Biology Unit 1 - Nature of Science

What is Science?

  • An Organized way of Gathering and Analyzing Evidence about the natural world

  • Scientific facts Change

    • facts are open to testing, discussion, and revision

3 Goals of Science

  1. Provide a natural explanation for events in the natural world

  2. Use explanations to understand patterns in natures

  3. Make useful predictions about natural events

Science Methodology

  • General Style of scientific investigation used by most scientists

  • No official steps to the scientific method

  • Francesco Redi - disproved spontaneous generation using scientific methodology

    • Spontaneous Generation - life comes from nothing

Observations

  • The act of noticing an describing events in an orderly way

    • Inference - use prior knowledge to make a logical interpretation

  • All experiments start with observation

  • Ask questioned based off observations and inferences

Hypothesis

  • Proposed Answer to a question that Can Be Tested

  • ex. If _____requirement______ then ____result____,

Experiment

  • Procedure designed to Support or Refute a hypothesis

  • Parts:

    • Independent Variable - what the experimenter changes

    • Dependent Variable - changes in response to the independent

    • Experimental Group - manipulated/changed in order to test

    • Control Group - remains the same; used for comparison

Collect Data

  • Data - detailed research of experiment observations

    • Quantitative - numbers, measurement

    • Qualitative - characteristics

  • organized into tables, charts, and graphs

  • Graphing Data

    • Bar Graphs - shows comparison

      • Dependent Variable - Y-axis

      • Independent Variable - X-axis

    • Line Graphs - shows trends over time

      • same x and y axis

Draw Conclusions

  • Analyze data

  • Compare results to the hypothesis

    • support or refute

    • rarely correct or incorrect

    • hypothesis revision is typically needed

Communicate Results

  • Share results for comparison, evaluation, and further testing

  • Peer-Reviewed Article - experiment that has undergone expert scrutiny to assess the quality

Develop Theory

  • Theory - well-tested Scientific Explanation of natural event that Unifies a Broad Range of Observations and is supported by Data

  • No theory is absolute, science is always improving

Theory vs Law

  • Theory - Explains how things happen

  • Law - Predicts what will happen

What is Biology?

  • the study of the Living World (life)

  • Organism - any individual living thing

  • Living things - must have the 8 characteristics of life

8 Characteristics of Life

  • DR G CHEER

  • DNA

    • Deoxyribonucleic Acid

    • contains Genetic Information and Instructions for ALl of life

    • passed on from Parent to Offspring

  • Respond to Environment

    • Organisms can Detect and Respond to Stimuli in their environment

    • Stimulus - a Signal that Causes an organism to take action

      • Positive Feedback Loop - Maintains its direction and possibly accelerates it

        • Blood clotting, childbirth contractions

      • Negative Feedback Loop - Changes the direction of the stimulus

        • Blood sugar and temp regulation

  • Growth and Development

    • All organisms

      • Growth - Increase in amount of Material in an organism

      • Development - Series of changes an organism goes through

  • Cells

    • All organisms are made up of At Least 1 Cell

      • Unicellular - 1 cell

      • Multicellular - many cell

    • Prokaryotic

      • Unicellular

      • Lacks Nucleus

      • ex. bacteria

    • Eukaryotic

      • Multicellular

      • Has Nucleus

      • ex. plants, animals, and fungi

  • Homeostasis

    • Maintaining a Stable Internal Environment

    • All organisms

    • ex. body temp, pH, gas exchange

  • Evolve

    • Organisms Adapt and become more suitable to their environment

    • Over Many Generations, group of organisms Evolve, or change overtime

  • Energy

    • Metabolism - Chemical Reactions that take place Inside an organism that either Build or Break Down Molecules necessary for Life

      • Anabolism - Builds Up

      • Catabolism - Breaks Down

    • All organisms need to Obtain and Use energy and materials

  • Reproduction

    • Process where organisms make more of their own kind

    • Asexual Reproduction - one parent produces a genetically Identical offspring

    • Sexual Reproduction - 2 parents Combine genetic information to create a genetically Unique offspring