The Science of Biology Chapter 1

I. Introductory Terms Science: An organized way of using evidence, based on observations, to learn about the natural world. Observations: Information gathered using the senses. 1.Quantitative- involves numbers or measurements 2. Qualitative-involves characteristics or descriptions not easily measured or counted.

C. Biology: The study of life (living things) D. Organism: a complete individual living thing 1.Examples: spider, tree, etc.

II. Characteristics of living things Living things are Made up of units called cells Cell = basic unit of structure and function in all living things Multicellular = many cells Unicellular = 1 cell (like bacteria)

Living things Reproduce Asexual – 1 parent, no joining of sex cells or DNA Sexual – usually 2 parents, sex cells joined and DNA combined

Living things Grow & develop Cell division Cell enlargement Cell specialization Living things Respond to stimuli

E.Living things Use energy Autotroph: make own food (plants) Heterotroph: eat something Metabolism: chemical reactions that build up or break down materials

Living things Maintain homeostasis Regulation of an organism’s internal environment Optimizes conditions for metabolism

Living things display organization Cell structures, cells, tissues, and organs work together to support the organism

Levels of Organization Cellular Organization cells organelles molecules atoms The cell is the basic unit of life.

Levels of Organization Organismal Level organism organ systems organs tissues

Levels of Organization Population Level ecosystem community species population

Living things evolve over time Adaptation: an inherited characteristic that results from changes to a species over time, usually something that helps them survive

Mule: Living or not??

III. The Scientific Method - logical and organized methods of scientific study. SCHyTCo!!

State the problem The problem must specify how the results can be measured Format: What effect does the Independent (manipulated) Variable have on Dependant (responding) Variable? IV: The variable being tested DV: results of experiment, what you will be measuring.

Good or bad example? How does drinking pop affect concentration? Better --> How does drinking mountain dew affect concentration in class? Best --> How does drinking 1 can of mountain dew affect performance on a memory test?

Collect Background Info – research your problem. What things would you research for the mountain dew example? Ex. Amount of caffeine, how caffeine works, how memory works, etc.

Hypothesis = possible solution to problem; an educated guess based on background information Ex: scores on memory tests will be lower after drinking mountain dew

Test the hypothesis (experiment) Controlled experiment – all conditions the same except one variable Experimental group – group exposed to the variable Control group – not exposed to the variable, used as a comparison Number of trials: how many times the experiment is repeated

Conclusions Data – scientific facts collected during experiment Tables, graphs, charts Statistics – math that evaluates data Ex. Average growth rate of frogs during development

Definitions Theory an explanation of how a specific natural phenomenon occurs tested with repeated experiments and observations and found always to work

Law: a rule that describes, but doesn’t explain, a pattern in nature and predicts what will happen under specific conditions

Charles Darwin Served as naturalist on mapping expedition around coastal South America. Used many observations to develop his ideas Proposed that evolution occurs by natural selection

Darwin’s Evidence Similarity of related species - Darwin noticed variations in related species living in different locations

Darwin’s Evidence - Darwin realized that not all members of a population survive and reproduce. natural selection: individuals with superior physical or behavioral characteristics are more likely to survive and reproduce evolution: modification of a species over generations

Post-Darwin Evolution Evidence Fossil record Mechanisms of heredity Comparative anatomy Molecular evidence