Biology: The Study of Life C1- pp 2-31

C1 Table of Contents Section 1.1 What is biology? Slides 3-15 Section 1.2 The World of Biology The World of BiologyThe World of Biology Slides Section 1.3 The Methods of Biology The Methods of BiologyThe Methods of Biology Slides 25-34

What is biology? Study of living things Everything from bacterial cell, mold, amoeba, mushrooms, plants & humans Unified by 6 major themes:

Theme 1 Cell Structure and Function Basic structure of life All organisms are made of cells & come from other cells Differentiation process in which cells become specialized during development

Theme 2 Stability & Homeostasis All living things must maintain internal conditions that maintain life.

Theme 3 Reproduction & Inheritance All organisms reproduce or produce new offspring

Theme 3 DNA- hereditary info in a large molecule called deoxyribonucleic acid Gene segment of DNA that contains coding for a protein, unit of hereditary information

Theme 3 Sexual Reproduction combines genetic material from two parents Asexual Reproduction requires only one individual & does not involve union of gametes (sex cells)

Theme 4 Evolution populations of organisms evolve or change over time driven by a process called natural selection

Theme 4 Evolution all the changes that have formed life on Earth from its earliest beginnings to today’s diversity

Theme 4 Natural Selection Process by which organisms with favorable variations reproduce at higher rates than those without such variations

Theme 5 Interdependence of Organisms All organisms interact with others Ecology study of relationship btwn organisms & their environment

Theme 5 Biotic & Abiotic components of an environment or living & nonliving

Theme 6 Matter, Energy & Organization Homeostasis is maintained by constant source of energy. Ultimate source is the sun. All life depends on autotrophs doing photosynthesis

Theme 6 Photosynthesis conversion of light into chemical energy (glucose) Autotrophs org uses energy to make organic molecules from inorganic substances Heterotrophs eat other organisms

1.2 The World of Biology 6 Characteristics of Life No matter how diverse organisms are, all share certain characteristics:

1.2 The World of Biology 6 Characteristics of Life All living things are: made of cells; Highly organized; Use energy; Maintain homeostasis; Grow & develop; Reproduce

Characteristic 1 Cells are basic unit of structure & function

Characteristic 2 Highly organized at molecular (DNA & proteins) and cellular levels (structures for specific functions)

Characteristic 3 All living things use energy to maintain organization, homeostasis, grow, develop, reproduce… Metabolism sum of all chemical processes in living things

Characteristic 4 Homeostasis Single cells must maintain conditions necessary to stay alive Multicellular organisms use organ systems to help maintain homeostasis

Characteristic 5 Growth & development Living things grow by cell division Development is process in which new cells enlarge & change until they reach maturity

Characteristic 6 Reproduce essential for the continuation of the species but not for the individual organism This is the only one not essential to the individual.

The World of Biology Not all organisms have been identified & studied. Some are so small that they escape detection while others are in places so remote they can’t be explored.

1.3 Methods of Biology ObservationHypothesisExperiment Collect data Analyze results Draw conclusions Report results

Observation Observe surroundings Ask questions about problems Research available info to make an educated hypothesis

Hypothesizing Possible explanation for problem based on research In form of statement Can be tested May be proven wrong but cannot be proven true beyond all doubt Statement must include variable being tested & expected outcome

Example Hypothesis The lower the pH of the water used to water the plants, the less growth will occur. If, then statement

Experimenting Most experiments are controlled by comparing control group with experimental grp Test one variable at a time Run many samples Collect either quantitative or qualitative data

2 parts to controlled experiment 1) Exp group has all conditions kept the same as control but includes the independent variable being tested 2) Control group all conditions kept the same but does not include independent variable (being tested) Dependent variable being measured or observed

Steps 4 & 5 Collect data Analyze results

Draw Conclusions Summary of lab in paragraph form Relate back to hypothesis Analyze data in graphs Ask yourself: “Was the hypothesis supported or not?” If not, reformulate hypothesis & test again

Report Results Verify your results, then publish Other scientists use your work as a springboard for other problems

Theory An explanation of a natural phenomenon that is supported by a large body of scientific evidence… continually being verified.