Unit 1 – An Introduction to Biology

Q: What is Biology?

A: Biology is the Study of Life Q: What is Biology? A: Biology is the Study of Life

Branches of Science Related to Biology Anatomy – the study of an organisms parts Bacteriology – the study of bacteria Botany – the study of plants Ecology – the study of organisms and their relationship with their environment Genetics – the study of genes and heredity Herpetology – the study of reptiles

Branches of Science Related to Biology Cont'd Microbiology – the study microorganisms Physiology – the study of what body parts do (functions) Taxonomy - the study of classification Zoology – the study of animals

Q: What is the Scientific Method? A: A set of directions that scientists use to solve problems.

Step 1 – Define the Problem

Step 2 – Create a Hypothesis

Step 3 – Experiment (tests the hypothesis) +

Parts of an Experiment Variables – The part(s) of an experiment that changes. Controls – The part(s) of an experiment that doesn't change (good for comparing).

The plates below contain human cells with MRSA The plates below contain human cells with MRSA. Plates 1,2&3 are treated with drugs A,B&C. Plate 4 is not changed in any way. Sample Experiment

Sample Experiment Cont'd After 5 days, the plates are observed. 50% of the cells in plate 1 have died. 10% of the cells in plate 2 have died. 75% of the cells in plate 3 have died. In plate 4, 50% of the cells have died. What happened and why was plate 4 needed?

Step 4 – Observe the Results (gather data) or

Step 5 – Anaylze the Results and Draw Conclusions =

Step 6 – Record Your Work In science, it is often useful to keep a record of what you did, so you don't repeat experiments, can see patterns and a wide variety of other reasons.

Q: All living things share 7 characteristics. What are they?

1. All living things must use energy.

2. All living things must grow.

3. All living things must reproduce.

4. All living things must respond to stimuli (changes).

5. All living things have a definite form and limited size.

6. All living things change over a long period of time.

7. All living things have a limited lifespan.

Microscopes Microscopes are special tools scientists use to view small objects Magnification – how large you can make something appear Resolution – how clear the magnified image appears (image quality)

Types of Microscopes Compound Light – uses light and more than one lens to form an image Objects viewed must be thin enough for light to pass through them Can view living creatures Maximum magnification is about 2,000X

Types of Microscopes Cont'd Scanning Electron Microscope – uses a beam of electrons to create an image Gives incredible detail of surface structures Object being viewed is dead (sprayed with gasseous metal) Maximum magnification is about 50,000X

Types of Microscopes Cont'd Transmission Electron Microscope – uses a beam of electrons to create an image Only dead objects may be viewed (object must be thin enough for electrons to pass through it) Gives great detail of internal structures Maximum magnification power is about 2,000,000X

Parts of a Compound Light Microscope

Part 1 Base – gives the microscope support Also one of the parts you hold onto when carrying the microscope

Part 2 Light Source – provides the light that passes through the object being viewed Usually, this is an electric light, but in older microscopes, it may be a mirror

Part 3 Diaphragm – allows you to adjust the amount of light being used to view an object

Part 4 Stage – the part that the object being viewed is placed upon

Part 5 Stage Clips – hold slides in place

Parts 6&7 Objectives Lenses – lenses that allow you to change the magnification power used to view an object

Part 8 Revolving Nosepiece – rotates to allow you to change the objective lens being used

Part 9 Arm – supports the upper parts of the microscope Also, it is the second structure used to properly hold and carry a microscope

Part 10 Fine Adjustment Knob – used to fine focus the image you are viewing

Part 11 Body Tube – a structure that allows light to pass through it and spaces the lenses apart so a clear image can be viewed

Part 12 Coarse Adjustment Knob – begins the focusing process Brings the image close to being clearly in focus

Part 13 Eyepiece or Ocular – the lens that you look through at the top of a microscope Usually, they have a magnification power of 10X