Germination Methodology, Lab Report Example

Research Question

How do varying levels of salt concentration in water (0%, 0.0625%, 0.125%, 0.25%, 0.5%) within the germination environment of the Broad bean and Mung bean affect the rate of germination within a period of 7 days?

Qualitative Data

Qualitative data will be recorded through observation of the seeds condition with special attention towards the emergence of radicles and other structures that define germination and growth over a 7 day period.

Quantitative Data

The quantitative data will be based on qualitative observations and include the percentage of the seeds germinated each day over 7 days, the mean germination time for each salt concentration in days, and the mean length of the newly germinated plant for each salt concentration at the end of the 7th day.

Independent Variables

The salinity of the germination will be controlled by addition of different salinity concentrations of the water to the germination environments of different plants. The salinities that will be used are listed below:

• 00%
• 0625%
• 125%
• 25%
• 0.50%

Controlled Variable

• Temperature: Enzymes typically operate only at ideal temperatures. Therefore, the enzymes in the seeds will be kept at optimum temperature to ensure activity. Cold temperature or very hot temperatures will prevent the seeds from germinating. The temperature of the water will be kept at a constant room temperature of 21 ± 0.5? and the temperature of the surroundings at a constant temperature of 22 ± 0.5?. These temperatures will be controlled by the fume cupboard where the experiment will take place and the temperature will be measured each day in the same room and location of each plant and water environment.
• Same amount of minerals and nutrients: Each plant was allowed the same amount of minerals and nutrients in the water because these can speed up or slow down the germination process and future growth of a plant. This was controlled by ensuring that water was retrieved from the same source at the same time. If it is necessary to retrieve water from different water sources at one point in the experiment, it is essential to perform of an analysis of the initial water being used by using pool test strips and comparing this data to readings of the pool tests strips on the new water source. If they have similar mineral levels, they can be approved for use.
• pH of the solutions: Water should be taken from the same source initially and the pH of the solutions added to each beaker should be of pH7, which can be determined using a pH meter. To increase the acidity of the water, HCl should be added until the pH reads 7. To increase the basicity of the water, NaoH should be added until the pH reads 7.
• Light: Many seeds require light for germination, including the Mung bean and Broad bean plants that will be investigated in this experiment. However, it is essential that the light is not too strong because this could have a negative impact the germination of the seeds. The light will be controlled in the fume cupboard and lamps will shine directed from the above so once the seeds are germinated, they would be able to make their own energy using photosynthesis and grow. To ensure that the amount of light available to the plants is ideal, experimental conditions will attempt to mimic the light available to them in their natural outdoor environment. To test this to ensure our own lamps would be acceptable for this purpose, a control study should be done. One bean will be placed near a well-lit window and only water with 0% salinity will be allowed in its germination environment. A second bean will be allowed to be germinated under the same conditions near the fume cupboard, only with the artificial light. After 7 days have passed, the growth of the two plants will be measured. If the growth of the two plants are comparable, it will be assumed that the indoor lighting is adequate enough to allow for usual plant growth. If this is not the case, this control experiment should be repeated until the ideal amount of indoor light to be used is found.
• Same seeds of two species should be used: This will ensure that there is the same rate of germination. It would be even better to ensure that the seeds used for each species of bean were retrieved from the same mother plant because their genetics will be similar. 15 seeds for each salt concentration should be used to more accurate and precise results.
• Amount of water added: The same volume of water was added to each beaker once daily, although the concentration of salinity of each water sample varies according to plant. The volume that will be used is 20 ± 0.5ml. Water should be added on the same time of the day as well as the measurements. A piece of paper tracking the information will be left next to each plant to ensure that the protocol was followed properly.
• Equal distance between each seed: The seeds will be distributed equally around the circumference of the beaker. The distance between each seed should be measured with a ruler of 3 ± 0.1cm and using a rope string make sure the seeds are evenly distributed. This will ensure that each bean has equal access to nutrition, and will not outgrow the others on this basis.

Uncontrolled Variable

• Carbon Dioxide and Oxygen concentration:  Carbon dioxide and oxygen concentration is essential for aerobic respiration and independent energy production. While this concentration cannot be controlled, the room where the experiment is going to take place will be constantly supplied with oxygen and carbon dioxide from the open window. Therefore, even though the precise amount of carbon dioxide and oxygen cannot be controlled, it is likely that each plant will receive an equal amount throughout the experiment.
• Viability of the Seeds: The seeds will be taken out of a packet and it is therefore difficult to know if they are going to be viable because their source is unknown. While it would be preferable to only use seeds that have a known origin, this may not be possible depending upon where the seeds are obtained. To bypass this potential issue, 15 trials for each salt concentration will be done and the mean and standard deviation will be calculated. The standard deviation can be used to determine if the results retrieved were too variable and if the experiment needs to be repeated on this basis.

Risk Assessment

No dangerous chemicals are used in this experiment, however hands should be carefully washed before and after the experiment. All the seeds should be handled carefully to avoid any damage which could affect the results. However, a laboratory coat and safety goggles will be used throughout the process to ensure safety against unpredictable events.

Preparing Salt Concentrations

Table 1: Amount of salt needed to prepare the right salt concentrations

To prepare these concentrations, it is useful to set up a proportion. Since percentages are numbers over 100, and the total volume used in each example was 250 ml, the following calculations were performed:

• 0/100 = x/250, where x is equal to 0 g
• .0625/100 = x/250, where x is equal to .16 g
• .125/100 = x/250, where x is equal to .31 g
• .25/100 = x/250, where x is equal to .63
• .5/100 = x/250, where x is equal to 1.25

1. Wear a lab coat and a pair of safety googles before proceeding.
2. Place the weighing boat onto the electronic balance and press the ‘zero’ button to make sure the weight of the weighing boat is not recorded. Using the spatula add the right amount of salt on to the weighing boat and make sure the weight matches the one on the right side of Table 1.
3. Measure out 250 ± 2 ml of tap water using a 250ml measuring cylinder and a plastic pipette to make sure the bottom of the meniscus is at a 250ml reading on the cylinder. Although a deviation of 2 ml is allowed, it is preferable to obtain an exact reading of 250 ml and this should be attempted.
4. Add the salt and the measured 250ml of tap water into the 250ml beaker, make sure no salt is left on the weighing boat. Mix using the stirring rod to make sure all the salt dissolves through fully. Hold up to the light to ensure that there are no residual particles floating in the water.
5. Label the beaker with the percentage of salt concentration with the marker pen.
6. Rinse the measuring cylinder and a plastic pipette through fully.
7. Repeat steps 1-5 for each salt concentration in Table 1.

Germination Method

1. Wear a lab coat and a pair of safety googles before setting up the experiment.
2. Use dry paper towels to roll and place accurately into each beaker as shown on photograph 4 (on the next page). Make sure each paper towel is at the very bottom and touches the sides of the beaker.
3. Using random sampling, pick 15 Broad beans out of a packet. For statistical purposes, it would be ideal to conduct the random sampling from a bean packet that contains at least 100 seeds. Using a ruler and a rope string, place the beans at the distance of 3cm from each other around the circumference of each beaker. Using a spatula adjust the position of the beans.
4. Using a 25ml measuring cylinder measure 20ml of prepared concentration, make sure the bottom of the meniscus is on the 20ml reading. Use the thermometer to measure the temperature of the solution and record it.
5. Using a plastic pipette use 10ml of the prepared concentration to sprinkle onto the paper towel in each beaker, make sure the bottom of the paper towel is soaked in the solution.
6. Fold a paper towel into a square and put in the middle of the bottom of each beaker and use the remaining 10ml to soak it with the solution.
7. Label each beaker using a marker pen with the salt concentration used and place all the beakers into the fume cupboard.
8. Wash the 25ml measuring cylinder.
9. Repeat steps 2-8 for each salt concentration with the Broad beans.
10. Repeat steps 2-8 for each salt concentration using the Mung beans instead of Broad beans.
11. Turn the light in the fume cupboard on but do not close the doors of the fume cupboard to provide oxygen and carbon dioxide in (Photograph 4 on the next page).
12. Using a string and a ruler, measure the length of germinated seeds each day at the same time. Count the number of seeds germinated of each species in each salt concentration and record the data.
13. After recording the data, use a 25cm measuring cylinder to measure out 20cm of specific solution and with a plastic pipette sprinkle onto the paper towel inside the beakers.