Mendelian Genetic Inheritance
General Biology I (Southern New Hampshire University)
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Mendelian Genetic Inheritance
Student Name
Date
Data
Activity 1
Data Table 2
Photos
Photos
Data Table 1
Number of Plants with: P1
Generation
P1
Generation
Percentage
F
1
Generation
F1
Generation
Percentage
purple stem and dwarf
stem height 0 0 2 20 %
purple stem and normal
stem height 10% 5 50 % 1
non-purple stem and
dwarf stem height % 1 10 % 3 30
non-purple stem and
normal stem height 6 60% 2 % 20
total number of plants10 100% 10 100 %
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1. Is the Purple Stem trait dominant or recessive? Support your conclusion with examples
from your laboratory observations.
Although my plants didn’t grow very much, it can still be observed that the purple stem trait is
dominant. When looking at my data, it can be observed that there are definitely more purple
stems than green stems in both of my experiments. In our Lab reading we learn that “When two
different alleles are present, the trait that is expressed is dominant; the allele that is not expressed
is recessive” (Carolina Distance Learning, 2020). This shows that the dominant trait is the purple
stem because there were far more purple stems than green.
1. Is the dwarf stem trait dominant or recessive? Support your conclusion with examples
from your laboratory observations.
Number of Plants with:
F2
Generation
Prediction
F2
Generation
Percentage
Prediction
F2
Generation
Actual
F2
Generation
Percentage
Actual
purple stem and dwarf
stem height 5 10% 5 10 %
purple stem and normal
stem height 50% 25 50 % 25
non-purple stem and
dwarf stem height 5 10% 5 10 %
non-purple stem and
normal stem height 15 30% 10 20 %
total number of plants 50 100% 45 90 %
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Although my plants didn’t grow very much, the dwarf stem trait is definitely recessive here.
When looking at the data I collected, the dwarf stem percentage is less than that of the regular
sized stems. Given that there are more long stems, the dwarf stem trait is clearly recessive. Going
off of this, according to our lab, dwarf stems are “Stems that are shorter than a plant with a
normal stem” (Carolina Distance Learning, 2020). I don’t see any stems that appear to be smaller
than the others besides for the seeds that have not grown. This is why I believe the dwarf stem
trait to be recessive.
1. Based on your observations, what are the phenotype and genotype of the P1 plant? What
did you deduce to be the genotype and phenotype of the P2?
Based on my observations, the phenotype of the P1 plant is a non purple stem and a normal stem
height. This means that the genotype here would be TtYY. I deduced this genotype and
phenotype from the data. The data shows that a purple stem is recessive and the normal stem
height is dominant recessive therefore concluding that P2 would be non purple stem and dwarf
stem height: ttYy.
1. Based on your observations, draw the Punnett square for the cross of the P1 and P2
parental plants.
1. Based on your observations, draw the Punnett square for the cross of the F1 plants.
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a. Based on the Punnett square above, what is the percentage of offspring that are predicted
to have purple
stems and dwarf stem height? How did this compare to the results that you obtained in
this lab?
The percentage of offspring that are predicted to have purple stems and dwarf stem height are
25%. This is compared to the results of this lab because the P1 generation had a recessive purple
stem phenotype, which is different from the dominant purple stem phenotype seen in the F1
generation.
b. Based on the Punnett square above, what is the percentage of offspring that are predicted
to have nonpurple stems and dwarf stem height? How did this compare to the results that
you obtained in this lab?
The percentage of offspring that are predicted to have non-purple stems and a dwarf stem height
is 25%. This is compared to the results of this lab because the P1 generation had a recessive
purple stem height, and therefore differs from the F1 generation, which had a dominant purple
stem. On top of this, looking at the F2 generations it can also be concluded that they too had a
dominant purple stem.
c. Based on the Punnett square above, what is the percentage of offspring that are predicted
to have purple stems and normal stem height? How did this compare to the results that
you obtained in this lab?
The percentage of offspring that are predicted to have purple stems and a normal stem height is
50%. This is similar to the results obtained in this lab because throughout the F1 and F2
generations, purple stems with normal stem height are dominant. In other words, this percentage
is a lot closer to the results I obtained in my lab.
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d. Based on the Punnett square above, what is the percentage of offspring that are predicted
to have nonpurple stems and normal stem height? How did this compare to the results
that you obtained in this lab?
The percentage of offspring that are predicted to have non-purple stems and normal stem height
is 25%. This compares to the results I obtained in this lab because non purple stems were
recessive in the F1 and F2 generations ( but not in the P1 generations). However, normal stem
height was dominant throughout all generations.
Sources:
Carolina Distance Learning, 2020
