Introduction to biology LIFE – WHAT A BEAUTIFUL GIFT

biology Biology is the study of living things.

Cells Cells are living matter enclosed in a barrier (cell membrane).

Unicellular vs. multicellular organisms Unicellular organisms have only one cell type. Example: many types of bacteria Multicellular organisms have more than one cell type. Example: humans

8 characteristics of all living matter 1. Cells 2. Reproduction 3. Growth 4. Genetic Code 5. Energy 6. Respond 7. Stability 8. Change

Reproduction The process of producing new cells.

Growth Some organisms simply grow in size, while others actually develop.

Genetic code The DNA of an organism.

energy Materials an organism needs to survive.

respond Organisms respond to internal and external stimuli.

stability Organisms maintain an internally stable environment called homeostasis.

change The way an organism naturally evolves or adapts over time.

Levels of organization in the body 1. Cells 2. Tissues 3. Organs 4. Organ Systems

Cells Organelles – tiny organs inside of cells.

Tissues – groups of cells

Organs- group of tissues

Organ systems – groups of organs

Famous biologists

Aristotle Aristotle believed that life could be produced out of air or nothing. This phenomenon was called Spontaneous Generation. He was one of the first philosophers to be curious about life and where it came from.

Andreas vesalius In 1543, Andreas Vesalius published De Humini Corporus, which was the first accurate and detailed study human anatomy.

William harvey In 1628, William Harvey became the first scholar to describe the human heart. He showed how the blood pumped through the body, returns to the heart and is re- circulated.

Anton van Leeuwenhoek In 1673, Anton van Leeuwenhoek perfected the simple microscope. He observed cells and microorganisms.

Charles darwin In 1859, Darwin published On the Origin of Species, stating his Theory of Evolution.

James Watson and Francis Crick In 1953, James Watson and Francis Crick determined the structure of DNA, the Double Helix.

The Human Genome Project In 2000, Francis Collins and Craig Ventor announced their working copy of the Human Genome.

Gregor Mendel Father of Genetics

HISTORY OF BIOLOGY

Franscesco Redi EXPERIMENT ON SPONTANEOUS GENERATION HE WANTED TO PROVE THAT LIFE COME FROM LIFE.

Franscesco Redi EXPERIMENT ON SPONTANEOUS GENERATION TEST #1: JAR UNCOVERED WITH MEAT INSIDE RESULT: MAGGOTS APPEARED TEST #2: COVERED JAR WITH MEAT INSIDE RESULT: NO MAGGOTS APPEARED

Redi -Spontaneous Generation Experiment

Conclusion Redi determined that the flies laying eggs caused the maggots to appear, not spontaneous generation.

John Needham’S EXPERIMENT TO ATTACK REDI’S EXPERIMENT BELIEVED SPONTANEOUS GENERATION COULD OCCUR UNDER CERTAIN CONDITIONS.

John Needham’S EXPERIMENT TO ATTACK REDI’S EXPERIMENT TEST: SEALED A BOTTLE OF GRAVY AND HEATED IT TO KILL THE ORGANISMS RESULT: MICROORGANISMS APPEARED IN THE SEALED BOTTLE. CONCLUSION: SPONTANEOUS GENERATION CAN OCCUR UNDER THE RIGHT CONDITIONS.

Needham’s experiment

LAZARRO SPALLANZANI’S TEST TO SUPPORT REDI AND IMPROVE NEEDHAM’S WORK SPALLANZANI BELIEVED NEEDHAM DID NOT HEAT UP THE BOTTLE LONG ENOUG TO KILL THE MICROORGANISMS

LAZARRO SPALLANZANI’S TEST TO SUPPORT REDI AND IMPROVE NEEDHAM’S WORK TEST #1: GRAVY BOILED WITH OPEN FLASK RESULT: MICROORGANISMS APPEARED TEST #2: GRAVY BOILED WITH CLOSED FLASK RESULT: NO MICROOGANISMS CONCLUSION: LIFE COMES FROM LIFE AND SPONTANEOUS GENERATION DOES NOT EXIST

Spallanzani’s Experiment

Louis pasteur’s test of spontaneous generation Pasteur wanted to disprove Spontaneous Generation once and for all. Some people still believed that oxygen could produce life.

Louis pasteur’s test of spontaneous generation Test: Pasteur designed a flask with a long curved neck. Air could get into the flask but no microorgansisms. He boiled the broth. Results: No microorgansisms appeared. Conclusion: LIFE COMES LIFE

Pasteur’s Broth Experiment

Pasteur In 1881, Pasteur develops the first vaccine against anthrax. He invented the long neck flask. He also came up with the process of pasteurization.