BIOL 100 Topic 1

Biology 100

Study of life and living organisms including their structure, function, growth, origin, evolution, and distribution

Characteristics of Life

Organization, metabolism, homeostasis, growth, reproduction, response to stimuli, adaptation through evolution

Cells

Basic unit of structure and function in living things; all organisms are made of one or more cells

Unicellular Organism

A single-celled organism that performs all life processes within one cell

Multicellular Organism

An organism composed of many cells that are specialized to perform different functions

Metabolism

All chemical reactions within an organism that allow it to maintain life

Homeostasis

Maintenance of a stable internal environment despite changes in external conditions

Growth

Process where an organism increases in size and/or number of cells

Reproduction

Process by which organisms produce new individuals of the same species

Response to Stimuli

Ability of an organism to detect and react to changes in its environment

Evolution

Gradual change in a species over time through adaptation and natural selection

Levels of Biological Organization

Atoms → Molecules → Cells → Tissues → Organs → Organ systems → Organism

Atoms

Smallest unit of matter that retains the properties of an element

Molecules

Groups of atoms bonded together representing the smallest unit of a chemical compound

Cell Theory

All living things are made of cells; cells are the basic units of life; all cells come from preexisting cells

Scientific Method

Step-by-step approach used by scientists to answer questions and solve problems

Steps of the Scientific Method

Observation → Question → Hypothesis → Experiment → Results → Conclusion

Hypothesis

A testable and falsifiable explanation for a scientific question or observation

Experiment

Procedure to test a hypothesis by collecting data under controlled conditions

Control Group

Group in an experiment that does not receive the experimental treatment; used for comparison

Independent Variable

The factor that is changed or manipulated in an experiment

Dependent Variable

The factor that is measured or observed in an experiment

Theory

A well-supported explanation of natural phenomena that has been repeatedly tested and confirmed

Law

A statement based on repeated experimental observations that describes an aspect of the world