The document summarizes a student's biology research project investigating the effect of light exposure on mung bean germination. The student designed an experiment with five light exposure conditions (0, 2, 4, 6, 8 hours per day) and tracked germination rates over 72 hours. Results showed that mung beans receiving 8 hours of light germinated the fastest, with a statistically significant difference from the no light condition. However, differences between other light intervals were not statistically significant. The student concluded that increased light exposure facilitated faster germination by warming the beans and stimulating enzymes.

1. Alex Temple
HL Biology year 2
Period 5
IRP 3: Germination
Introduction:
Germination is the process of which a plant of fungus emerges from its seed
or spore. Germination involves activating the seed’s metabolism, which is done
through numerous stages. The fist stage involves the rehydrating the cell by
absorbing water. This allows the cell to become metabolically active. After water
absorption, gibberellin is produced in the cotyledon of the seed. The enzyme
gibberellin stimulates the production of amylase, which catalyzes the digestion of
starch and converts it into maltose in the food the seed stores. Maltose is then
transported to the growth regions of the seed. Maltose is converted into glucose,
which can either be used in the cell for aerobic cellular respiration or other
substances needed for growth. After the leaves of the seed are exposed to light,
photosynthesis provides the seed with food and the food stores are no longer
needed. In this research, the relationship between Mung bean light exposure and
germination will be investigated.
In order for germination to take place certain external factors are needed.
Water must be available for the seed to hydrate the dry tissues to activate the seed’s
metabolism. Oxygen must also be available for the cell to perform aerobic cellular
respiration. The environment the seed is germinating in must be in suitable
temperatures. Enzymes within the seed for germination is affected by temperature,

2. Alex Temple
HL Biology year 2
Period 5
if the temperature is too cold or hot, the process of germination may be slow or
impossible.
Design
Research Question: The affect of different hours of light exposure in the germination
of Mung Beans.
Variables:
The independent variables in this research include the different amount of
times Mung beans are exposed to light. The different amount of time involved with
light exposure for Mung beans consisted of two-hour intervals. The amounts of light
Mung beans were exposed to wear 0-2-4-6-8 hours of light within a period of 24
hours for three days.
The dependent variable within the research was the germination of the Mung
beans. The dependent variable was measured by counting the number of Mung
beans germinated within each 24-hour period and recorded as quantitative data,
qualitative data was also recorded as well.
The research was also conducted with controlled variables involved. The
control groups within the research were the trails not receiving any amount of light
at all. All Mung beans were exposed to the same light intensity and source. The
light source was a lamp placed at a distance of 24 centimeter above the petri dishes.

3. Alex Temple
HL Biology year 2
Period 5
The petri dishes were also left in the same location that had a constant room
temperature of 25 degrees Celsius. The same amount of water, 40 milliliters of
water was poured in each petri dish as well, coming from the same source.
Materials:
20 Petri Dishes
400 Mung Beans
Gradual Cylinder (100mls)
Water
2 Lamps
Cotton Buds
Meter Stick
Procedure:
The research involved setting up an environment for Mung beans to
germinate. Toured up pieces of cotton buds were placed in each petri dish to absorb
water, allowing the hydration of Mung beans. 20 Mung beans were placed in each
petri dished and 40 milliliters of water was distributed in each petri dish. After all
previous steps have been executed; place the petri dishes under the light source for
the desired amount of time. After the desired amount of time for petri dishes to be
exposed to light, remove them and place them in a location with no light source
available. After a span of 24-hours have passed since the Mung beans have be
exposed to light, place the petri dish back under the light source for the desired

4. Alex Temple
HL Biology year 2
Period 5
amount of time. This process was repeated for each trail three times within a span
of 72 hours.
Number of Germinations Within the First 24-Hour Period
Trials and Number of hours of light exposure
number of 0 hours 2 hours 4 hours 6 hours 8 hours
germinations
Trial 1 0/20 0/20 0/20 0/20 0/20
Trial 2 0/20 0/20 0/20 0/20 0/20
Trial 3 0/20 0/20 0/20 0/20 0/20
Average 0 0 0 0 0
number of
germinations
Table 1- the table above displays the number of germinations for each trial within
the first 24-hours.
Number of Germinations Within the First 48-Hour Period
Trials and Number of hours of light exposure
number of 0 hours 2 hours 4 hours 6 hours 8 hours
germinations (± 0.58) (± 1) (± 1.53) (± 1.73) (± 1)
Trial 1 7/20 7/20 8/20 10/20 11/20
Trial 2 8/20 9/20 9/20 10/20 12/20
Trial 3 8/20 8/20 10/20 13/20 13/20
Average 7.66 8 9 11 12
number of
germinations
Table 2- the table above displays the number of germinations for each trial within
the first 48-hours.

5. Alex Temple
HL Biology year 2
Period 5
Number of Germinations Over the Course of 72 Hours
Trials and Number of hours of light exposure
number of 0 hours 2 hours 4 hours 6 hours 8 hours
germinations (± 1.15) (± 0.58) (± 0.58) (± 1) (± 0.58)
Trial 1 16/20 16/20 17/20 20/20 20/20
Trial 2 18/20 15/20 17/20 18/20 20/20
Trial 3 16/20 16/20 18/20 19/20 18/20
Average 16.66 15.66 17.33 19 19.33
number of
germinations
Table 3- the table above displays the number of germinations for each trial within
72 hours.

6. Alex Temple
HL Biology year 2
Period 5
Hours Mung Beans Mung Beans Mung Beans Mung Beans Mung Beans
Receiving Receiving Receiving Receiving Receiving
No Light Two Hours Four Hours Six Hours of Eight Hours
of Light of Light Light of Light
After 24 Mung Beans Mung Beans Mung Beans Mung Beans Mung Beans
Hours have have have have have
hydrated hydrated hydrated hydrated hydrated
and and and and and
increased in increased in increased in increased in increased in
Size Size Size Size Size
After 48 Less than Less than Almost half More than More than
Hours half of the half of the of the Mung half of the half of the
Mung Beans Mung Beans Beans have Mung Beans Mung Beans
have have germinated have have
germinated germinated (27/60). germinated germinated
(23/60). (24/60). Seed coat (33/60). (36). Seed
Seed coat Seed coat has broken Seed coat coat has
has broken has broken and bean has broken broken and
and bean and bean shoot is and bean bean shoot
shoot is shoot is visible. shoot is is visible
visible. visible. visible and and has
has slightly extended
extended out.
out.
After 72 Most of the Most of the Most of the Most of the Most of the
Mung Beans Mung Beans Mung Beans Mung Beans Mung Beans
(50/60) (47/60) (52/60) (57/60) (58/60)
have have have have have
germinated. germinated. germinated. germinated. germinated.
The seed The seed The seed The seed The seed
coat has coat has coat has coat has coat has
been been been been been
broken broken broken broken broken
completely completely completely completely completely
and bean and bean and bean and bean and bean
shoots are shoots are shoots are shoots are shoots are
completely completely completely completely completely
visible, visible, visible, visible, visible,
along with along with along with along with along with
some roots. some roots. some roots. some roots. some roots.

7. Alex Temple
HL Biology year 2
Period 5
Graph1 – The graph above displays the total average Mung bean germinations for
each amount of light exposure over the course of 72 hours.
From conducting a t-test, the data collected was considered to be statistically
significant. The data used to conduct the t-test were for the trials of the Mung beans
receiving not light and eight hours of light after the course of 72 hours. This data
was used to determine whether light exposure had an affect on germination on not.
The p- value calculated was 0.3739, which showed determined statically significant
data. T-test where also conducted between each interval of two hours of light
exposure on Mung beans. The t-test determine the data to not be statistically
significant From using the data sets of Mung Beans receiving six hours of light
exposure and eight hours of light exposure after the end of forty-eight hour time
period, the p-value measured to be 0.2508, determining to be insignificant.

8. Alex Temple
HL Biology year 2
Period 5
T-test between Mung beans receiving no light and two hours of light after 72-hour
period.
P value and statistical significance:
The two-tailed P value equals 0.2508
By conventional criteria, this difference is considered to be not statistically
significant.
T-test between Mung beans receiving two hours of light and four hours of light after
72-hour period.
P value and statistical significance:
The two-tailed P value equals 0.0668
By conventional criteria, this difference is considered to be not quite statistically
significant.
T-test between Mung beans receiving four hours of light and eight hours of light
after 72-hour period.
P value and statistical significance:
The two-tailed P value equals 0.3739
By conventional criteria, this difference is considered to be not statistically
significant.

9. Alex Temple
HL Biology year 2
Period 5
T-test between Mung beans receiving four hours of light and eight hours of light
after 72-hour period.
P value and statistical significance:
The two-tailed P value equals 0.0158
By conventional criteria, this difference is considered to be statistically significant.
Sample Calculations:
Calculating the total average for Mung beans to germinate under specific amounts of
light exposure can be determined by using the following formula (trial 1+ trial 2+
trial 3)/3.
Sample calculation for Mung bean germination after receiving 6 hours of light in-
between 24-48 hours: (10+10+13)/3 = 11
Calculations for uncertainties can be determined by calculating the standard
deviation between two sets of data.
Calculating uncertainties can be conducted by calculating the range within a set of
data then dividing by two.
Sample calculation for Mung beans being exposed to light for six hours after a 72-
hour period. : (20-18)/2=1
Conclusion

10. Alex Temple
HL Biology year 2
Period 5
From examining the results of the research, Mung beans receiving eight
hours of light a day were able to germinate the fastest. The average calculated for all
germination trails within each 24-hour period for Mung beans exposed to eight
hours of light was always the greatest within the data set compared to Mung beans
exposed to light for 0,2,4,6 hours of light a day. The line graph clearly shows a
steady increase of germination of Mung beans receiving greater amounts of light
exposure. From examining tables 1,2,3; trials between two hours intervals were not
that significantly different but between Mung beans receiving no light exposure and
eight hours of light exposure, there was a significant difference. After the end of the
72-hour period, there was an average of 2.67 more germinations between Mung
beans receiving eight hours of light and Mung beans receiving no light.
Although the amount of germinations between Mung beans exposed to light
or not light was not drastic, the process of germination was still increased. The
reason behind germination occurring quicker may have been the change in
temperature of the Mung bean. Mung beans germinate faster in warm
environments due to the rate of enzyme activity. The enzyme gibberellin was able
to be stimulated quicker and produce amylase, which catalyzed the digestion of
starch and converted it into maltose in the food the seed stores, which enabled
maltose to be transported to the growth regions of the Mung beans, resulting in
germination.

11. Alex Temple
HL Biology year 2
Period 5
Evaluation
One random source of error could be potentially the distribution of water
and the Mung beans within each petri dish. Mung beans located close to each other
were unable to absorb water and hydrate as much as Mung beans given more space
between other Mung beans. This error could have been avoided by distributing less
Mung beans within each petri dish and using more trials instead. Water distribution
may have been another factor. Some Mung beans have received more water for
absorption and hydration than other Mung beans due to poor water distribution.
Another source of error may have been the placement of cotton buds. Some areas
within a petri dish may have been padded with cotton buds poorly, resulting in poor
absorption of water, which then would result in poor absorption for Mung beans.
The only way to avoid this error would to place cotton pads instead of ripped pieces
of cotton buds, this would ensure even cotton distribution for water absorption.