human biology, science, and society chapter 1 gateway community college biology 156
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Human Biology, Science, and Society
Chapter 1Gateway Community CollegeBiology 156
The Characteristics of Life Living things:
Have a different molecular composition than nonliving things
Require energy and raw materials Are composed of cells Maintain homeostasis Respond to their external environment Grow and reproduce Populations evolve
Different molecular composition All things on the earth are comprised of
the same 100 elements Only a few of these elements are used by
living organisms Living organisms can combine elements in
unique ways to form molecules Proteins Carbohydrates Lipids Nucleic acids Etc.
Non-living things
Require energy and raw materials Metabolism
The physical and chemical processes involved in transforming energy and molecules so that life can be maintained
Are composed of cells Cell
The smallest unit that exhibits all the characteristics of life
Unicellular Only one cell
Multicellular Many cells and many
different kinds of cells
Maintain homeostasis Homeostasis
Maintenance of the relatively constant internal environment
Regulation Selective barriers Tissues Organs Organ systems
Respond to external environment Reaction to environmental conditions
Grow and reproduce Grow and ultimately reproduce
Populations evolve
How Humans Fit into the Natural World 5 Kingsoms based on:
Presence or absence of a nucleus Number of cells Type of metabolism
Prokaryotes (1 Kingdom) No nucleus present
Eukaryotes (4 Kingdoms) Cell nucleus present
Kingdoms Monera
Bacteria Animalia
Animals Plantae
Plants Fungi
Mushrooms, yeast, etc. Protista
Protozoa
Prokaryote Domains Domain system
Further classification of prokaryotic organisms
The 3-domain system Bacteria Archae Eukarya
Comprises all 4 kingdoms
Humans Kingdom Animalia
Vertebrates Nerve cord and a
backbone Mammals
Vertebrates with mammary glands who nurse their young
Primates Human, apes, monkeys
Genus Second smallest unit of classification Humans are Homo sapiens Characteristics make us unique Interbreed
Species Smallest classification system One or more populations of organisms with
similar physical and functional characteristics Interbreed Produce fertile offspring under natural conditions
American Indian Asian African Caucasian Latino Mediterranean Indian Etc.
Defining Characteristics of Humans Bipedalism Opposable Thumbs Large Brain Capacity for complex language
Bipedalism Humans:
Stand upright Walk on two legs Frees our hands for work
Latin: bis = twice, pes = foot
Opposable Thumbs Fingers can be moved into
positions that oppose the thumb Finger tips can pinch together Other primates use the side of
the finger to grasp with the thumb
Large Brain Large brain mass relative to body size
Capacity for Complex Language Development of complex vocal language,
sounds, gestures, signs and symbols Communicates concepts and emotions Adaptation of language into written forms
Studying Levels of Organization Biology can be studied at any level
Numerous areas of study in the biological sciences
Atom and molecule Cell Tissue Organ Organ System
Organism Population Community Ecosystem Biosphere
The Scientific Method Test ideas
1. Observe and Generalize2. Formulate a hypothesis3. Make a testable prediction4. Experiment or Observe5. Modify Hypothesis if
necessary and repeat
Observe and Generalize Inductive reasoning
Specific to general
We observe something, and based upon past experience or knowledge, generalize what we see
It is starting to get cold outside winter is coming
Formulate a hypothesis
Tentative statement about the natural world
Leads to a testable deduction
An “educated guess” to explain what we observed
Make a Testable Prediction Speculation
Things that cannot be tested Hot air Half-truth Assumption
Testable predictions Very specific predictions Working hypothesis
Deductive reasoning Apply a general case to a specific one
If . . . then
Experiment or Observe Truth or falsehood is based
on an experiment or set of tests
Experiment Carefully planned and executed
manipulation of the natural world that has been designed to test your prediction
Performed using very-strict controlled conditions
Controlled experiments Variables
Modify Hypothesis and repeat If your prediction is false . . .
Modify your hypothesis to fit your experimental findings
If your prediction is true . . . Test further variables
Making the Findings Known Publication of findings
Presentations Articles Books Etc.
Pier-review Most accurate form of publication
Conditions of the experiment data are very specific
Theory Broad hypothesis Extensively tested Supported over time Explains a broad range of scientific facts High degree of reliability
Sources of Scientific Information Technical information is usually for the
scientific community Science magazines and nonfiction books
Designed for the well-educated public General interest magazines and daily
newspapers Get information out quickly
Internet .org, .com, .edu, etc.
Misinformation
Critical Thinking Become a skeptic Statistics Graphs Anecdotes and scientific evidence Separate facts from conclusions Understand the difference between
correlation and causation
Skepticism A questioning attitude
Statistics Organizing and interpreting information
and data Confidence Standard error
Graphs A picture speaks a thousand words
Anecdotal Evidence A testimonial or short unverified report A generalized statement that may be true
Facts and ConclusionsFact
Verifiable piece of informationConclusion
Judgment based upon facts
The news media often misuses, or confuses facts and conclusions
Correlation and Causation Correlation
Pattern or relationship between two variables Causation
What causes something to happen Correlation does not specify causation
Role of Science Science improves Technology and the
Human Condition Science has limits Make informed decisions