Trouble in The Wheat Field Case Study – Mike Brown was a wheat farmer

Ontario Virtual High School Trouble in The Wheat Field Case Study

Assignment: Trouble In the Wheat Fields Case Study

Mike Brown was a wheat farmer with a reputation for having the best crops in the region. For decades, he sold his harvest for the highest price to the major companies in the industry. In recent years, Mike noticed that the neighbouring farm, operated by John Wilson, was producing bigger wheat plants.

 John, who recently took over his father’s farm, was a recent graduate of a university program in molecular biology. Mike often wondered why a scientist would be interested in farming. Mike had learned all he knew about farming from his father and grandfather; he did not understand how some young man who was interested in test tubes and Bunsen burners could possibly be better at growing wheat. Mike was determined that next year his crop would be best.

 The following harvest, Mike and John both produced tall golden wheat plants that were almost identical. John, who was using a special transgenic seed, was concerned that Mike had stolen his seeds. Early that spring, someone broke into John’s barn and stole a bag of his seed. Mike vehemently denied the theft, but John was extremely suspicious.

John, wanting to find out if his neighbour was growing his transgenic wheat plants, hired your laboratory to investigate the incident. John has provided you with one of his transgenic seeds, one of the non-transgenic seeds and a seed from Mike’s harvest this year.

Instructions

The table below contains short DNA sequences (36 nucleotides) obtained from the wheat seed John took from Mike’s farm. Complete Parts I and II described in the accordion panels. Upload your answers to the assignment questions to the appropriate Dropbox.

Allele (Copy) DNA Sequence

 Copy 1 Strand 1: ATGGTCGGCCATAGAGTGGGCCAGTACTTGAGGTAT Strand 2: TACCAGCCGGTATCTCACCCGGTCATGAACTCCATA

Copy 2 Strand 1: ATGGTCGGCCATAGAGTGGGTCAGTACTTGAGGTAT Strand 2: TACCAGCCGGTATCTCACCCAGTCATGAACTCCATA

Part I Cut both copies of the DNA sequence with the restriction endonuclease Hemophilius aegypticus (HaeIII).

 The restriction enzyme HaeIII recognizes the following four nucleotide sequence:

GG | CC CC | GG

HaeIII cuts the DNA strand between the guanine (G) and the cytosine (C).

1. Look at each of the two copies of the DNA sequence and identify how many times you find the restriction site (GGCC). Record the number of HaeIII sites in the table provided.

2. Once you have identified the number of restriction sites present in each sequence, determine the sizes of the DNA fragments you get when you cut the DNA with HaeIII. Add the fragments sizes to your table.

DNA Sequence Number of Restriction Sites DNA Fragme Sizes (# nucleot Allele Copy 1 Strand 1: ATGGTCGGCCATAGAGTGGGCCAGTACTTGAGGTAT Strand 2: TACCAGCCGGTATCTCACCCGGTCATGAACTCCATA Allele Copy 2 Strand 1: ATGGTCGGCCATAGAGTGGGTCAGTACTTGAGGTAT Strand 2: TACCAGCCGGTATCTCACCCAGTCATGAACTCCATA

Part II

Questions

Answer the questions below.

1. What conclusions can you draw from the RFLP analysis of the seed taken from Mike’s harvest tell you?

2. Do the results of the test prove that Mike stole the seed from John?

3. Explain how electrophoresis can separate DNA fragments based on size.

4. In an RFLP analysis, would using multiple restriction enzymes be beneficial to determining the genetic identity of an individual?

5. Research and discuss how one of the following is an example of polymorphism in humans:

a. Blood types

 b. Male and female sex types

Assessment Details

Your submission should include the following:

 ? Your answers to the questions written in your own words

 ? All in-text citations and a reference list according to the APA style guide for sources used in your submission

Upload your complete answers to the Assignment: Trouble in the Wheat Field Case Study Dropbox.