Levels of Science

Atom

molecule

micromolecule

cell

tissue

organ

organ system

organism

population

community

ecosystem

biosphere

Definitions

Science: an organized way to learn about the natural world

Quantitative: numerical measurements (pounds, centimeters, volume)

Qualitative: description (color, size, texture)

The Scientific Method

1. Observe and State the Problem.

2. Form a hypothesis, an educated guess based on observations.

3. Test the hypothesis with an experiment that contains a control group and one or more experimental groups.

4. Record data in tables and make graphs.

5. Analyze the data by restating it in words and explaining what it means.

6. Form a conclusion based on the hypothesis you formulated earlier. This should restate the hypothesis and state whether it is supported or not supported. Replicate your work or revise your hypothesis and retest. Form a theory.

A theory develops when a particular hypothesis is supported repeatedly with data. Theories could be changed or modified when new data arises.

8 Characteristics of Life

Cells: the smallest unit of life

• Unicellular: one-celled organism

• Multicellular: many-celled organisms

Reproduction: essential otherwise it will become extinct

• Asexual: one cell, one parent, no genetic diversity

• Sexual: two different cells for offspring

Growth: changes in size or shape

Energy: all living things use energy

• Metabolism: overall energy state; ability to break down energy molecules to obtain energy.

Organization: enables organisms to maintain homeostasis and constantly engage in life presence.

Homeostasis: maintaining the stability of internal conditions

• Chemical Reaction: temperature, water content, food intake balanced

Response to stimuli: organisms react to anything that is out of their internal or external environment

Evolution: populations change over time through adaptations in the population