Answer :
Certainly! Let's go through the problem step-by-step to understand the genetic makeup of the red geranium parent.
1. Understand the Genetics Involved:
- The red flower trait is governed by the allele "R". Red flowers can appear with genotypes "RR" (homozygous) or "Rr" (heterozygous).
- The white flower trait is governed by the allele "r". White flowers appear only with the genotype "rr" (homozygous).
2. Observations from the Cross:
- The horticulturalist crossed a red geranium with an uncertain genetic makeup with a white geranium, which must be "rr" since it's white.
- The offspring consists of half red-flowered plants and half white-flowered plants.
3. Determining the Genetic Makeup of the Red Geranium:
- If the red geranium was "RR," all offspring would have received an "R" allele from this parent and an "r" allele from the white geranium, resulting in all "Rr" red-flowered offspring.
- Since there are both red and white flowers in the offspring, the red parent must be able to contribute either an "R" or an "r" allele.
4. Conclusion of the Genetic Makeup:
- The presence of both red and white flowers among the offspring indicates that the red geranium parent must have been "Rr" (heterozygous). This way, it could pass on either the "R" allele for red flowers or the "r" allele for the potential for white flowers.
Therefore, the red geranium is heterozygous for red flowers, with the genotype "Rr".
1. Understand the Genetics Involved:
- The red flower trait is governed by the allele "R". Red flowers can appear with genotypes "RR" (homozygous) or "Rr" (heterozygous).
- The white flower trait is governed by the allele "r". White flowers appear only with the genotype "rr" (homozygous).
2. Observations from the Cross:
- The horticulturalist crossed a red geranium with an uncertain genetic makeup with a white geranium, which must be "rr" since it's white.
- The offspring consists of half red-flowered plants and half white-flowered plants.
3. Determining the Genetic Makeup of the Red Geranium:
- If the red geranium was "RR," all offspring would have received an "R" allele from this parent and an "r" allele from the white geranium, resulting in all "Rr" red-flowered offspring.
- Since there are both red and white flowers in the offspring, the red parent must be able to contribute either an "R" or an "r" allele.
4. Conclusion of the Genetic Makeup:
- The presence of both red and white flowers among the offspring indicates that the red geranium parent must have been "Rr" (heterozygous). This way, it could pass on either the "R" allele for red flowers or the "r" allele for the potential for white flowers.
Therefore, the red geranium is heterozygous for red flowers, with the genotype "Rr".
