Chapter 1 Lecture Outline

Chapter 1 Lecture Outline - Biology 100 Vandan Desai...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology 100 Vandan Desai 1 Chapter 1: Biology and the Tree of Life (Lecture Outline) --------------------------------------------------------------------------------------------------------------------- Theory: an explanation for a very general class of phenomena or observations; subjected to repeated tests, supported by consistent evidence, and may be modified and/or discarded h Cell Theory – all organisms made of cells and all cells come from preexisting cells h – species have changed through time and all species are related to one another through common ancestry o Established that bacteria, mushrooms, roses, and robins – part of a family tree (similar to the genealogies that connect individual people) I. The Cell Theory A. Pattern Component of the Cell Theory (A pattern observed in nature) 1. Cells are first described and identified in cork tissue (Hooke, 1665) and in water and a variety of living tissues (van Leeuwenhoek) 2. Plant tissues are determined to be composed of cells (Malphigi, 1670s) 3. Schleiden & Schwann (1839) used inductive reasoning to claim that all organisms consist of cells 4. Thousands of supporting observations led to this broad generalization Cell: a highly organized compartment that is bounded by a thin, flexible structure called a plasma membrane and that contains concentrated chemicals in a aqueous solution B. Process Component of the Cell Theory (A mechanism or process that creates pattern) 1. Virchow hypothesis – Cells are produced only when preexisting cells grow and divide (1858) 2. Alternative hypothesis – Cells arise spontaneously from nonliving materials 3. Pasteur experiment is designed to test the two hypotheses a) Nutrient broth is placed in a straight-neck flask and a swan-neck flask; each is boiled. Condensed water fills the curve of the swan-neck flask b) Bacteria cells soon grow in the straight-neck flask, which is open to air, but not in the swan-neck flask, where condensed water prevents access of air to the nutrient broth. Air contains dust particles with
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/08/2010 for the course BIOL 100 taught by Professor Staff during the Fall '07 term at UMBC.

Page1 / 4

Chapter 1 Lecture Outline - Biology 100 Vandan Desai...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online