Lab #1: Dependent and Independent Variables Worksheet
(Worth 120 possible points)
1. ECB refers to:
a. A genetically engineered plant that is resistant to insect pests
b. Edible corn byproducts
c. An insect pest that reduces corn yield
d. European corn borer
e. c and d(Worth 5 possible points)
2. How many days are required for a corn seed to become a mature plant with maximum weight kernels ready to be harvested?
a. about 23
b. about 65
c. about 140d. about 180
(Worth 5 possible points)
3. “BT Corn” refers to corn that:
a. Has been infested with insect pests
b. Has been infected with bacteria
c. Is resistant to ECBd. Is not affected by pesticides
(Worth 5 possible points)
4. BT is:
a. A stomach poison produced by bacteria
b. A genetically engineered corn product
c. A bacterium carried by the European corn borer
d. A bacterium that has a gene for producing Cry proteins(Worth 5 possible points)
5. Creation of BT corn requires genetic material from all of the following except:
a. European corn borerb. Bacillus thuringiensis
c. a corn plant
d. all of the above contribute genetic material to the production of BT corn
(Worth 5 possible points)
Table 1: Average Yield for each seed variety at no, low, and high infestation levels
(Worth 48 possible points)
Seed Variety Level of ECB Infestation Pot 1
Yield Pot 2
Yield Pot 3
Yield Average
Yield
BT 123
None 160.1 164.8 164.2 163.03
Low 164.0 162.6 168.3 164.97
High 155.1 163.0 163.9 160.67
BT 456
None 190.0 183.2 184.8 186.00
Low 178.8 172.6
179.6 177.00
High 157.3 157.0 159.0 157.77
Golden
None 181.6 182.8 189.8 184.73
Low 177.9 171.2 170.6 173.23
High 135.4 139.6 138.3 137.77
Super Harvest
None 164.1 164.3 161.9 163.43
Low 159.1 155.0 157.5 157.20
High 125.5 129.0 130.0 128.17
Table 2: % Reduction in yield for each seed variety at high levels of infestation
(Transfer data on Average Yield (g) with No Infestation and High Infestation from Table 1 to Table 2)
(Worth 12 possible points)
Seed Variety Avg. Yield with
No Infestation Avg. Yield with High Infestation % Reduction
In Yield
BT 123
163.03 160.67 1.45%
BT 456
186.00 157.77 15.18%
Golden
184.73 137.77 25.42%
Super Harvest
163.43 128.17 21.58%
6. For each seed variety, why did you need to collect data from 3 pots for each infestation level to obtain reliable data?
IT IS IMPORTANT IN ANY EXPERIMENT TO COLLECT ALL APPLICABLE DATA TO VERIFY OR DISPROVE RESULTS.(Worth 5 possible points)
7. Which seed variety has the highest yield under conditions of no infestation?
BT 456(Worth 5 possible points)
8. Which transgenic seed variety was most resistant to the ECB at high infestation levels?
BT 123(Worth 5 possible points)
9. Which non-transgenic seed variety was most resistant to the ECB at high infestation levels?
SUPER HARVEST(Worth 5 possible points)
10. Compare the yield of Super Harvest seeds and BT 123 seeds under conditions of no infestation. Is there any significant difference in the average yield?
NO(Worth 5 possible points)
11. If you compared one pot of Super Harvest and one pot of BT 123 with no infestation, would you expect the yield of each pot to be within 0.5g? Explain your answer.
YES, BECAUSE THEIR AVERAGE YEILDS AT NO INFESTION WERE SO CLOSE. Questions number 6 and 11 are related. There is natural genetic variation of individuals within all populations. To control for that variation we take an average of a number of individuals from the population. Highs and lows due to natural variation are thus “smoothed” out. This fact then correlates perfectly with question number 11. The reason we would not expect a single pot of BT 123 and Super Harvest to be within 0.5 grams of one another is because that number is based on an average of pots , which as noted above controls for individual variation that could deviate from the average greatly. In other words, the average has “smoothed” over individual variation that could be a lot higher or lower than the average.(Worth 5 possible points)
12. A farmer decides to plant 90% of one field with BT 123 seeds and the remaining 10% of the field with a different seed variety. He hopes this will slow the evolutionary development of BT resistant insects. Which seed variety should he use the 10% of his field that is not planted with BT 123 seeds? Explain your answer.
THE FARMER SHOULD PLANT THE GOLDEN VARIETY DUE TO A HIGH YIELD DESPITE INVESTATION.(Worth 5 possible points)
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