Answer:
2. 1 Pink : 1 white
3. 1 Red : 1 Pink
4. 1 Red : 2 Pink : 1 White
Explanation:
This question involves a single gene coding for flower colour in snapdragon plants. The alleles of the gene exhibits incomplete dominance i.e. the red allele (R) ia not completely dominant over the white allele (W), hence an intermediate pink phenotype (RW) is formed. Based on this, a red snapdragon will have genotype, CRCR while a white one will have genotype, CWCW. The intermediate pink phenotype will have a genotype, CRCW.
The image attached to this question shows four crosses between different traits.
In the second cross between a pink (CRCW) and white offspring (CWCW), 2pink and 2white offsprings will be possibly produced in the ratio 1:1.
In the third cross between a red (CRCR) and pink (CRCW) snapdragon, 2 red and 2 Pink offsprings will possibly be produced in a ratio 1:1.
In the fourth cross between a pink (CRCW) and pink (CRCW) snapdragon, red, pink and white offsprings will be produced in the ratio 1:2:1.
See attached image for the complete punnet square. Note that, there was a mistake in the Genotype of the last cross i.e. pink has genotype CRCW not CWCW.
