DNA - Chromosomes

Mutations:

1) XYY - Supermale

Characteristics:

Y carries androgen, will be naturally more aggressive, violent

2) XXY - Klinefelter

3) XXX - Superfemale

Characteristics:

Extra X is suppressed.

4) XO - Turner

Notes:

No 4 chromosomes. Body naturally aborts.

All mutations have IQ less than normal.

The older you are, the higher chance of mutation.

Will the offspring of people with mutations also have mutations?

Most of the people with mutations will not be able to give birth.

Blood Identification Practical: Test 3

The 3rd test was the Kastle-Meyer Reagent (Reduced phenolphthalein kept in alkaline solution in the presence of zinc) test. Oxidation with haemoglobin and hydrogen peroxide will cause the colourless Kastle-Meyer Reagent to turn pink.

After adding Kastle-Meyer Reagent. Sample 4 is on the right, Sample 5 left.

It is observed that the centre of Sample 4 turns pink.

TADA. Sample 4 is the blood sample! Case closed.

Blood Identification Practical: Test 2

Test 2 was the luminol test. The iron present in blood catalyzes the chemical reaction that leads to the luminescence of the blood.

The one on the left is Sample 5, the one of the right is Sample 6 and of course the one at the top is Sample 4.

As you can see in the photo, Sample 4 glowed the brightest, but Sample 6 also glowed for a brief period of time. Sample 5 did not glow.

After adding the luminol. The luminol test narrowed down the possible samples of blood to Samples 4 & 6.

Blood Identification Practical: Test 1

Yesterday, we had a blood identification practical, in which we were given 6 substances to test. The substances provided were chili sauce, tomato sauce, fruit juice, dyes and real blood. The tests we used were 1. the hydrogen peroxide test, 2. the luminol test and 3. the kastle-meyer reagent test.These are the 6 substances, labeled 1, 2, 3, 4, 5 and 6. Actually, just by the appearance of the substances, we are able to eliminate some as possible blood samples. Sample 1 is actually very pink and looks like a dye, Sample 2 smells like tomato juice, Sample 3 is tinged orange, like some kind of syrup, Sample 4...looks like blood, Sample 5 looks like a purple dye and Sample 6 is quite diluted and particles are suspended in the liquid, much like watermelon juice.
After adding the hydrogen peroxide. I forgot to take a before, oops. The picture isn't very clear but Samples 4, 5 and 6 are bubbling at different degrees, and as such test positive for catalase. Sample 4 is the most bubbly followed by 5 and 6.

This is sample 4. After adding the hydrogen peroxide, it resembled foam.

This is Sample 5. It foamed for a short while and then became like this. It was purple before and became brown after adding hydrogen peroxide.

This is substance 6. It did not react until about 5 minutes later, when bubbles appeared within the liquid.

This is Janelle and Biqing's hydrogen peroxide test. They were experimenting with mixing two samples together and adding a large amount of hydrogen peroxide.

This actually looks good enough to eat, which is a little disturbing when you know that it might be blood (this is Samples 4 and 6 combined, if I'm not wrong.)

DNA;

Blood splatter patterns -- HOW it happened

Analysis of blood and other fluids -- WHO did it

Sources of DNA:

- Sweat

- Skin,

- Blood,

- Tissue,

- Mucus,

- Ear Wax,

- Saliva,

- Urine,

- Hair

- Semen

- Fingernails

etc.

The power of DNA evidence lies in statistics.

1. From cells to chromosomes to DNA and traits

2. Karyotyping

3. DNA Extraction

4. DNA Fingerprinting

DNA consists of C, T, A, G, phosphates and sugar

Who murdered Robert Hughes? (Long overdue!)

Rough Notes;

Facts about the Murder;

Victim: Robert Hughes

- middle-aged caucasian male

- break in followed by struggle

- hughes flaunted wealth, philandering

- motive could be jealousy

- cool autumn morning

- two diff women coming in and out of victim’s house at diff times in afternoon of murder

- One: pretty blonde at 1.00, good mood at 2.00, never seen before

- Two: feisty redhead, 4.00, stormed out 4: 15 mins later, seen before

- Strange man walking back and forth 10.15 pm on night of murder

Clues;

1. Blood splatter

- messy death

- 2 puncture wounds, carotid artery (neck) / heart, great loss of blood

- lost consciousness

- 2nd wound at heart

- The attacker must be as tall as victim, at least 5’9’

- suspect has been in many fights

- Murder weapon was a switchblade, narrow, 4 inches, good quality

2. Footprint

• men’s size 11 doc martin boot, drags his feet

1. 3. Tool Marks

• crowbar

• Guy that was walking around is electrician Bright Lights R us

4. Hair

• 5 hairs
• 2 brown, 1 red (short), 2 dyed blonde (long)

5. Fingerprints

• fingerprints on vase belong to pat the rat, convicted twice, electrician

6. Fibres

• 50% wool, 50% polyester, black, sweater

7. Time of Death

• dead for over 12 hours, 10.30 at night

8. Blood in Sink

• blood belongs to a woman

Answer;

Clues:

Footprint

Paint

Physical ‘crime tool’

Blood

Fibre

Wood

Hair

Document

Time of Death

Wound

DNA fingerprint

Field

Forensic Scientist

Morphology

Entomologist

Pathologist

Coroner

Fingerprinting;

Body Measurement:

- Head

- Arm spam

- Mainly bones, places with less flesh (more accurate)

Types of fingerprints:

- Visible

- Latent

- Impressed

Methods:

- Patent (can be seen)

- Latent (cannot be seen)

- Porous

- Non porous

Examples;

- Plastic

- Iodine

- Paper

The Mystery; The Awareness Test; The Exchange Principle

The Trash Tosser Mystery.

Things I noted:

- fishbone (criminal eats fish)

- Raccoon eats fish (is an omnivore)

- Bull does not eat fish (herbivore)

- Trashbag has an assortment of foodstuffs (criminal eats many things, may be a scavenger)

- Bull is well dressed, Raccoon is not?

Answer:

Raccoon is the criminal as it is an omnivore, unlike the Bull.

Evidence; the fishbone.

The Awareness Test.

How many tosses were there?

Answer: 13.

But did you see the moonwalking bear?

No! :O

Reflection of what you have learnt about yourself from the test.

I found that I’m not really aware of my surroundings, especially when focusing on a specific object. In a bid to count the number of passes, I did not see the moonwalking bear and only saw a black blur move across the screen. I did not pay much attention to it, which is rather strange as surely a moonwalking bear would command a certain amount of attention and would be hard to miss. Hence, I can conclude that we are in fact not very aware of the happenings around us and even the most attention-grabbing things can go unnoticed.

The Exchange Principle.

Every contact leaves a trace.