Experiment with corn?
A mutation in maize plants resulted in a recessive gene variant (a). In the experiment, plants that were homozygous for this gene variant (aa) turned pale green at germination temperatures below 20 °C.
- Describe the procedure and results of the experiment in Figure 5. Using this example, explain the differences between genetic variability and modifier variability.
- Explain the evolutionary significance of the preservation of recessive gene variants in diploid organisms.
Two plants with the same genotype are simply crossed, and then they produce four plants with different genotypes. All of them are green at a germination temperature below 20 degrees Celsius, but the plants with the recessive gene variant are pale green at a temperature below 20 degrees Celsius. That's all you can conclude from this figure, isn't it? Regarding task 2, I'm not sure what evolutionary significance it has, other than that it can produce a different phenotype and thus increase the mediational variability. Can you say more about this? If so, it would be really nice if someone could add something or explain it in more detail 🙂
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I would add the following
To the 1:
The genetic variability depends on the inheritance of the alleles (A/a). The variability is determined by environmental influences, whereby the phenotype, such as the color of the plants, changes at temperatures below 20° C.
and to the 2:
The advantage of obtaining recessive gene variants is that they increase the genetic diversity and serve as a genetic reservoir. Heterocygotes (Aa) may in some cases have an advantage over homocygotes (AA or aa) (especially in humans).