# Biology Ia Design

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• Topic: Standard deviation, Light, Arithmetic mean
• Pages : 6 (2130 words )
• Published : May 20, 2013

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Biology Internal Assessment: Beetroot Juice

Hypothesis: As the temperature of the beetroot increases, the percentage of blue light shone through the mixture will be lower because more red pigments will pass through the membrane

Raw Data for experiment:
Quantitative Data- Since this experiment is done in a large group, I did the experiment with a temperature of 40 ˚C. | | Percentage of light that passes through the mixture (%)| Groups| Temperature (C°) ±0.5| Reading 1| Reading 2| Reading 3| Reading 4| Reading 5| A| 8.0| 90.6| 97.7| 92.6| 95.0| 90.5|

B| 30.0| 96.0| 100.0| 97.9| 100.0| 97.9|
C| 40.0| 50.6| 66.5| 51.2| 80.0| 75.6|
D| 55.0| 8.2| 19.5| 16.1| 17.9| 18.1|
E| 70.0| 3.4| 2.7| 4.7| 3.0| 0.8|

Qualitative Data-
Temperature ±0.5/C°| Observations| Colour of mixture|
8.0| Faint pink| |
30.0| Light Pink| |
40.0| Pink| |
55.0| Light red| |
70.0| Dark red| |

This table shows; as the temperature gets higher the colour darkens.

Process Data for experiment:
| | Percentage of blue light that passes through the mixture (%)| | | Groups| Temperature (˚C) ±0.5| Reading 1| Reading 2| Reading 3| Reading 4| Reading 5| Average of all readings| Standard Deviation| A| 8.0| 90.6| 97.7| 92.6| 95.0| 90.5| 93.3| 3.1|

B| 30.0| 96.0| 100.0| 97.9| 100.0| 97.9| 98.4| 1.7| C| 40.0| 50.6| 66.5| 51.2| 80.0| 75.6| 64.8| 13.6| D| 55.0| 8.2| 19.5| 16.1| 17.9| 18.1| 16.0| 4.5|
E| 70.0| 3.4| 2.7| 4.7| 3.0| 0.8| 2.9| 1.4|

How to calculate Average- Add up all the results for a certain temperature and divide it by the number of recordings you have. In this case average temperature for 8 C° is calculated by 90.6+97.7+92.6+95.0+90.55=93.3 C°

How to calculate standard deviation- Standard deviation means how accurate or how close your results are, while compared to each other in the same set of recordings. First you should calculate the mean for the set of values, then subtract the mean with each values of the set, square the values and add them all together. After that, you divide the final value with the total amount of readings in one set minus one and then root the value you have. In this case, standard deviation for 8 C° is calculated by90.6+97.7+92.6+95.0+90.55=93.3 C°, (93.3-90.6)2+(93.3-97.7)2……=9.4675, 9.4675-1=3.1

Processed Data presentation-

*Error bars are represented as standard deviation.
*The point at 30˚C is an anomaly, it will be mentioned in the conclusion and evaluation.

Conclusion:
There is a clear pattern shown in the graph while the temperature decreases the percentage of blue light transmitted through the mixture increases. This means that if the temperature is low (around 10˚C), the mixture will be a faint (almost transparent) colour because less colour pigments are released into the water. And as temperature is high (around 40˚C), the colour of the mixture will be darker than the one where the temperature is at 10˚C.Therefore a small amount of light will be able to transmit through the solution. When the temperature is at 8 ˚C and its transmission of blue light is 93.3% because it is a faint (light and transparent) colour. But at temperatures of 40 C° and 70 C°, the transmission were 64.8% and 2.9%, this shows a gradual decrease in percentage of transmission. This proves the point that the colours of the mixtures darken as temperature increases, making it hard to transmit light through the mixture. Why would the colour darken as the temperature increases?

As it mentioned in the Aim, the purpose of this experiment is to see the effect of temperature on cell membranes and how it relates to membrane structure. Every molecule is made out of particles linked together with bonds, which affects the strength of the molecule as a whole. While we increase the temperature, each particle will vibrate or move in a faster speed, which leads to bonds breaking, this...