Fingerprints homework

I didn't bring a camera on that day! I even asked around but no one had a camera so there are no photos for the iodine activity and the microscopic view of the polymer cast of my fingerprint. WILL REMEMBER TO BRING MY CAMERA/HANDPHONE NEXT TIME BLEH D:

(Ridges and pores activity)

1. Where are the pores found? Are they regularly spaced?
The pores are found along the fingerprint ridges. They are quite regularly spaced.

2. Are the lines of your print equally spaced throughout?
Yes there are (sort of). The spaces are quite even but not exactly the same.

(Cyanoacrylate (Superglue) fuming method)

1. If the contrast of the white print against the black background is still too faint for a good detailed photograph to be captured, what could be done to enhance the fingerprint?
It is possible to treat it with fluorescent dye to make it glow under UV light.

(Iodine fuming method)

1. What are the possible substances that may be used to render the prints more permanent?
A solution of starch and water. This can make the fingerprint last for several weeks or months.

2. Why does the print disappear?
The print disappears because the iodine vapor can escape quickly (this is just a guess, can't find out actual reason)

(Powder dusting method)

1. What is magnetic powder dusting and how does it work?
Magnetic powder dusting is using powder to dust over the fingerprint so as to be able to see fingerprints. The powder is then lifted up using a sticky tape to preserve it. It works as the powder attaches to any greasy/oily substance in the fingerprint deposit.

O: This website has a lot about fingerprints and how it is used in forensics. It also has how different patterns of fingerprints are developed:

During early embryonic development (four to five weeks) there is swelling of (mesenchymal) tissue on areas of the sole, palm and digits. These areas are known as volar pads. The pads stop growing at about 10 weeks of development but the hand continues to grow. The volar pads are then absorbed back into the hand and as the pads shrink the skin folds to produce the ridges of fingerprints. The first ridges begin to appear at around 10 weeks.

Based on the pattern of pad absorption and timing, various combinations of fingerprint can occur:

If ridges appear when the volar pads are quite pronounced, the ridge pattern is a whorl.
If ridges appear when the volar pads are less pronounced, the ridge pattern is a loop.
If ridges appear when the volar pads are nearly absorbed, the ridge pattern is an arch.

... Does that mean that the patten shows the order in which your ridges form? Other than my thumbs, most of my fingerprints patterns are loops, meaning the ridges on my other fingers appeared first O: cool

Anyway, the next activity was a fingerprint database. We were supposed to submit the pattern of our thumbprint and then collate the data from 210 and 213 to plot a graph. I plotted 2 graphs, 1 of the number of people and one of the percentage of the people:



The graphs were similar to the ones Ms Tan plotted, seeing that the amount of people whose thumbprint patterns are arches < whorls < loops. The percentage was calculated to see the number in relevance to the population size, since the number of people in each class is different.

I'm not sure which "american data" I am supposed to, but the compared to this data:
Arches: 5%
Loops: 60-70%
Whorls: 25-35%
(taken from here)

the fingerprint patterns data we have shows a higher percentage of people with arches. This could be due to the fact that the data has a smaller sample size, thus higher inaccuracy.