LABS, MICROSCOPES, AND OBSERVATION SKILLS

Glassware Safety

1. Never use broken glassware.

2. Never heat wet glassware.

3. Always wear heat-resistant gloves.

4. Always clean glassware thoroughly.

5. Always wear safety goggles.

Fire and Heat Safety

1. Always wear safety goggles.

2. Never heat without permission.

3. Never heat in a closed container.

4. Never reach across a flame.

5. Always use clamps, tongs, or heat-resistant gloves.

6. Always be clean.

7. Always know the locations of the fire extinguisher (in the back of the room) and fire blanket (in Mrs. Porter’s room).

Chemical Safety

1. Always waft and rinse chemicals.

2. Never mix chemicals without permission.

3. Never touch or taste chemicals.

4. Always close lids.

5. Always dispose correctly.

6. Always know the locations of the shower (Ms. Vargas’ room) and eyewash station (Mrs. Porter’s room).

Eye and Face Safety

1. Always wear safety goggles.

2. Always point test tubes and bottles away from people.

Sharp Instrument Safety

1. Always handle sharp objects with care.

2. Always cut away from people.

3. Always tell the teacher if someone is cut.

Electrical Safety

1. Never plug in more than one thing.

2. Never touch outlets or appliances with wet hands.

3. Always keep liquids away from outlets and appliances.

Animal Safety

1. Never hurt animals.

2. Always be humane with animals.

3. Always stay clean.

A beaker…

1. holds.

2. measures.

3. heats.

A test tube…

1. holds.

A microscope…

1. magnifies.

Latex gloves…

1. protect.

Forceps…

1. grab.

A thermometer…

1. measures

A pipette…

1. transfers.

A test tube rack…

1. holds.

Safety goggles…

1. protect

A magnifying glass…

1. magnifies

A petri dish…

1. cultures.

A microscope slide…

1. holds.

A coverslip…

1. protects.

A probe…

1. moves.

2. separates.

3. pins.

A graduated cylinder…

1. measures.

An eyepiece…

1. can also be known as the ocular lens.

2. is a place to view the specimen.

A course adjustment knob…

1. moves the stage up and down.

2. is used only with low and medium objective lenses.

A fine adjustment knob…

1. fines tunes the focus.

2. is used with all objective lenses.

Stage clips…

1. hold a slide in place on the stage for viewing.

A light source…

1. shines light upward through the specimen and to the lenses.

A nosepiece…

1. rotates to change between different objective lenses.

Objective lenses…

1. are three to four different lenses ranging from 4x-40x (4x, 10x, 40x).

A stage…

1. holds the slide and has a window that allows light to pass through the specimen.

A diaphragm…

1. turns to adjust the amount of light that passes through the specimen.

A compound light microscope uses … lenses?

two

Light passes through a sample, which creates an …?

image

The image is passed through an … lens first, then an eyepiece lens before reaching your ….

objective, eye

The two lenses work … to magnify the image so that it appears larger to your eye.

together

Calculating Magnification

1. 4x, 10x, 40x

2. 10x, 10x, 10x

3. 40x, 100x, 400x

Carry the microscope by the … and the ….

arm, base

Adjust the … to ensure light is passing through the specimen.

diaphragm

Clean the lens with … paper only.

lens

Return the … lens to low power when you are finished.

objective

Keep the microscope … when not in use.

covered

Don’t use the course adjustment knob with the … power lenses, for you could … the slide.

high, break

Don’t put specimens directly on the ….

stage

Don’t touch the microscope with your … or other objects.

hands

Keep the microscope ….

clean

Forensic investigators must rely on their ability to …, …, and … observations clearly.

observe, interpret, report

Examiners must be able to identify the evidence, record it, and determine its ….

significance

This is difficult, as human … is always a possibilty.

error

We are constantly gathering information about our ….

surroundings

The brain … this information, for it can’t hold all of the information that is observed on a daily basis.

filters

Paying attention to detail takes ….

conscious effort

Observations cannot be confused with ….

perceptions

Perceptions are made as a result of an ….

observation

Perceptions can be ….

faulty

How does the brain take observations and process them?

1. information from our senses

2. what we pay attention to

3. perceptions

4. short-term memory

5. long-term memory

Memory fades with … (long-term memory).

time

If you don’t use it, you’ll … it!

lose

The frontal lobe…

1. is associated with reasoning, planning, parts of speech, emotions, and problem solving.

The parietal lobe…

1. is associated with movement, orientation, recognition, and perception of stimuli.

The occipital lobe…

1. is associated with visual processing.

The temporal lobe (the auditory section)…

1. is associated with perception, memory, and speech.

Many times, investigators must rely on the observation skills of the … at a crime scene.

eye witnesses

How can an investigator be a good observer?

1. Make a conscious effort to examine the environment.

2. Observe everything slowly, or scan the scene.

3. Make connections to observations, or relate observations to prior knowledge.

4. Don’t jump to conclusions.

5. Photograph and take notes.

Once observations are made, a forensic investigator can use … to solve the crime.

deductive reasoning

What is deductive reasoning?

1. deriving the consequences from facts using a series of logical steps

2. starting from things you assume to be true and drawing conclusions that must be true if your assumptions are true

Why might deductive reasoning not be the most accurate way of solving a problem?

1. Assumptions can be wrong.