explain Mendel's monohybrid cross experiment taking tall and dwarf pea plants as an example. Clearly state the phenotypic and genotypic ratios in the F1 and F2 generations, and explain the Law of Segregation based on this.

Introduction to Monohybrid Cross\nA monohybrid cross is a genetic cross between two individuals involving variation in only one specific trait of interest. Gregor Mendel used pea plants to study the inheritance of contrasting characters, such as plant height (tall vs. dwarf). Experimental Setup and Steps Parent Generation (P): Mendel selected pure-breeding (homozygous) tall pea plants (TT) and pure-breeding dwarf pea plants (tt). F1 Generation (First Filial Generation): When these pure parents were cross-pollinated, all the offspring in the F1 generation were tall (Tt). The trait for dwarfness did not appear in the F1 generation. This led Mendel to formulate the concept of dominance, where the tall trait is dominant over the recessive dwarf trait. Self-pollination of F1 Generation: When the F1 tall plants (Tt) were self-pollinated, both tall and dwarf plants appeared in the F2 generation. F2 Generation Ratios Phenotypic Ratio: Out of 4 plants in the Punnett square combination, 3 were tall and 1 was dwarf. Thus, the phenotypic ratio is 3 : 1 (Tall : Dwarf). Genotypic Ratio: The genetic constitution reveals one homozygous tall (TT), two heterozygous tall (Tt), and one homozygous dwarf (tt). Thus, the genotypic ratio is 1 : 2 : 1 (TT : Tt : tt). Law of Segregation (First Law of Mendel)\nBased on the monohybrid cross, Mendel proposed the Law of Segregation. It states that alleles of a gene separate during gamete formation so that each gamete carries only one allele for each gene. Even though the F1 plants received one tall and one dwarf allele (Tt), they did not blend; instead, they remained discrete and separated cleanly during gamete production. Conclusion\nThe monohybrid cross successfully established the particulate nature of inheritance, proving that hereditary units do not blend but segregate independently during gamete formation.

Question

Accepted Answer

Introduction to Monohybrid Cross
A monohybrid cross is a genetic cross between two individuals involving variation in only one specific trait of interest. Gregor Mendel used pea plants to study the inheritance of contrasting characters, such as plant height (tall vs. dwarf). Experimental Setup and Steps Parent Generation (P): Mendel selected pure-breeding (homozygous) tall pea plants (TT) and pure-breeding dwarf pea plants (tt). F1 Generation (First Filial Generation): When these pure parents were cross-pollinated, all the offspring in the F1 generation were tall (Tt). The trait for dwarfness did not appear in the F1 generation. This led Mendel to formulate the concept of dominance, where the tall trait is dominant over the recessive dwarf trait. Self-pollination of F1 Generation: When the F1 tall plants (Tt) were self-pollinated, both tall and dwarf plants appeared in the F2 generation. F2 Generation Ratios Phenotypic Ratio: Out of 4 plants in the Punnett square combination, 3 were tall and 1 was dwarf. Thus, the phenotypic ratio is 3 : 1 (Tall : Dwarf). Genotypic Ratio: The genetic constitution reveals one homozygous tall (TT), two heterozygous tall (Tt), and one homozygous dwarf (tt). Thus, the genotypic ratio is 1 : 2 : 1 (TT : Tt : tt). Law of Segregation (First Law of Mendel)
Based on the monohybrid cross, Mendel proposed the Law of Segregation. It states that alleles of a gene separate during gamete formation so that each gamete carries only one allele for each gene. Even though the F1 plants received one tall and one dwarf allele (Tt), they did not blend; instead, they remained discrete and separated cleanly during gamete production. Conclusion
The monohybrid cross successfully established the particulate nature of inheritance, proving that hereditary units do not blend but segregate independently during gamete formation.

CBSE · Class 10 · Science · HeredityExplain Mendel's monohybrid cross experiment taking tall and dwarf pea plants as an example. Clearly state the phenotypic and genotypic ratios in the F1 and F2 generations, and explain the Law of Segregation based on this.

Introduction to Monohybrid Cross\nA monohybrid cross is a genetic cross between two individuals involving variation in only one specific trait of interest. Gregor Mendel used pea plants to study the inheritance of contrasting characters, such as plant height (tall vs. dwarf).

Experimental Setup and Steps

F2 Generation Ratios

Conclusion\nThe monohybrid cross successfully established the particulate nature of inheritance, proving that hereditary units do not blend but segregate independently during gamete formation.