Microscopy

Question 1

Why do police tape off a crime scene?

Answer 1

So that no one touches the evidence before forensics gets to it

Question 2

What is forensic science?

Answer 2

Forensic science is the study of materials and situations that relate to crime. Forensic scientists gather and study evidence so that it can be used in a court of law.

Question 3

What are microscopes used for?

Answer 3

To examine small bits of data. To small to see with the naked eye.

Question 4

What are microscopes used for?

Answer 4

To examine small bits of data. To small to see with the naked eye.

Question 5

What if a normal microscope is too small to see the evidence?

Answer 5

You have to use an electron microscope. These are very powerful microscopes that provide better magnification and resolution.

Question 6

Define magnification;

Answer 6

How many times bigger the image is compared to the object.

Question 7

Define resolution;

Answer 7

How clearly the microscope can distinguish two separate points.

Question 8

Define resolution;

Answer 8

How clearly the microscope can distinguish two separate points.

Question 9

Converting Units; A typical cotton fibre is 10 micrometres wide. Convert these;

1cm = mm

1mm = micrometres

8cm = mm

6mm = micrometres

3500 micrometres = cm

Answer 9

10 mm

1000 micrometres

80 mm

6000

micrometres

3.5 mm = 0.35 cm

Question 10

Microsope | Light | Electron
Radiation source electrons

up to 1000 x

Resolution small

Image black and white

Answer 10

Microsope | Light | Electron
Radiation source light electrons

Typical magnification up to 1000 x up to 1 000 000 x

Resolution small large

Image colour black and white

Question 11

Name (5) samples of what forensic scientists might anaylize.

What do they do with their anaylsis.

Answer 11

Hair
Fibres
Paint Flecks
Pollen Grains
Soil

Try to match these with whats on the suspect or victims clothes or body.

Question 12

Why are Pollen Grains useful?

Answer 12

Pollen grains come in differnt sizes, shapes and surface texture.A pollen sample can make evidence that a suspect was at the crimee scene.

Question 13

What’s useful about Clothes Fibres?

Answer 13

Clothes fibres can match a suspect to the crime scene or a suspect and a victims hair/clothes

Clothes fibres look very different under the microscope.

Question 14

State one difference between the apperence of cotten and wool fibres.

Answer 14

Wool is very seperate and rigid.

Cotten is smoother and closer together. Cotten also twists together.

Question 15

What’s the one downside to using this technique for evdence?

Answer 15

Even though it may confirm a suspect was there at th scene of the crime it doesn’t determine when.