Genetics Original Gene Sequence: 3'-T AC CC Essay

Genetics

Original Gene Sequence: 3'-T AC CC T. TT AGTAGCCAC T-5

Transcription of Original: 3'-A UG GG A AA UCAUCGGUG A-5'

Translation of Original: Start codon Met, Gly, Asn, His, Arg, Stop

Mutated Gene Sequence 1: 3'-T ACGCT TT AGTAGCCAT T-5'

Transcription of Mutated 1: 3'-A UGCGA AA UCAUCGGUA A-5'

Translation of Mutated 1: Start codon Met, Arg, Asn, His, Arg, Stop

Mutated Gene Sequence 2: 3'-T AACCT TT ACTAGGCAC T-5'

Transcription of Mutated 2: 3'-AUUGGAAAUGAUCCGUGA

Translation of Mutated 2: Ile, Gly, Asn, Asp, Pro, Stop

The first and last codons of the sequences are the start and stop codons respectively. The start codon indicates where transcription should begin. The stop codon indicates where transcription should end.

When a mutation occurs in the start codon, transcription will not be initiated and thus a protein will not be produced. When a mutation in the stop codon occurs sometimes the mutation will still encode for a stop codon as was the case with mutated gene sequence 1 above. However, if the mutation does not code for a stop codon then transcription will continue causing the transcript to be incorrect for a particular protein and the resulting amino acid sequence will not produce a functional protein.3. Mutated gene sequence 1 does encode for a different protein than the original gene sequence. Amino acid glycine in the original sequence is replaced by arginine in the mutated gene sequence. Since mutated gene sequence 2 does not include a start codon transcription will not be initiated therefore no protein will be produced.

4. The amino acid sequence is important because it allows the protein to fold a particular way. A functional protein must have the proper structure. For example, a mutation that replaces a cysteine with another amino acid may knock out a critical cysteine bond in the folding of the protein so that it will not have a functional structure.

Part II:

1. Cystic Fibrosis:

C

c

C

CC

Cc

c

Cc

cc

2. There is a 25% chance that the child will be healthy and not a carrier of the cystic fibrosis trait indicated by the CC alleles. There is a 50% chance that the….....