bio 1m03 exam notes

EVANS

bioscience book - 1, 24, 25, 26, 27, 50, 51, 52, 53, 54,55

hhe - 10-17

CHAPTER ONE – BIOLOGY AND THE TREE OF LIFE
CHAPTER ONE
 The cell theory and theory of evolution by natural election are unified by ancestry and descent.
 Evolutionary relationships can be represented by phylogenetic trees
Cell Theory
 Cell – highly organized compartment bounded by plasma membrane containing concentrated chemicals in an aqueous solution
 Cell Theory – all organisms are made of cells and all cells come from pre-existing cells o All cells are descended from a progenitor cell – the zygote
 Hypothesis – proposed explanation
 Prediction – something measurable and must be correct if the hypothesis is correct
 Louis Pasteur – designed an experiment to test if cells arose spontaneously or if they were the result of pre-existing cells
 Since all cells come from pre-existing cells, all organism are related by common ancestry, even multi-cellular organisms
Theory of Evolution
 Darwin (studied in the Galapagos) and Wallace (studied in South East Asia) proposed that all species are related by common ancestry; they also proposed that the characteristics of a species can be modified from generation to generation
 Evolution – postulates that: o Species are related to one another o Species can change through time
 Natural Selection – process that explains how evolution occurs -> over time, it is the transition of genetic material
 Fitness – the ability of an individual to produce offspring
 Adaptation o A trait that increases the fitness of an individual o The process of a species acquiring fitness improving traits over time
 For natural selection to occur these are required: o Variation in traits o Heritable traits (not environmental) o Traits that influence fitness
 If certain characteristics lead to increased success in producing offspring then these traits become more common in the population over time
 Natural selection acts on