In a monohybrid cross of plants with red and white flowered plants, Mendel got only red flowered plants. On self-pollinating these $F_1$ plants got both red and white flowered plants in $3:1$ ratio. Explain the basis of using $RR$ and $rr$ symbols to represent the geno type of plants of parental generation.
In a monohybrid cross of plants with red and white flowered plants, Mendel got only red flowered plants. On self-pollinating these $F_1$ plants got both red and white flowered plants in $3:1$ ratio. Explain the basis of using $RR$ and $rr$ symbols to represent the geno type of plants of parental generation.
On crossing red and white flower only red colour flower appeared in the $F_{1}$ generation. But the white colour flower again appear in the $\mathrm{F}_{2}$ generation which is raised out of the $\mathrm{F}_{1}$ individuals only. Mendel reasoned that there is a factor of each and every character. Accordingly, there has to be one factor ($R$) for red flower and other one factor ($r$) for white flower. In case, an organism possess only one copy of the gene then the possibility of reappearance of white flower in the $\mathrm{F} 2$ generation of the given cross is not there. Also the ratio ($3:1$ of red and white) indicates that each organism must possess two copies of a particular gene. This is Mendel's first law of inheritance i.e law of dominance.
Similar Questions
A true breeding plant producing red flowers is crossed with a pure plant producing white flowers. Allele for red colour of flower is dominant. After selfing the plants of first filial generation, the proportion of plants producing red and white flowers in the progeny would be
A true breeding plant producing red flowers is crossed with a pure plant producing white flowers. Allele for red colour of flower is dominant. After selfing the plants of first filial generation, the proportion of plants producing red and white flowers in the progeny would be
The production of gametes by the parents, formation of zygotes, the $\mathrm{F}_{1}$ and $\mathrm{F}_{2}$ plants, can be understood from a diagram called:
The production of gametes by the parents, formation of zygotes, the $\mathrm{F}_{1}$ and $\mathrm{F}_{2}$ plants, can be understood from a diagram called:
- [NEET 2021]
$A$ : Dominance is not an autonomous feature of a gene.
$R$ : It depends as much on the gene product and the production of a particular phenotype from this product
$A$ : Dominance is not an autonomous feature of a gene.
$R$ : It depends as much on the gene product and the production of a particular phenotype from this product
Dominant allele are expressed in
Dominant allele are expressed in
Test cross in plants or in Drosophila involves crossing
Test cross in plants or in Drosophila involves crossing
- [AIPMT 2011]