Understanding Dominant and Recessive Traits
* Dominant Trait: A trait that is expressed even if only one copy of the dominant allele is present.
* Recessive Trait: A trait that is only expressed if two copies of the recessive allele are present.
The Problem of Hidden Alleles
* Example: Let's say a flower color gene has two alleles: purple (P, dominant) and white (p, recessive).
* A plant with PP or Pp will have purple flowers because purple is dominant.
* Only a plant with pp will have white flowers.
How to Figure Out Genotype
To determine a plant's genotype, you need additional information, such as:
* Test Cross: Cross the plant in question with a homozygous recessive individual (pp in our flower example).
* If the offspring all have purple flowers, the plant was homozygous dominant (PP).
* If some offspring have white flowers, the plant was heterozygous (Pp).
* Family History: Analyzing the traits of the plant's parents and siblings can provide clues about its genotype.
* Molecular Techniques: DNA analysis can directly determine the alleles present in a plant's genotype.
In Conclusion:
While you can observe the dominant phenotype, you can't definitively determine the genotype without further investigation. You need to look for evidence that reveals whether the plant carries one or two copies of the dominant allele.
