The following DNA sequence is a simulated gene taken from ✓ Solved

The following DNA sequence is a simulated gene taken from fish scales. It codes for a pigment, a molecule that causes the scale to have color. Follow the steps of gene expression to discover what color fish your DNA came from.

DNA: T A C G C T G T G G G A T A G A A A C G C A G T G T A A T C

  1. Transcribe the DNA sequence above into a messenger RNA.

  2. Translate the gene by filling in which amino acid each tRNA will drop off. This string of amino acids can then be folded into a pigment protein. On the next page, you will see the codes for each pigment found in fish scales.

  3. Based on your protein, what color was your fish?

PIGMENTS

  • Red: Met Arg His Ser Glu Ala Cys Ser Asp

  • Blue: Met Arg His Ser Glu Val Pro Arg Tyr

  • Green: Met Arg His Ser Glu Val Pro Gly Tyr

  • Silver: Met Arg His Pro Ile Phe Thr Trp Cys

  • Gold: Met Arg His Pro Ile Phe Ala Pro His

  • Bronze: Met Arg His Pro Ile Phe Ala Ser His

Now, we will imagine several different mutations happen to the gene and figure out what effect they have. For each mutation, transcribe the mRNA and translate it into amino acids. The mutated nucleotides are indicated by being underlined.

Mutation 1 DNA: T A C G C T G T G G G A T A G A A A C G C G G T G T A A T C

mRNA: _________________________________________________________________________

What color is a fish with this mutation?

Mutation 2 DNA: T A C G C T G T G G G T T A G A A A C G C A G T G T A A T C

mRNA: _________________________________________________________________________

What color is a fish with this mutation?

Mutation 3 DNA: T A C A C T G T G G G A T A G A A A C G C A G T G T A A T C

mRNA: _________________________________________________________________________

What happens as a result of this mutation? What might a fish with this mutation look like? If we added or removed a letter, how would that affect the protein produced by a gene?

Paper For Above Instructions

The provided DNA sequence represents a segment of a gene typically involved in pigment production, found in fish scales. This transcribed DNA can elucidate the type of fish and its color based on the resulting proteins.

1. Transcription of the DNA Sequence

The initial step in gene expression is transcription, where the DNA sequence is converted to messenger RNA (mRNA). The transcription process involves replacing thymine (T) with uracil (U) when converting from DNA to RNA.

For the provided DNA sequence: T A C G C T G T G G G A T A G A A A C G C A G T G T A A T C, the transcription will result in the following mRNA sequence:

mRNA: A U G C G A C A C C C U A U C U U U G C G U C A C A U U A G

2. Translation of the mRNA to Amino Acids

Next, the mRNA is translated into a chain of amino acids, which will eventually fold into a functional protein. Here, we will use the genetic code to determine the corresponding amino acids.

Using codons derived from the mRNA sequence:

  • AUG - Met

  • CGA - Arg

  • CAC - His

  • CCU - Pro

  • AUC - Ile

  • UUU - Phe

  • GCG - Ala

This results in the amino acid sequence: Met-Arg-His-Pro-Ile-Phe-Ala. Based on the pigment chart provided:

The resulting pigment corresponds to the amino acid sequence and would fall under the 'Red' category (Met Arg His Ser Glu Ala Cys Ser Asp).

3. Determining the Color of the Fish

Based on the amino acid sequence determined from the transcription and translation process, the fish derived from the simulated gene would likely be red in color.

Mutation Analysis

Next, we will explore the impact of specific mutations on the resultant mRNA and resulting protein.

Mutation 1

DNA: T A C G C T G T G G G A T A G A A A C G C G G T G T A A T C

Transcribing the mutated DNA sequence gives: mRNA: A U G C G A C A C C C U A U C U U U G C G C C A C A U U A G

Translating the mRNA yields: Met Arg His Pro Ile Phe Ala. Thus, a fish with this mutation would likely still be red.

Mutation 2

DNA: T A C G C T G T G G G T T A G A A A C G C A G T G T A A T C

Transcribed mRNA: A U G C G A C A C C C A A U C U U U G C G U C A C A U U A G

This translates to: Met Arg His Thr Leu Phe. A fish with this mutation might be green based on the pigment chart.

Mutation 3

DNA: T A C A C T G T G G G A T A G A A A C G C A G T G T A A T C

Resulting mRNA transcription: A U G U G A C A C C C U A U C U U U G C G U C A C A U U A G

This translates to: Met Trp His Pro Ile Phe. The mutations alter the protein significantly; the fish could appear different based on the specific mutation affecting the pigment.

Conclusion

Understanding DNA involves comprehending its transcription into mRNA and the translation to proteins, which dictate characteristics such as color. The analysis shows how mutations can lead to variability in appearance, crucial for adaptation in wild populations.

References

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