Biology IA Exemplar: In what ways does pH levels of 4.0, 5.0, 6.0,… | RevisionDojo

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IB Biology SL Internal Assessment Example

In what ways does pH levels of 4.0, 5.0, 6.0, 7.0, and 8.0 affect the catalytic rate of alpha-amylase enzyme derived from the bacterium Bacillus subtilis for complete hydrolysis of starch as the rate is experimentally defined by the iodine-potassium iodide test?SL

Official IB Result

IB Grade: 6

Criteria A: Research Design

4/6

Criteria StrandsPro

A.1Research question context

Excellent

A.2Methodological considerations

Good

A.3Methodology description

Moderate

Criteria Feedback

The student's research question is specific, operationalized, and clearly grounded in enzyme activity and pH.
The student defines the enzyme source, substrate, pH conditions, temperature, and endpoint method with enough detail to show a clear experimental focus.
The student shows good awareness that the bacterial enzyme is being used as a model rather than directly representing human salivary amylase.

The broader biological framing would be stronger if the distinction between the bacterial enzyme model and human digestion had been established more explicitly from the start.
Some methodological choices are described, but a few important controls and justifications are still only partly explained.
The procedure is not detailed enough in every step to remove ambiguity for another investigator.

Criteria B: Data Analysis

4/6

Criteria StrandsPro

B.1Communication of data recording and processing

Moderate

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Moderate

Criteria Feedback

The student's raw and processed data are organized clearly, making the pH trend easy to follow.
The student calculates means, spread, and reciprocal-time values in a systematic way.
The student makes a genuine attempt to treat variability and uncertainty quantitatively using repeats and error bars.

The terminology for the processed values is not always accurate, because the experiment measures an endpoint time rather than a true initial rate.
Some uncertainty handling is incomplete, especially where measurement and propagation issues are not carried through consistently.
Parts of the statistical processing contain internal inconsistencies, so some pairwise comparison results cannot be trusted as presented.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and consistency

Moderate

C.2Scientific context comparison

Poor

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Criteria D: Evaluation

3/6

Criteria StrandsPro

D.1Methodological weaknesses

Good

D.2Improvements

Good

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Loading scores...

Official IB Result

IB Grade: 6

Criteria A: Research Design

4/6

Criteria StrandsPro

A.1Research question context

Excellent

A.2Methodological considerations

Good

A.3Methodology description

Moderate

Criteria Feedback

The student's research question is specific, operationalized, and clearly grounded in enzyme activity and pH.
The student defines the enzyme source, substrate, pH conditions, temperature, and endpoint method with enough detail to show a clear experimental focus.
The student shows good awareness that the bacterial enzyme is being used as a model rather than directly representing human salivary amylase.

The broader biological framing would be stronger if the distinction between the bacterial enzyme model and human digestion had been established more explicitly from the start.
Some methodological choices are described, but a few important controls and justifications are still only partly explained.
The procedure is not detailed enough in every step to remove ambiguity for another investigator.

Criteria B: Data Analysis

4/6

Criteria StrandsPro

B.1Communication of data recording and processing

Moderate

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Moderate

Criteria Feedback

The student's raw and processed data are organized clearly, making the pH trend easy to follow.
The student calculates means, spread, and reciprocal-time values in a systematic way.
The student makes a genuine attempt to treat variability and uncertainty quantitatively using repeats and error bars.

The terminology for the processed values is not always accurate, because the experiment measures an endpoint time rather than a true initial rate.
Some uncertainty handling is incomplete, especially where measurement and propagation issues are not carried through consistently.
Parts of the statistical processing contain internal inconsistencies, so some pairwise comparison results cannot be trusted as presented.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and consistency

Moderate

C.2Scientific context comparison

Poor

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Criteria D: Evaluation

3/6

Criteria StrandsPro

D.1Methodological weaknesses

Good

D.2Improvements

Good

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.