AP Biology Study of Life Chapter 1 Themes

AP Biology Why study themes of Biology?  Biology is an ever expanding body of knowledge  too much to memorize it all  need to generalize  create a framework upon which to organize new knowledge  themes are the key to understanding the nature of living organisms

AP Biology 8 Themes in biology  Science as a process of inquiry called inductive reasoning  questioning & investigation  Evolution  Energy transfer  Continuity & Change  Relationship of structure to function  Regulation  Interdependence in nature  Science, technology & society

AP Biology Science as a process of inquiry

AP Biology Science as a process of inquiry  Built on repeatable observations & testable, falsifiable hypotheses

AP Biology Natural selection  Evolutionary change is a product of the process of natural selection –can produce new species Organisms don’t adapt; Organisms have adaptations.

AP Biology "Nothing in biology makes sense except in the light of evolution." -- Theodosius Dobzhansky March 1973 Geneticist, Columbia University ( )

AP Biology Evolution explains unity & diversity (all life is connected through evolution)  Unity  what do organisms have in common & why do similarities exist?  common biochemistry & physiology  evolutionary relationships  connected through common ancestor  Diversity  but why are there differences?  natural selection  adaptations allow different individuals to survive in different environments

AP Biology The origin of species  Charles Darwin presented two ideas:  Current species arose from a succesion of ancestors through “decent with modification “ (evolution)  The mechanism of evolution is natural selection He observed this by 1. Individuals in a population of any species vary in many heritable traits 2. Any population can potentially produce far more offspring than the environment can support Result of these 2  a struggle for existence among variant members of a population

AP Biology

Organizing systems  Making sense out of the diversity  Hierarchical scheme  Loss of order or free energy flow = death Eastern gray squirrel Sciurus carolinensis

AP Biology 3 Domains of Life Bacteria, Archaea, Eukarya EukaryaBacteriaArchaea

AP Biology Energy transfer  Life is an open system  need input of energy  energy flows through  energy comes in, energy goes out  need a constant input  need input of materials  nutrients are recycled around & around ENTROPY RULES! DECOMPOSERS RULE, too! nutrients

AP Biology Energy utilization You think they’re eating… They’re harvesting energy!

AP Biology Continuity & change  Continuity of life is based on heritable information in the form of DNA  DNA – the genetic material – carries biological information from one generation to the next You can make more, a lot like you! TRAITTRAIT

AP Biology Form follows function  The alignment of structure & function is seen at all levels of biology organism cell organelle organ

AP Biology Regulation  Organisms need to maintain a “steady state” in the face of changing conditions  maintain homeostasis  achieve this through feedback  monitor the body like a thermostat  turn on when it’s needed, off when its not

AP Biology Interdependence  No organism is an island standing alone  communities, ecosystems

AP Biology Science, technology & society  Science & technology must function within the rules of society  ethics

AP Biology Themes  Science as a process of inquiry  questioning & investigation  Evolution  Energy transfer  Continuity & Change  Relationship of structure to function  Regulation  Interdependence in nature  Science, technology & society

AP Biology What Makes Something Living?  Living things share the same 7 characteristics:  A. Organization and cells  B. Response to stimuli  C. Homeostasis  D. Metabolism  E. Growth and development  F. Reproduction  G. Evolution

AP Biology ANY QUESTIONS?