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Three different mutated bacteria, X, Y and Z were studied - Scottish Highers Biology - Question 2 - 2019
Question 2
Three different mutated bacteria, X, Y and Z were studied. Each had a mutation in a different region of its DNA that is transcribed to rRNA. Protein synthesis was m... show full transcript
Worked Solution & Example Answer:Three different mutated bacteria, X, Y and Z were studied - Scottish Highers Biology - Question 2 - 2019
Step 1
Calculate the simplest whole number ratio of percentage protein synthesis in cultures X, Y and Z.
Answer
To calculate the simplest whole number ratio of protein synthesis in cultures X, Y, and Z, we start by noting the respective percentages:
- X: 9%
- Y: 15%
- Z: 90%
Next, we convert these values to the smallest whole numbers by dividing each by the smallest value, which is 9:
- For X: ( \frac{9}{9} = 1 )
- For Y: ( \frac{15}{9} \approx 1.67 ) which rounds to 5 (when multiplied by 3 to have whole numbers)
- For Z: ( \frac{90}{9} = 10 )
Therefore, the simplest whole number ratio is: 1: (5):10. This can be expressed in the simplest form as: 1 : 5 : 30.
Step 2
Step 3
Using your knowledge of biology, suggest how a change in the sequence of bases in DNA transcribed to rRNA in the mutated cultures resulted in a decrease in protein synthesis.
Answer
A change in the sequence of bases in DNA that is transcribed to rRNA can lead to alterations in the structure or function of the ribosome. This may result in ribosomes that are not properly formed or functional, preventing effective translation. Consequently, if the ribosome is impaired, it will be less capable of binding to mRNA, which inhibits translation and leads to a reduction in protein synthesis.
Step 4
Describe one structural difference between DNA and rRNA.
Answer
One structural difference between DNA and rRNA is that DNA is double-stranded, while rRNA is single-stranded. Additionally, DNA contains the sugar deoxyribose and the base thymine, whereas rRNA contains ribose and uracil instead of thymine.