Biology IA Exemplar: Comparing the effects of UVC radiation (253.7nm… | RevisionDojo

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IB Biology HL Internal Assessment Example

Comparing the effects of UVC radiation (253.7nm wavelength) and white light (600nm wavelength) as a control, on the growth rate of prokaryotic bacteria Escherichia Coli K-12 in absorbance values per hour, determined by measuring optical density OD600 of 15 samples (in arbitrary units, ±0.001) for each light at wavelength 600nm in a spectrophotometer (Vernier, SpectroVIS) at varying time intervals; 0h, 1h, 2h, 3h, 4h, 22h, 24h.HL

Official IB Result

IB Grade: 6

Criteria A: Research Design

5/6

Criteria StrandsPro

A.1Research question context

Excellent

A.2Methodological considerations

Moderate

A.3Methodology description

Good

Criteria Feedback

The student posed a focused, testable question with a clearly identified organism, treatment conditions, instrument, and time points.
The student placed the investigation in an appropriate biological and practical context by linking UVC exposure to DNA damage and sterilisation.
The student's method is detailed enough in many places that a reader could follow the overall investigation and reproduce much of it.

Some key parts of the setup are not explained with enough precision, especially how the actual light dose reaching the bacteria was ensured.
A few scientific choices weaken the design, such as treating OD600 as if it directly measured growth and not fully resolving the implications of the vessel material.
There are some inconsistencies and ambiguities in the procedure that reduce full reproducibility.

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

Poor

Criteria Feedback

The student recorded a substantial amount of raw data, summary statistics, and graphical output, so the reader can follow what was measured and how the results were processed.
The student showed awareness of uncertainty by using standard deviations, error bars, and noting practical issues such as spills and damaged equipment.
The student attempted quantitative comparison rather than stopping at descriptive observations alone.

The data processing is not always communicated with enough precision, especially where the calculation steps and formulas create confusion.
There are important validity problems in the analysis, including unclear blank correction, missing values, and a statistical test output that does not align cleanly with the raw data.
Some interpretations go beyond what OD600 can securely show, so the biological meaning of the numbers is overstated in places.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and consistency

Moderate

C.2Scientific context comparison

Moderate

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

6/6

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

5/6

Criteria StrandsPro

A.1Research question context

Excellent

A.2Methodological considerations

Moderate

A.3Methodology description

Good

Criteria Feedback

The student posed a focused, testable question with a clearly identified organism, treatment conditions, instrument, and time points.
The student placed the investigation in an appropriate biological and practical context by linking UVC exposure to DNA damage and sterilisation.
The student's method is detailed enough in many places that a reader could follow the overall investigation and reproduce much of it.

Some key parts of the setup are not explained with enough precision, especially how the actual light dose reaching the bacteria was ensured.
A few scientific choices weaken the design, such as treating OD600 as if it directly measured growth and not fully resolving the implications of the vessel material.
There are some inconsistencies and ambiguities in the procedure that reduce full reproducibility.

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

Poor

Criteria Feedback

The student recorded a substantial amount of raw data, summary statistics, and graphical output, so the reader can follow what was measured and how the results were processed.
The student showed awareness of uncertainty by using standard deviations, error bars, and noting practical issues such as spills and damaged equipment.
The student attempted quantitative comparison rather than stopping at descriptive observations alone.

The data processing is not always communicated with enough precision, especially where the calculation steps and formulas create confusion.
There are important validity problems in the analysis, including unclear blank correction, missing values, and a statistical test output that does not align cleanly with the raw data.
Some interpretations go beyond what OD600 can securely show, so the biological meaning of the numbers is overstated in places.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and consistency

Moderate

C.2Scientific context comparison

Moderate

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

6/6

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.