The Effect of Various pH Levels on Pinto Bean Germination Rate by

INTRODUCTION AND OBJECTIVE

atucker6 — 2015-10-05 20:21:14 UTC

In this experiment, pinto bean seeds were used to test the effect of various pH's on germination rate. Germination is the process in which a seed begins to grow. In order for a seed to germinate it must have a seed coat, adequate water, sun light and air. Later on in the germination process root support and soil is required. The first stage of germination is when the seed takes in water through the micropyle (small pore located on seed coat) and the seed coat begins to wear off because the inside is expanding with the water. Once the seed coat breaks the radicle (root) will emerge. The radicles will then begin to develop, a system of radicles will appear, the main root and the lateral system of radicles will be the plants source of stability and nutrients and root hairs will develop allowing the roots to accomplish this. Next the hypocotyl (stem) will emerge. The purpose of the hypocotyl is to carry the nutrients to the leaves and shoots of the plant. The final stage of germination is the appearance of leaves. The leaves function to provide plants with nutrients through the process of photosynthesis. Six weeks after the leaves appear the bean plant will begin to bud. In this experiment, germination rate was found by measuring the height of the beans (10) in each group, by cm on the third, fifth and seventh day of germination and then averaging the bean height together.

All rain contains a bit of acid therefore even diluted acids count as being acid rain. In the experiment we used a weak acid solution to represent the acid rain. Not all acids are very strong which is why in this experiment a diluted acid solution was used. Some acid rain around the world isn't quite so powerful so the solution used represents those parts of the world. For example New York has a pH of 4.3 which is a quite strong acid rain average. This is mainly because New York is largely populated causing lots of pollution in the air to form more acid rain. The diluted acid shows more of the states in the U.S. that have a small population density like Vermont or Wyoming. These states do not have as much transportation automobile fumes being let into the air which explains the higher scale of their pH levels.

This information is relevant in many ways to farmers, who make money on how much produce they grow for the markets. If the produce is larger then normal, they will make more money and be more successful. If some types of bean plants germination rate increase or decrease due to acidic rain, this information will help farmers decide which bean plants to grow depending on their region (how much pollution is present) and the region's pH level in the rain.

HYPOTHESIS

atucker6 — 2015-10-07 00:04:03 UTC

If acids with various pH’s are applied to pinto bean seeds, then the pinto bean seed germination rate will decrease as pH level decreases.

MATERIALS

atucker6 — 2015-10-07 00:05:34 UTC

-Pinto beans (60)

-Acetic acid stock solution

-test tubes (6)

-test tube rack

-pipets

-pH probe

-distilled water

-baggies (6)

-paper towels (6)

-graduated cylinder

-markers

-scissors

-camera

-kim wipes (5)

-labels (6)

-tape

-window

PROCEDURE

atucker6 — 2015-10-07 00:07:05 UTC

Follow the dilution of acids procedure in the Acid Rain and Seeds handout and create solutions. Collect all materials. Place six paper towels out on the desk. Cut the paper towels in half to make twelve pieces total and pair the halfs together (two per baggie). Pour a different test tube of acid on each paper towel set (2 halves), paper towels should be not op os each other. Place ten pinto beans on top of each paper towel set. Fold the paper towels in half covering the beans (hamburger style), fold once more and then place each paper towel set in a separate baggie. Label the baggie with the name of the solution. Hang the baggies on the window with tape. Place all baggies near each other to ensure that the beans will receive the same amount of sunlight. Take down each baggie of beans and measure each bean’s growth (height) with a ruler on the third, fifth and seventh day of germination. To measure the beans stretch out the radicle (once it germinates) and record data. Make sure to return the proper bean group to its proper baggie after measurement. Then for each group of beans average the height to determine the germination rate. Record all data and continue this process for three days. Measurement is taken for a total of one week, but is only measured on the third, fifth and seventh days. Form a conclusion based on results.

ANALYSIS

atucker6 — 2015-10-07 00:07:43 UTC

The purpose of this experiment was to test if different levels of pH affect acid rain. Each solution (independent variable) represented different levels of pH in acid rain. The stock solution had the highest acidity and the acidic level decreased through each solution (4X, 16X, 64X and 256X). The distilled water was a neutral with a pH of 7 and served as the control group which is required for comparison. The beans were placed in groups of ten in each bag for five days and observed. As seen in the graph, Germination Rate of Pinto Beans, the 4x solution had the highest germination rate (11.2 cm) and the 64x solution had the lowest germination rate (6.3. According to the graph, Germination Rate of Pinto Beans, the beans were able to sustain growth despite the pH's of each solution used to germinate the beans. The graph also revealed that there was no trend showing that pH either promoted or demoted growth because one of the lowest pH solutions and the neutral pH had the highest rate of germination. Refer to the data tables for the pH of each solution. The hypothesis was: If acids with various pH’s are applied to pinto bean seeds, then the pinto bean seed germination rate will decrease as pH level decreases. This hypothesis cannot be excepted because even though all solutions promoted growth of the pinto bean seeds, pH's had no clear impact upon pinto bean seeds. All the beans made it through germination, except two beans which rotted. As seen in the graph, Germination Rate of Pinto Beans, one of the highest pH's of solutions and one of the lowest pH's of solutions both had the top two germination rates. This suggests that the level of pH in each solution does not effect the germination rate of beans, though all solutions had growth, so the experiment should be repeated with more pinto beans (100 per group) tested to ensure results. Sources of error in this experiment could potentially be found in measurement of the beans. Beans may not have been stretched out long enough to obtain the full measurement which would change the germination rate of a set of beans. Another source of possible error may have been the amount of solution in each group of beans. The measurement of each solution could have been slightly off which would change the constant of amount of solution to a variable. The amount of solution, if changed from a constant to a variable, could affect the germination rate of beans as well as the measurement of the pinto beans. As seen in the data tables, no evidence of error was discovered. This project could be enhanced by taking more measurements each day of the week and add more pinto beans to each group. Another enhancement would be to measured over a longer period of time (three weeks). To ensure all data was accurate the experiment should be repeated multiple times. Other experiments could also help to further continue this study. For example, other plants could be tested to see if different types of plants are affected by different pH levels. An experiment that tested with a wider range of pH levels tested on beans or other plants could also continue to extend the study of various pH affects on beans.

Pinto Beans on the Window

atucker6 — 2015-10-07 00:19:10 UTC

Cole and Julia

Cole measuring height of Pinto Beans

atucker6 — 2015-10-07 00:43:38 UTC

Conclusion

jseeman — 2015-10-07 01:37:09 UTC

In the experiment the conclusion based on the data was that pinto beans are not greatly affected by the pH level (acid rain). The possible cause for this outcome would be that pinto beans have possibly adapted to acidic rain over the years. Each generation has a higher pH level in rain because pollution continues to increase through car and factory exhaust. Over the years plants have learned to adapt through natural selection and the beans used in this experiment were most likely adapted to acidic rain and thrived when germinated with all different kinds of pH levels. The data taken was thought to have been useful for farmers, but because the results were inconclusive it is not particularly helpful. PH does not have a noticeable affect on this generation's beans, so farmers should not be concerned about the destruction of their pinto bean plants to acidic rain.

Pinto Beans on the Window

atucker6 — 2015-10-07 02:30:38 UTC

Ariel

Graph

jseeman — 2015-10-07 19:59:46 UTC

Distilled Water Data Table

jseeman — 2015-10-07 20:01:03 UTC

pH level: 7

4x Data Table

jseeman — 2015-10-07 20:02:04 UTC

pH level: 4.6

16x Data Table

jseeman — 2015-10-07 20:02:38 UTC

pH level: 5.4

64x Data Table

jseeman — 2015-10-07 20:05:58 UTC

pH level: 5.6

256x Data Table

jseeman — 2015-10-07 20:07:52 UTC

pH level: 6.3

Stock Data Table

jseeman — 2015-10-07 20:08:46 UTC

pH level: 4.2