I. History

A. Spontaneous Generation (Abiogenesis)

1. 1st proposed by Aristotle

2. Believed that complex, living organisms are generated by decaying organic substances,

Example: mice would spontaneously appear in stored grain OR maggots would spontaneously appear in meat.

I. History (con’t)

A.Spontaneous Generation (Abiogenesis)

3. Was widely believed until the 19th century.

4. Several scientists performed experiments that disproved spontaneous generation

• Francisco Redi

• Lazzaro Spallanzani

• Louis Pasteur

The Characteristics Common to Life

Pasteur’s Experiment Proved Biogenesis

Louis Pasteur

1859

B. Biogenesis – all living organisms come from pre-existing living things.

- Anything that possesses the following characteristics of life is called an organism.

I. Common Characteristics of Life

A. Made of Cells – organized from the cell upB. Reproduction ( asexual or sexual)C. Grow and DevelopD. Adaptation to environmentE. Maintain HomeostasisF. Based on a universal molecular code (DNA)G. Obtain and use materials and energy (ATP)

A. Cells – The Basic Unit of Life

An Amazing Fact: THE HUMAN BODY … … is a collection of a trillion, diverse and

highly organized cells.

What does it takes to keep this collection of a trillion cells “alive” ? A combination of Biology … Chemistry …

Genetics … Physics …

C. Reproduction- All living organisms are able to reproduce themselves

Asexual – DNA from only 1 parent

Sexual – DNA combining from 2 parents

Binary Fissio

nSpore

Formation Hydra BuddingSperm

fertilizing egg

Asexual Sexual

C. Growth and Development Unicellular organism

Growth … an increase in the size of the cell Development … an increase in the # of

organelles in the cytoplasm

Multicellular organisms Growth ... An increase in the # of cells Development … Cells specialize / diversify

and form tissues, organs, and organ systems

D. Adaptation

All organisms are able to adapt to their surroundings ...

To be able to … respond to stimulus and react! Examples…?

E. Homeostasis

The ability of an organism to maintain a relatively constant internal environment that is suitable for the life of its cells.

Sweating…shivering…increased respiration…being thirsty … etc.

II. Tools of Science

A. Common Measurement System = SI“The Metric System”- based on a system of 10

Length – metersVolume – litersMass – gramsTemperature – centigrade

Prefixes added to the basic units above:milli = 1/1000 centi = 1/100 kilo – 1000

II. Tools of Bio-Sciences

B. Microscopes1. Light – compound microscopes

10X (eyepiece) 10X, 40X, objectives

2. Electron Microscopes TEM – transmission electron

microscope (detailed interior picture)

SEM – scanning electron microscope (detailed 3-D exterior pic.)

F. A Common Hereditary Thread DNA – the molecule that is common

to all living organisms Provides the code for making all the

diverse proteins necessary for cell life

III. Laboratory Techniques

Wet Mount Slide Adding a liquid to a dry specimen on a slide

and using a cover slip to protect liquid from microscope objectives

Cell Cultures Growing groups of cells from one parent cell

Cell Fractionation Separating and collecting only one part of a

cell

SI Measurements – prefix “ladder” 1,000,000 M mega

1,000 k kilo

100 h hecto

10 D decka

1 base units: meter, liter, or gram

.1 d deci

.01 c centi

.001 m milli

.0000001 micro

.0000000001 n nano

1 x 10-12 p pica