1. Section #6 December 4, 2012
Kendall Marine
Anthocyanin: Inheritance Pattern
Jecelin Espinal, Brittany Feiten, Emily Hornet, Karina
Abstract
During this semester in lab, the class conducted an experiment that explored the
inheritance of traits in the plant, Brassica Rapa. The Mendelian model aided the class, as we
used it in order to develop a hypothesis regarding the patterns of inheritance found in the plant,
Brassica Rapa.After conducting the experiment the group came to conclude, that due to the
presence of purple pigment (anthocyanin) contrived to be a dominant trait and followed Mendel
laws. Overall, the results were inconclusive to the fact that trial and error played a critical role in
the experiment.
Introduction
Gregor Mendel was an Australian monk who discovered the basic ideas of heredity
through experiments he conducted in his own garden. Around 1854, Mendel began to conduct
experiments about the communication of hereditary traits in plant hybrids. During Mendel’s time
it was universally accepted that a hybrid would return to its original form, and was incapable of
creating new forms. Through various year of hard work, Mendel found many new ideas that are
now known to be “Mendelian Laws”. One of the laws he discovered was the laws of segregation,
this concluded that there are dominant and recessive traits passed on casually from parent to
offspring. Another law called, the Law of Independent Assortment, concluded that traits were
passed on autonomously of other traits from parent to offspring. Overall, Mendel’s laws played a
huge role not only in genetics but biologically as well. Gregor Mendel’s laws showed the pattern
of inheritance from parent to in and also provided reasons for variations seen in the offspring.
Throughout the semester the general 1 bio class conducted an experiment that put
Mendelian Genetics to the test. The scientific question asked was, does the inheritance pattern of
anthocyanin (purple pigment) follow Mendelian Laws? The group hypothesized that the
presence of purple pigment (anthocyanin) is inherited as a dominant trait and does follow
Mendelian laws. Before experimenting the class predicted, if anthocyanin is inherited as a
dominant trait, then the F2 generation will follow Mendelian genetics resulting in 3:1 phenotypic
ratio.
In order to carry out the experiment the class used the fast plants which contain strains of
Brassica Rapa. According to our lab manual it stated, that the Brassica Rapa have a rapid
breeding cycle from seed to seed in 35 days. Due to their rapid breeding cycle, plants in the
Brassica family are ideal models for teaching and research. In the experiment conducted the class
investigated these traits: presence or absence of anthocyanin, yielding green or purple of purple
plants, and color of plant.

2. Materials and Methods
Before conducting the experiment obtain the following materials in order to complete
successful research. Obtain seeds of designated phenotypes, a seed collecting pan, a few small
envelopes, wicks, labeling tape, Styrofoam quads, and a florescent light bank. Also, obtain water,
a dropper, a potting mix, fertilizer pellets, a watering tray, and a petri dish with filter paper. Once
you obtain these materials the experiment can be conducted accordingly.
Table 2
Approximate Date Date Activity Initials
Day 1 08/21/12 Plant F1 hybrid seeds. J.E.
Regularly check
water.
(See planting seeds)
Day 4 or 5 Observe seedlings and J.E.
record number of each
phenotype in Table 3.
Thin plants to one per
cell.
Days 14,16,20 Pollinate on 3 days; J.E.
pollinate at least 6-8
followers.
(See pollinating
flowers)
Days 20 to 39 Remove buds and J.E.
shoots.
Day 39 Harvest F2 seeds and J.E.
germinate in petri
dishes.
(See Harvesting &
Germinating seeds)
Day 42 Count and record J.E.
number of each
phenol type in Table
4.
Table above as seen in the lab manual by Dr. Tod Duncan. “The Pearson Custom Library
for the Biological Sciences. Symbiosis.
In order to complete the experiment successfully you need to obtain the following materials from
you biology lab instructor. First you will need 12 F1 seeds that resulted from the cross between a
homozygous plant that contained anthocyanin and a true- breeding plant that did not contain
anthocyanin. Next, obtain 1 quad and other planting supplies. After, get 2 mature plants with
parental phenotypes. After all the above is complete, obtain 6 seeds from homozygous green
plants, and 6 seeds from the homozygous variegated plants. Then, obtain 2 quads that will be

3. used to plant the seeds. After, get 5 inch by 8 inch index cards that will be used later on in the
experiment. Finally, obtain a few stakes or small wooden applicator sticks.
The following procedure must be followed in order to plant the seeds, pollinate the
flowers, and harvest and germinate the seeds of the next generation. In order to plant the seeds
correctly they must follow the following. In each cell of the quad add one wick. Make sure the
wicks tips extended from the holes in the bottom. Then add plotting soil to each cell of the quad
until it was half full. Adding a little more soil and pressing down on the soil with a finger until a
depression is present. Then, add two or three seeds to each cell and cover it up with soil. Obtain a
dropper and water each cell with the seeds until the water drips from the wick. After, the
dripping occurred they placed the quad on a watering tray and placed in under a florescent light
bank. Make sure the lights were maintained 2-3 inches above the growing plants and on for 24
hours a day. After, placing it under the light bank, label the quad with their names, the date, and
the plant types. After 4 to 5 days they went back to the light bank, and recorded the phenotypes,
they removed all but one of the large healthy seedlings in each cell. Next allow two or three
flowers to open up on most of the plants. Approximately wait 14 days after the planting of the
seeds. She went with her group and they used a “bee-stick”, which was made by gluing a dry
honeybee thorax to the top of a toothpick, they transferred pollen from one plant to another one.
After, she saved the stick by inserting it into one cell of the quad. She then used the stick to
pollinate again 2 to 4 days later. After, the third pollination her group pinched off all the
unopened buds. Then, they removed and disregarded of all the new buds and shoots for the
following two weeks. After, 21 days after the pollination the seeds were ready to harvest. They
removed the quad with the plants from the watering tray and dried it for 5 days. After, she
removed all the dry seed pods and rolled them between her hands over the collecting pan to free
the seeds from the pod. They took the seeds and stored them in an envelope and labeled it with
their names, the date, and the seed type. Following they germinated the seeds by moistening a
piece of filter paper in the petri dish, labeling the paper with their name, the date, and the seed
type. They made sure they poured off any excess water. Then, they placed 25 of the harvested
seeds in neat rows in the upper thirds of the filter paper. She then placed the petri dish tilted on
end in a water reservoir and added 2cm of water. The whole class placed the dish and reservoir
under the light bank. After 46-98 hours passed, they observed the seedlings and recorded the
phenotypes in the appropriate table. The group recorded the results, and performed the chi-
square on the class results.
Results
(Table 4)
Team No. Purple Number of Plants No.
Green Team Purple Green
1 10 26 7 7 12
2 25 13 8
3 13 42 9
4 10 31 10
5 43 4 11
6 6 3 12
Class total Purple: 130 Green: 165

4. The table above shows the totals for the green and purple plants in our class as a
whole.
Table 5: Chi-square Equations and Results for Section 6 Data
Purple-stemmed Plants Green-stemmed Plants
Observed (o) 130 165
Expected (e) 221.25 73.75
Deviation (o – e) or d -91.25 91.25
Deviation2 (d2) 8326.56 8326.56
d2/e 37.63 112.9
Chi-square: Χ2=Σ (d2/e) =150.74
Table 6: Chi-square Equations and Results for Total Sample Data
Purple-stemmed Plants Green-stemmed Plants
Observed (o) 3113 1445
Expected (e) 3418.5 1139.5
Deviation (o – e) or d -305.5 305.5
Deviation2 (d2) 93330.25 93330.25
d2/e 27.3 81.9
Chi-square: Χ2=Σ (d2/e) =109.20
Aggregate Data
Table 7
Section # Purple-stemmed Plants Green-stemmed Plants
1 79 28
2 213 101
3 49 61
5 85 33
6 130 165
7 51 22

5. 8 8 3
9 181 82
10 154 71
11 83 31
12 62 24
13 104 35
14 1102 468
15 15 18
17 64 53
19 201 33
21 180 71
22 170 73
24 182 73
TOTALS: 3,113 1,445
Conclusion
Overall, the results were inconclusive due to many errors that simply did not refute nor support
the hypothesis. The hypothesis stated, the presence of purple pigment (anthocyanin) is inherited
as a dominant trait and follows Mendelian laws. According to table 4 above, which was the class
data, it expressed a ratio of 130:165 green stemmed plants being dominant. According to table 7,
which was all the gen bio sections, the purple stemmed plants were dominant with a 3,113:1,445
ratio. So, it seemed as though in the class (section 3) the green-stemmed purple trait was
dominant versus the purple, refuting our hypothesis. Also, according to all the section’s data
combined the purple-stemmed trait was dominant, supporting the hypothesis. Then, using the
data from tables 6 and 7 it proves that the green-stemmed plants would produce more versus the
purple-stemmed plants. Overall, due to the data supporting and refuting the hypothesis, this lead

6. to in conclusion. Some errors could be simply to fact that the F1 plants were not pollinated
correctly leading to inaccurate crossed between the F1 plants. Also, one of the most common
errors occurred was the counting of each phenotype on day 42. This could have led the results in
a complete different direction due a simple counting error. The hypothesis was supported by
some of the data collected and refuted as well, leaving an inconclusive result.
In future replications of this experiment many things can be improved. For example, each
class after planting the seeds on the first day should be more actively involved in the growth of
the plant and keep a close eye. The class did not really spend much time neither planting nor
monitoring the plants which could have led to the neglect to the plants. If future gen bio labs are
more actively involved then this could limit the amount of errors, leaving a clear conclusion.