I am not looking for a right answer here (we will coven that in a few topics), s
ID: 272661 • Letter: I
Question
I am not looking for a right answer here (we will coven that in a few topics), simply for you to critically evaluate results and have a discussion about results. In that view, it is important that your responses to classmates extend the discussion or answer questions or misunderstandings you may detect. As such I will look more for constructive conversation than getting the right answer from the Internet, so you have to play along and show that you reflect upon the data.
German abbot Gregor Mendel published his famous pea results in 1866, to what can be described as a general shrug. Fast forward 35 year when two scientists, Hugo de Vries and Carl Correns, independently arrived to the same conclusions and rediscovered his work. This would catch the general attention and eventually redefined the fields of genetics, evolutionary biology, and population genetics (Correns' paper is available for your interest on Blackboard; de Vries' paper was written in French). In 1904, William Bateson, Edith Saunders, and Reginald Punnett (of the Punnett square fame) published odd results: when selfing pea plants investigating pollen shape and flower color, the F2 generation deviated dramatically from the Mendelian 9:3:3:1 ratio expected of the F2 generation looking at 2 traits: Phenotype Purple, long Purple, round Red, long Red, round Observed Expected 1528 1199 106 400 400 381 133 Total 2132 2132 Discuss how and why those numbers deviate from Mendelian expectations (i.e is there any pattern of divergence in the data ?: what might be causing this divergence?) Why are these surprising or not surprising? Note that purple flowers and long pollen are the dominant phenotypes, while red flowers and round pollen are recessiveExplanation / Answer
Mendel took two years to obtain true-breeding plants, i.e, the cross between two similar parent plants produced offsprings with the same phenotype as of parents (but not any other phenotypes).
After Mendel, several other botanists tried the mating between plants as Mendel did. However, they did not obtain similar results.
For example, the genotype of purple flowers can be PP or Pp. Mendel selected only PP plants. Others may have also selected Pp plants.
The selection of true breeding plants played a major role in contributing to Mendel’s success.
In this experiment even, the scientists might not have spent enough time in selecting true breeding plants.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.