Bio notes section 1

Bio notes section 1 - Biology Notes Section 1: Lectures...

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Biology Notes Section 1: Lectures 1+2/ Chapter 1 What is science? – A way of knowing things; a body of knowledge accumulated through scientific investigation. How do we know things? – Scientific method: observation question hypotheses experiments (w/ the purpose of unequivocally rejecting hypothesis after hypothesis) conclusion. Theory: broad intellectual construct supported by factual evidence that has explanatory power. e.g. Cell theory (1830s): all living organisms are made of cells. - Natural selection is a theory evolution is a FACT; the “theory is evolution” is that it occurred through natural selection. 19 th c: Louis Pasteur’s classic experiment testing (and rejecting) the hypothesis of “spontaneous generation” - S-curve flask trapped environmental particles from entering the flask full of sterile broth. - In this case, no growth= evidence against spontaneous generation. - He then removed the S-curve trap to allow air/dust from outside to enter; led to growth. - And: tipped the flask to allow trapped dust to mix w/ brother; led to growth as well. Hierarchy of life: atom – molecule – cell – tissue – organ – organism – population – community – ecosystem – biosphere. Homeostasis: ability of an organism to self-maintain their internal environment. 3 major divisions of living things: 1. Prokaryotes – Bacteria : a. “Prokaryote” = before nucleus. b. Unicellular; have cell walls; most are heterotrophic; can be pathogenic. c. Scale: around 3 microns (1 micron – 1 one-thousandth of a millimeter) d. Three major shapes: spherical (cocci), rod-shaped (bacilli), + helical (spirochaete). 2. Prokaryotes – Archaea : a. Unicellular; have cell walls; some are autotrophic; some are chemotrophic. b. Archaea are “extremophiles”- they are suited to life in extreme conditions. c. Biotechnology has benefited greatly from archaea that survive in extremely high temperature e.g. an enzyme made of such organisms can be heated to high temps and still perform its functions. 3. Eukaryotes – Animalia: a. “Eukaryote” = cells with nuclei. b. Multicellular; heterotrophic; complex organ systems.
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4. Eukaryotes – Plantae: a. Multicellular; autotrophic; complex organ systems; cellulose cell walls. 5. Eukaryotes – Fungi: a. Mostly multicellular; chitin cell walls; heterotrophs through absorption; tissues (not organs); can be pathogenic. b. Example: arthrobotyrs – soil fungus; create loops to trap and digest worms. 6. Eukaryotes – Protista: a. Mostly unicellular; some autotrophs (e.g. algae), some heterotrophs (protozoa); can be pathogenic. b. Examples: kelp, phytoplankton, paramecium, slime mold, trypanosome, etc. Other:
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This note was uploaded on 12/18/2011 for the course BIOL 115 taught by Professor Brown during the Fall '08 term at McGill.

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Bio notes section 1 - Biology Notes Section 1: Lectures...

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