Biology 101 Professor Ben Winslow Tue, Wed, Thur 9-12

Outline: -What is science and how is it done? -Scientific theories -Characteristics of life

What is science?

Correlation does not equal causation Marathon heart-attack deaths rise By Jack KellyPittsburgh Post- Gazette staffTue, 05/15/ :25pmJack KellyPittsburgh Post- Gazettestaff Runners suffered heart attacks in the Boston Marathon in April, the Myrtle Beach, S.C., Marathon in February, the New York and Philadelphia marathons last November and the Chicago Marathon last October. These incidents sparked renewed interest in possible links between distance running and heart failure.

What is a hypothesis? - A potential explanation of a natural phenomenon

Why is there an “ozone hole” in Antarctica? Hypothesis 1 - This observation is a freak weather event Hypothesis 2 - The ozone hole is caused by human activity

Why is there an “ozone hole” in Antarctica?

What is a scientific theory? - A basic statement that is supported by many observations and experiments

Cell theory -1600’s - Hooke looked at cork and identified cells -Shortly afterwards Leeuwenhoek observed many single celled organisms in pond water Schleiden and Schwann formalized “cell theory” -All living organisms are made of cells -All cells come from other cells

Theory of heredity -Genes are inherited from parent to offspring in discrete units (Mendel) -Chromosomal theory of inheritance - Genes reside on chromosomes, which are physically inherited

Gene Theory -“Genes” are encoded in DNA -Genes encode for proteins and RNA that make up organisms

Theory of evolution by natural selection

Characteristics of life - Kingdoms 6 kingdoms 3 domains

Characteristics of life - Cellular

Characteristics of life - Metabolism All organisms require chemical energy

Characteristics of life - Homeostasis Homeostasis is the maintenance of a controlled internal environment

Characteristics of life - Growth -Cells grow by adding mass -Large cells divide into multiple smaller cells -Multicellular organisms grow by adding cells

Characteristics of life - Heredity - Offspring inherit chromosomes from their parent(s)

Life is hierarchical Molecular Organismal Ecological

Life is hierarchical Molecular Organismal Ecological