Presentation on theme: "Biology The Study of Life. What is Biology in the 21 st Century? How is studying Biology different today than in the past? How does studying Biology affect."— Presentation transcript:
Biology The Study of Life
What is Biology in the 21 st Century? How is studying Biology different today than in the past? How does studying Biology affect your life? Why should you take this class? How has advancement in science benefited humanity?
Course Topics Unit 1 – Introduction – Biology 21 st century – Chemistry of Life Unit 2 - Cells – Structure and Function – Energetics – Growth and Division Unit 3 – Genetics – Meiosis – Mendelian Genetics – DNA to Proteins – Biotechnology Unit 4 – Evolution – Evolution by Natural Selection – Populations – History of Life Unit 5 – Classification – Systematic Taxonomy – Phylogeny and the Tree of Life – Biodiversity Unit 6 - Ecology – Principles of Ecology – Interdependence – Biosphere – Human Impact
Earth supports an amazing diversity of life biosphere = everywhere life exists
Earth supports an amazing diversity of life Every part of the biosphere is connected with every other part. The biosphere includes many environments. Biodiversity increases at the equator and decreases toward the poles
Earth supports an amazing diversity of life 1.All levels of life have systems of related parts 2.Structure and function are interdependent in Biology 3.All life maintains homeostasis to survive in diverse environments 4.Evolution explains the unity and diversity of life Nothing in Biology makes sense except in the light of evolution.
Earth supports an amazing diversity of life A biological species is defined as a group of individuals that will breed to reproduce. – Scientists have described over 1.7 million of the world's species of animals, plants and algae, as of Mammals make up one of the smallest groups, with just 5,490 members. Altogether the earth's oceans, lakes, continents and islands support over 62,000 identified species of vertebrate animals and 320,000 species of plants.
A small sample of biological diversity
Earth supports an amazing diversity of life So...how many are there? According to a new report co- authored by Derek Tittensor at UNEP's World Conservation Monitoring Centre (UNEP- WCMC), in Cambridge, UK, the estimate is around 8.7 million. – 86% of all species on land and 91% of those in the seas have yet to be discovered, described or catalogued.
All organisms share certain characteristics. Biology is the scientific study of all forms of life
Life’s basic characteristic is a high degree of order
An organism is any individual living thing. –All are made of one or more cells.
– All need energy for metabolism. What does all life have in common? –All are made of one or more cells. –All respond to their environment. –All have DNA that they pass on to offspring.
Cell Theory Schleiden Schwann Virchow a)All living things consist of cells. b)Cells are an organism’s basic unit of structure and function. c)All cells come from other cells.
Metabolism Energy Utilization
Energy Flow Activities of life require work Work depends on sources of energy Energy exchange between an organism and environment often involves energy transformations In transformations, some energy is lost as heat Energy flows through an ecosystem, usually entering as light and exiting as heat Sunlight Ecosystem Heat Chemical energy Consumers (including animals ) Producers (plants and other photosynthetic organisms)
Respond to their environment
Interaction With Environment and Energy Flow Organisms are open systems The dynamics of an ecosystem include two major processes Cycling of nutrients, in which materials acquired by plants eventually return to the soil The flow of energy from sunlight to producers to consumers
The genetic material: DNA DNA (deoxyribonucleic acid) The substance of genes- instructions to make protein and protein makes the organism what it is. Units of inheritance passed from parents to offspring. Double stranded molecule made of 4 nucleotides (ATGC). Human genome is 6 billion nucleotides long in 23 pairs of chromosomes.
Growth and Development
Unifying Themes in Biology 1.All levels of life have systems of related parts 2.Structure and function are interdependent in Biology 3.All life maintains homeostasis to survive in diverse environments 4.Evolution explains the unity and diversity of life Nothing in Biology makes sense except in the light of evolution.
Biological organization is based on a hierarchy of structural levels Ecosystems The biosphere Organisms Populations Communities Cells Organelles Molecules Tissues Organs and organ systems Cell 1 µm Atoms 10 µm 50 µm
SYSTEMS and Emerging Properties Each level, ATOM to the BIOSPHERE, is organized. Unique properties are revealed at each level- they “emerge” Properties result from interactions between the components. “The total is greater than the sum of it’s parts”… a hammer functions because of it’s head and handle- together. Example: Social interactions are affected by the interaction of chemicals in the brain.
Form fits function
Evolution Evolution is the core theme of biology. Evolution accounts for life’s unity and diversity Implies that all living things are related. The common ancestors are prokaryotes that existed 3.5 billion years ago.
Evolution – unity: all species descended from a common ancestor – diversity: modifications that evolved as species branched from their common ancestors
Unity in the Diversity of Life Underlying life’s diversity is a striking unity, especially at lower levels of organization In eukaryotes, unity is evident in details of cell structure Cilia of windpipe cells Cilia of Paramecium 15 µm5 µm
Can you explain the architecture of eukaryotic cilia?
Observations: a.)Individual variation. b.)Struggle for existence. Inference: a.)Differential reproductive success. b.)Evolutionary adaptation The evolutionary view of life came into sharp focus in 1859, when Charles Darwin published On the Origin of Species by Natural Selection “Darwinism” became almost synonymous with the concept of evolution Darwin The Concept of Natural Selection. Charles Darwin (1809–1882)
The Origin of Species articulated two main points The Origin of Species articulated two main points Descent with modification (the view that contemporary species arose from a succession of ancestors) Descent with modification (the view that contemporary species arose from a succession of ancestors) Natural selection (a proposed mechanism for descent with modification) Natural selection (a proposed mechanism for descent with modification) Darwin The Concept of Natural Selection
Adaptation Natural selection is often evident in adaptations of organisms to their way of life and environment Bat wings are an example of adaptation
Is evolutionary adaptation a product of natural selection? Thomas Malthus: organisms will produce more offspring than can be supported with available resources. Survival of the fittest- fitness is measured by reproductive success. Many related organisms have similar features adapted for specific ways of life. Such kinships connect life’s unity and diversity to descent with modification. Natural selection eventually produces new species from ancestral species. Natural selection eventually produces new species from ancestral species. Thomas Malthus ( )
Diversification of finches on the Galápagos Islands
Scientific Inquiry Science “to know” Has limits – only what can be observed and measured. Can’t prove – only disprove Must be able to test (hypotheses) Experimental results must be repeatable Utilizes modeling to represent ideas
Scientific Inquiry Inquiry is a search for information and explanation, often focusing on specific questions The process of science blends two main processes of scientific inquiry: –Hypothesis-based science attempts to seek natural causes and explanations of observations –Proposes a possible explanation and tests its validity –Discovery science describes nature through careful observation and data analysis –Example of discovery science: understanding cell structure
Idealized version of Scientific Process
Where does it begin? – Observation is the active acquisition of information from a primary source. In living beings, observation employs the senses. – Your assignment Observe the object at your table Use your senses to describe the object. In your notebook, write a minimum of one page describing the object in front of you. You may not use the following terms in your writing – Plant, flower, leaf, petal, stem, stalk
Theory Comprehensive explanation supported by abundant evidence. Newton, Einstein, Darwin Gravity, Relativity, Natural Selection Idea that ties together observations and experimental results that previously seemed unrelated.
Science, Technology & Society The goal of science is to understand natural phenomena Technology applies scientific knowledge for some specific purpose Research feeds technology and vice versa.
Data Data are recorded observations Two types – Quantitative data: numerical measurements – Qualitative data: recorded descriptions Inductive reasoning involves generalizing based on many specific observation
Science is a social process
David Reznick conducting field experiments on guppy evolution in Trinidad Paul Serrano is digging into the past Behavioralist Jane Goodall recording observations on chimpanzees
Science, Technology & Society Energy Structure to function Interdependence
Dilemma: How to study Biology? – something complex such as an organism or cell cannot be analyzed without taking it apart. – If you take something apart it disrupts the system and interferes with the meaningful understanding of how it works.
Dilemma: How to study Biology? Systems Biology – seeks to understand the behavior of a whole system rather than its parts – Seeks to create models of the dynamic behavior of whole biological systems – An example is a systems map of how proteins interact in a fruit fly cell. The model may predict how a change in one part of a system will affect the rest of the system.
Systems biology uses three key research developments: – High-throughput technology: methods to generate large data sets rapidly – Bioinformatics: using computers and software to process and integrate large data sets – Interdisciplinary research teams