Dependent and Independent Variables

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Lab 1: Dependent and Independent Variables

Lab Results

Table 1: Average Yield for each seed variety at no, low, and high infestation levels (8 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
167.67
BT 456

None
190
183.2
184.8
186

Low
178.8
172.6
179.6
177

High
157.3
157.0
159.0
157.76
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
137.76
Super Harvest

None
164.1
164.3
161.9
163.43

Low
159.1
155.0
157.5
157.2

High
125.5
129.0
130.0
128.16

Table 2: % Reduction in yield for each seed variety at high levels of infestation (4 points) (transfer data on average yield with no infestation and high infestation from Table 1 to Table 2) Seed Variety

Avg. Yield with
No Infestation
Avg. Yield with High Infestation
% Reduction
In Yield
BT 123

163.03
160.67
1.5%
BT 456

186
157.76
15%
Golden

184.73
137.76
25%
Super Harvest

163.43
128.16
22%

Laboratory Analysis Questions

1.ECB refers to: (1 pt)
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

2.How many days are required for a corn seed to become a mature plant with maximum weight kernels ready to be harvested? (1 pt) a.about 23
b.about 65
c.about 140
d.about 180

3.“BT Corn” refers to corn that: (1 pt)
a.Has been infested with insect pests
b.Has been infected with bacteria
c.Is resistant to ECB
d.Is not affected by pesticides

4.BT is: (1 pt)
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

5.Creation of BT corn requires genetic material from all of the following except: (1 pt) a.European corn borer
b.Bacillus thuringiensis
c.a corn plant
d.all of the above contribute genetic material to the production of BT corn

6.For each seed variety, why did you need to collect data from 3 pots for each infestation level to obtain reliable data? (2 pts)
To get accurate results we need to test the experiment more than once.

7.What is an independent variable? Which variable in this experiment was the independent variable? What is a dependent variable? Which variable in this experiment was the dependent variable? (2 pts)

The independent variable is the variable representing the value being manipulated or changed and the dependent variable is the observed result of the independent variable being manipulated. In the experiment the level of ECB infestation is the independent variable and the dependant variable is the yield of the corn plants in term of kernel weight per ear of corn.

8.Which seed variety has the highest yield under conditions of no infestation? (1 pt)
BT 456

9.Which transgenic seed variety was most resistant to the ECB at high infestation levels? (1 pt) BT 123

10.Which non-transgenic seed variety was most resistant to the ECB at high infestation levels? (1 pt) Golden Crop

11.Compare the yield of Super Harvest seeds and BT 123 seeds under conditions of no infestation. Is there any difference in the avg. yield? (2 pts)
Yes, a very miniscule difference is there. 0.4

11. 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. (2 pts) He should plant the golden crop for the remaining 10%. They have a larger yield than the...
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