Alex Temple HL Biology year 2 Period 5 IRP 3: GerminationIntroduction: Germination is the process of which a plant of fungus emerges from its seedor spore. Germination involves activating the seed’s metabolism, which is donethrough numerous stages. The fist stage involves the rehydrating the cell byabsorbing water. This allows the cell to become metabolically active. After waterabsorption, gibberellin is produced in the cotyledon of the seed. The enzymegibberellin stimulates the production of amylase, which catalyzes the digestion ofstarch and converts it into maltose in the food the seed stores. Maltose is thentransported 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 othersubstances 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 longerneeded. In this research, the relationship between Mung bean light exposure andgermination 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’smetabolism. Oxygen must also be available for the cell to perform aerobic cellularrespiration. The environment the seed is germinating in must be in suitabletemperatures. Enzymes within the seed for germination is affected by temperature,
Alex Temple HL Biology year 2 Period 5if the temperature is too cold or hot, the process of germination may be slow orimpossible.DesignResearch Question: The affect of different hours of light exposure in the germinationof Mung Beans.Variables: The independent variables in this research include the different amount oftimes Mung beans are exposed to light. The different amount of time involved withlight exposure for Mung beans consisted of two-hour intervals. The amounts of lightMung beans were exposed to wear 0-2-4-6-8 hours of light within a period of 24hours for three days. The dependent variable within the research was the germination of the Mungbeans. The dependent variable was measured by counting the number of Mungbeans 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. Thecontrol groups within the research were the trails not receiving any amount of lightat all. All Mung beans were exposed to the same light intensity and source. Thelight source was a lamp placed at a distance of 24 centimeter above the petri dishes.
Alex Temple HL Biology year 2 Period 5The petri dishes were also left in the same location that had a constant roomtemperature of 25 degrees Celsius. The same amount of water, 40 milliliters ofwater 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 StickProcedure: The research involved setting up an environment for Mung beans togerminate. Toured up pieces of cotton buds were placed in each petri dish to absorbwater, allowing the hydration of Mung beans. 20 Mung beans were placed in eachpetri dished and 40 milliliters of water was distributed in each petri dish. After allprevious steps have been executed; place the petri dishes under the light source forthe desired amount of time. After the desired amount of time for petri dishes to beexposed to light, remove them and place them in a location with no light sourceavailable. After a span of 24-hours have passed since the Mung beans have beexposed to light, place the petri dish back under the light source for the desired
Alex Temple HL Biology year 2 Period 5amount of time. This process was repeated for each trail three times within a spanof 72 hours.Number of Germinations Within the First 24-Hour PeriodTrials and Number of hours of light exposurenumber of 0 hours 2 hours 4 hours 6 hours 8 hoursgerminationsTrial 1 0/20 0/20 0/20 0/20 0/20Trial 2 0/20 0/20 0/20 0/20 0/20Trial 3 0/20 0/20 0/20 0/20 0/20Average 0 0 0 0 0number ofgerminationsTable 1- the table above displays the number of germinations for each trial withinthe first 24-hours.Number of Germinations Within the First 48-Hour PeriodTrials and Number of hours of light exposurenumber of 0 hours 2 hours 4 hours 6 hours 8 hoursgerminations (± 0.58) (± 1) (± 1.53) (± 1.73) (± 1)Trial 1 7/20 7/20 8/20 10/20 11/20Trial 2 8/20 9/20 9/20 10/20 12/20Trial 3 8/20 8/20 10/20 13/20 13/20Average 7.66 8 9 11 12number ofgerminationsTable 2- the table above displays the number of germinations for each trial withinthe first 48-hours.
Alex Temple HL Biology year 2 Period 5Number of Germinations Over the Course of 72 HoursTrials and Number of hours of light exposurenumber of 0 hours 2 hours 4 hours 6 hours 8 hoursgerminations (± 1.15) (± 0.58) (± 0.58) (± 1) (± 0.58)Trial 1 16/20 16/20 17/20 20/20 20/20Trial 2 18/20 15/20 17/20 18/20 20/20Trial 3 16/20 16/20 18/20 19/20 18/20Average 16.66 15.66 17.33 19 19.33number ofgerminationsTable 3- the table above displays the number of germinations for each trial within72 hours.
Alex Temple HL Biology year 2 Period 5Hours 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 LightAfter 24 Mung Beans Mung Beans Mung Beans Mung Beans Mung BeansHours 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 SizeAfter 48 Less than Less than Almost half More than More thanHours 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.
Alex Temple HL Biology year 2 Period 5Graph1 – The graph above displays the total average Mung bean germinations foreach amount of light exposure over the course of 72 hours.From conducting a t-test, the data collected was considered to be statisticallysignificant. The data used to conduct the t-test were for the trials of the Mung beansreceiving not light and eight hours of light after the course of 72 hours. This datawas used to determine whether light exposure had an affect on germination on not.The p- value calculated was 0.3739, which showed determined statically significantdata. T-test where also conducted between each interval of two hours of lightexposure on Mung beans. The t-test determine the data to not be statisticallysignificant From using the data sets of Mung Beans receiving six hours of lightexposure and eight hours of light exposure after the end of forty-eight hour timeperiod, the p-value measured to be 0.2508, determining to be insignificant.
Alex Temple HL Biology year 2 Period 5T-test between Mung beans receiving no light and two hours of light after 72-hourperiod.P value and statistical significance:The two-tailed P value equals 0.2508 By conventional criteria, this difference is considered to be not statisticallysignificant.T-test between Mung beans receiving two hours of light and four hours of light after72-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 statisticallysignificant.T-test between Mung beans receiving four hours of light and eight hours of lightafter 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 statisticallysignificant.
Alex Temple HL Biology year 2 Period 5T-test between Mung beans receiving four hours of light and eight hours of lightafter 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 oflight 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 = 11Calculations for uncertainties can be determined by calculating the standarddeviation between two sets of data.Calculating uncertainties can be conducted by calculating the range within a set ofdata then dividing by two.Sample calculation for Mung beans being exposed to light for six hours after a 72-hour period. : (20-18)/2=1Conclusion
Alex Temple HL Biology year 2 Period 5 From examining the results of the research, Mung beans receiving eighthours of light a day were able to germinate the fastest. The average calculated for allgermination trails within each 24-hour period for Mung beans exposed to eighthours of light was always the greatest within the data set compared to Mung beansexposed to light for 0,2,4,6 hours of light a day. The line graph clearly shows asteady increase of germination of Mung beans receiving greater amounts of lightexposure. From examining tables 1,2,3; trials between two hours intervals were notthat significantly different but between Mung beans receiving no light exposure andeight hours of light exposure, there was a significant difference. After the end of the72-hour period, there was an average of 2.67 more germinations between Mungbeans receiving eight hours of light and Mung beans receiving no light. Although the amount of germinations between Mung beans exposed to lightor not light was not drastic, the process of germination was still increased. Thereason behind germination occurring quicker may have been the change intemperature of the Mung bean. Mung beans germinate faster in warmenvironments due to the rate of enzyme activity. The enzyme gibberellin was ableto be stimulated quicker and produce amylase, which catalyzed the digestion ofstarch and converted it into maltose in the food the seed stores, which enabledmaltose to be transported to the growth regions of the Mung beans, resulting ingermination.
Alex Temple HL Biology year 2 Period 5Evaluation One random source of error could be potentially the distribution of waterand the Mung beans within each petri dish. Mung beans located close to each otherwere unable to absorb water and hydrate as much as Mung beans given more spacebetween other Mung beans. This error could have been avoided by distributing lessMung beans within each petri dish and using more trials instead. Water distributionmay have been another factor. Some Mung beans have received more water forabsorption and hydration than other Mung beans due to poor water distribution.Another source of error may have been the placement of cotton buds. Some areaswithin a petri dish may have been padded with cotton buds poorly, resulting in poorabsorption 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 piecesof cotton buds, this would ensure even cotton distribution for water absorption.