Biology Forums - Study Force

1) Identify the type of mutation and how it would affect the protein made (amino acid) if the following changes occurred in the DNA template strand. (4 marks)

DNA Strand:  TCT AAC TAT CCC CTA

Third codon change from TAT to TAG.
Second codon change from AAC to ATC.
Nucleotide with adenine (A) base inserted between 14th and 15th nucleotide.
Ninth nucleotide changes from T to C.






2) SEE FIRST PHOTO ATTACHED TO ANSWER BOTH QUESTIONS
mRNA and tRNA are involved in producing proteins from genes in the DNA. One codon consisting of 3 nucleotides corresponds to an amino acid in the protein that gets built. It is important to understand the relationship between the following nucleic acids:


DNA template and mRNA strands are Answer
 
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DNA template and tRNA anticodon strands are Answer
 
.


DNA non-template and mRNA strands are Answer
 
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DNA non-template and tRNA anticodon strands are Answer
 
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DNA template and DNA non-template strands are Answer
 
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mRNA and tRNA anticodon strands are Answer

#1

Types of mutation Change in amino acids

1. Same sense No change in amino acid

(Both code for isoleucine)

2. Nonsense Leucine to no amino acid

3. Frameshift No change in amino acid

(Both code for aspartic acid)

4. Missense Isoleucine to methionine

Explanation: Substitution of a nucleotide is called point mutation. If same amino acid is encoded by the codon, this mutation is called same sense mutation. If the point mutation leads to creation of stop codon (UAA, UAG, UGA), it is called nonsense mutation. If a nucleotide is added in the original nucleotide chain leading to alteration of codons thereby changing the amino acids after that point of nucleotide addition, this mutation is called frameshift mutation. On the other hand, if the point mutation leads to a change in the amino acid encoded by that codon this muation is called missense mutation ( Isoleucine to methionine).

#2

DNA sense strand (aka non -template strand) and mRNA have the same nucleotide sequence. as well as DNA antisence strand (aka template strand) and tRNA have the same nucleotide sequence.

DNA sense strand (aka non -template strand) and DNA antisence strand (aka template strand) are complementary to each other. mRNA codon and tRNA anticodon are complementary to each other. Also DNA antisence strand (aka template strand) and mRNA are complementary to each other.

thanks for your help but i think question 2 you have to fill up the table as well i attached the photo thanks if you could help me with that