5 page Lab Report must show statistical calculations similar to the showing in old work
INTRODUCTIONseedlings. This experiment forms the basis of your major assignment due later in semester. The peas in the experiment have a genetic mutation that means they produce little or no GA3, a hormone that influences lengthening of the stem during growth. The experiment will test whether adding GA3 in a solution overcomes the effect of this mutation. You will harvest the experiment in Lab 4, when your demonstrators will discuss how to go about writing the report.
length of one individual of one species and relate their structure to their functions.
METHODS- Experiment set-up: The effect of the hormone gibberellic acid on growth of dwarf peas.
The class will work together to set up this experiment.
Collect 20 dwarf pea seedlings. Number them 1 to 20 and label them as such.
Divide them into two groups of 10. Pots 1-10 will be treated with a solution containing deionized water and gibberellic acid. Pots 11-20 will be a control, and will be given only deionized water. (i.e. no GA3).
Measure the height of every seedling from the base to the stem apex (tip). Your demonstrator will help you find these points and to not mistake the tip of a tendril for the stem apex. Record the plant heights in millimetres in Table 4.1.
Place the pots in the sink for the next step. Measure out and pour 100 mL of deionised water into the sand in the pot of each control plant. Set the control seedlings aside.
Pour 100 mL of the GA3 solution (which contains only GA3 and DI water) onto the sand in the pot of each treatment seedling.
The plants will receive these treatments plus basic other nutrients twice weekly until you measure them again in two weeks’ time.
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This week you will complete the experiment you set up in Prac 3. Recall that dwarf peas have a genetic mutation that predisposes them to remain much shorter than normal peas. The mutation reduces the production of a hormone called gibberellic acid (GA3), which normally induces the stem to lengthen. A lack of gibberellin means the stems remain short in comparison to normal pea plants of the same age.
This experiment explores whether it is possible to overcome the genetic mutation by providing the dwarf plants with GA3 from an external source.
METHODSGather together the plants used in the experiment, and separate them into their two treatments.
Start with the plants that received the GA3 treatment. Measure their final heights in the same way that you measured in week 3. Enter the final heights in the relevant column of Table 4.1. Make sure that you match the final heights of each plant to the correct measurement of initial height i.e. in the same individual.
Repeat the procedure for the plants in the control treatment, but enter their heights in the appropriate columns in Table 4.2.
Using the Tables 4.1 and 4.2, calculate the change in height of each plant over the two weeks’ growth. It is these changes in height that are the data of interest in this experiment!
Calculate the mean and variance for each of the two treatments following the instructions below and using Tables 4.1 and 4.2.
Table 4.1 Calculations for GA3 treated dwarf pea plants
| A | B | C | D | E |
| Plant | Final height (mm) | Initial height (mm) | Change in height (mm) (x1, subtract C from B) | x12 D*D |
| 360 | 83 | |||
| 400 | 110 | |||
| 140 | 73 | |||
| 130 | 60 | |||
| 310 | 82 | |||
| 170 | 68 | |||
| 200 | 74 | |||
| 180 | 67 | |||
| 320 | 87 | |||
| 10 | 235 | 90 | ||
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