Lab Report

Topics: Hypothesis, Gregor Mendel, Ratio Pages: 6 (996 words) Published: March 25, 2014
﻿Lab Report
Background Information
The study of genetics and inheritance is concerned with understanding the biological properties that are passed on from parents to their offspring. By studying genetics and inheritance, plants and animals have progressed biologically which means they are more productive and in cases, have more nutrients. Also, humans who are parents can also get counseling about many human inheritable diseases. This lab experiment is about studying the inheritance of Zea Mays kernel color and texture similar to the one Gregor Mendel performed in his experiments on heredity in corn seed color and seed shape. Mendel also had a strong background in mathematics and he applied a statistical test to determine the validity of the data collected. Method:

1. Get the first maize
2. Observe a particular mark/pattern ( ie. A seed that got ripped off the maize) and remember it- This ensures that the same maize is not used twice 3. Count the seeds in columns- Count the yellow seeds first and then the purple 4. After counting one color record the data on a spreadsheet so there is no confusion 5. Repeat steps 2-4 for all 5 maize’s

Data Collection
1st Maize:

2nd Maize:

3rd Maize:

4th Maize:

5th Maize:

Images

Table 1- Number of Seeds Counted on Monohybrid Corn
Maize
# of Yellow Seeds
# of Purple Seeds
Total # of Seeds
1
152
542
694
2
118
438
556
3
136
510
646
4
106
409
515
5
126
475
601
Total
3012

Null Hypothesis:
The expected ratio for purple to yellow seeds in a maize are 3:1. After performing the experiment, the observed ratio is also 3:1 as shown below. Calculations
Sum of Seeds:

Ratios:
Maize 1:
Purple = (524/694) x 100= 78
Yellow = (152/694) x 100= 22
Ratio= 3:1
Maize 2:
Purple = (438/556) x 100= 78
Yellow = (118/556) x 100= 21
Ratio= 3:1
Maize 3:
Purple = (510/646) x 100= 78
Yellow = (136/646) x 100= 21
Ratio= 3:1
Maize 4:
Purple = (409/515) x 100 = 79
Yellow = (106/515) x 100= 21
Ratio= 3:1
Maize 5:
Purple = (475/601) x 100= 79
Yellow = (126/601) x 100= 21
Ratio= 3:1
Chi Squared Calculation:
x²= Ʃ(Observed Result – Expected Result)²/Expected Result 1. Expected Result = 3012/5= 602.4
2. Observed Result – Expected Result:
694-602.4 = 91.6
556-602.4 = -46.4
646-602.4 =43.6
515-602.4 =-87.4
601-602.4 =-1.4
3. (Observed – Expected)²
91.6²= 8391
-46.4²= 2153
43.6²= 1901
-87.4²= 7639
-1.4²= 2
4. (Observed-Expected)²/Expected
8391/602.4= 14
2153/602.4= 4
1901/602.4= 3
7639/602.4= 13
2/602.4=0.0003
5. Ʃ(Observed- Expected)²/ Expected
= 34.0003
Reject H0
Standard Deviation:

Observations:
While performing this experiment, a few observations that I made were that it was important to make sure that I did not use the same maize twice. The students who conducted the same monohybrid experiment that I did came up with a method. We would swap maize’s with each other, so when I was done I would give my maize to a classmate and receive one from another classmate. This way each person receives a different maize each time. To further ensure that I didn’t receive the same maize twice, I would always remember a particular mark or a pattern on the maize so that I’ll know if I get it again. I also observed that there are more purple seeds than yellow seeds in monohybrid maize. In fact in all cases, the ratio was exactly 3:1. Table 2- Number of Seeds Counted on a Monohybrid Corn

Maize
# of Yellow Seeds
# of Purple Seeds
1
152
542
2
118
438
3
136
510
4
106
409
5
126
475

Graph: Number of Seeds Counted on a Monohybrid Corn

Conclusion:
As shown on the graph above, it is shown that the purple seeds are greater than the yellow seeds. After calculating, the result was that the ratios were exactly 3:1 like expected before the...

Bibliography: Farrand, Al. "Mendelian Inheritance in Corn." Inheritance. Bellevue College Life Science, n.d. Web. 27 Feb. 2014.