Hybrid Cross
Hybrid:
A new form of plant resulting from a cross (or breeding) of different varieties of a plant is known as hybrid.
Monohybrid cross:
When we breed two pea plants having one contrasting characteristic each (of one trait each) to obtain new plants, then it is called monohybrid cross.
Dihybrid cross:
When we breed two pea plants having two contrasting characteristic each (of two traits each) to obtain new plants, then it is called dihybrid cross.
Inheriyance is the transmission of genetically controlled characteristics (or traits) from one generation to the next.
Monohybrid inheritance and the law of segregation:
According to Mendel’s first law of inheritance: The characteristics (or traits) of an organism are determined by internal ‘factors’ which occur in pairs. Only one of a pair of such factors can be present in a single gamete.
Mendel first crossed pure-bred tall pea plants with pure-bred dwarf pea plants and found that only tall pea plants were produced in the first generation or F1 generation.
Mendel concluded that the F1 generation showed the traits of only one of the parent plants: tallness, which is dominant trait and the other trait which is suppressed by the dominant trait in f1 generation is called recessive trait that is dwarfness.
Mendel then crossed the tall pea plants of the F1 generation and found that tall plants and dwarf plants were obtained in the second generation (F2 generation) in the ratio of 3:1 (three fourth plants were tall and one-fourth plants were dwarf).
Mendel concluded that the dwarf trait of parent pea plant which has seemingly disappeared in the first generation progeny, reappeared in the second generation. Mendel also noted that all the pea plants produced from the hybrid, tall plants of F1 generation were either tall or dwarf, there were no plants with intermediate hight ( or medium height) in-betwwen the tall and dwarf plants. so mendel’s experiments showed that the traits are inherited independently.
The ratio 3:1 is known as the monohybrid ratio.
A new form of plant resulting from a cross (or breeding) of different varieties of a plant is known as hybrid.
Monohybrid cross:
When we breed two pea plants having one contrasting characteristic each (of one trait each) to obtain new plants, then it is called monohybrid cross.
Dihybrid cross:
When we breed two pea plants having two contrasting characteristic each (of two traits each) to obtain new plants, then it is called dihybrid cross.
Inheriyance is the transmission of genetically controlled characteristics (or traits) from one generation to the next.
Monohybrid inheritance and the law of segregation:
According to Mendel’s first law of inheritance: The characteristics (or traits) of an organism are determined by internal ‘factors’ which occur in pairs. Only one of a pair of such factors can be present in a single gamete.
Mendel first crossed pure-bred tall pea plants with pure-bred dwarf pea plants and found that only tall pea plants were produced in the first generation or F1 generation.
Mendel concluded that the F1 generation showed the traits of only one of the parent plants: tallness, which is dominant trait and the other trait which is suppressed by the dominant trait in f1 generation is called recessive trait that is dwarfness.
Mendel then crossed the tall pea plants of the F1 generation and found that tall plants and dwarf plants were obtained in the second generation (F2 generation) in the ratio of 3:1 (three fourth plants were tall and one-fourth plants were dwarf).
Mendel concluded that the dwarf trait of parent pea plant which has seemingly disappeared in the first generation progeny, reappeared in the second generation. Mendel also noted that all the pea plants produced from the hybrid, tall plants of F1 generation were either tall or dwarf, there were no plants with intermediate hight ( or medium height) in-betwwen the tall and dwarf plants. so mendel’s experiments showed that the traits are inherited independently.
The ratio 3:1 is known as the monohybrid ratio.
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