Chapter 1 - Chemical, Cellular, and Evolution

Principles of Biology

Observation

Act of viewing the world around us

Hypotheses

A tentative explanation for one or more observations

Experimentation

A disciplined and controlled way of learning about the world and testing hypotheses in an unbiased manner

Variable

The feature of an experiment that is changed from one group to the next

Test Group

The group exposed to the variable

Control Group

The group not exposed to the variable

Scientific Inquiry

A deliberate, systematic, careful, and unbiased way of learning about the natural world

Theory

General explanation of a natural phenomenon supported by a large body of experiments and observations

1st Law of Thermodynamics

Energy can neither be created nor destroyed - only transformed from one form to another

2nd Law of Thermodynamics

The degree of disorder in the universe tends to increase as energy transforms

Degree of Disorder

The number of possible positions and motions of molecules

Entropy

The degree of disorder in a system

Cell

The simplest self-reproducing entity that can exist as an independent unit of life

Cell Membrane

Surrounds the cells cytoplasm, separates the inside from the outside

Nucleus

The compartment of the cell that houses the DNA in chromosomes

Prokaryotes

Organisms whose cell does not contain a nucleus

Prokaryotes Example

Archaea and Bacteria

Eukaryotes

Organisms who cells do contain a nucleus

Eukaryotes Example

Plants and Animals

Fungi and Protists

Bacteria

Single celled prokaryotes

How do bacteria reproduce?

Binary fission

Archaea

Single celled prokaryotes

How do archaea reproduce?

Binary fission

Eukarya

Multicellular eukaryotes

How do eukarya reproduce?

Divide by mitosis

What is the 2nd essential feature to cells?

Ability to store and transmit information

Deoxyribonucleic acid (DNA)

The principal molecule of biological heredity. A polymer of nucleotides

Ribonucleic Acid (RNA)

A molecule chemically related to DNA and is synthesized as a complement to its DNA template

What does RNA do?

It is involved in protein synthesis

Proteins

Key structural and functional molecules that do the work of the cell

Transcription

The synthesis of RNA from DNA

Translation

Synthesis of a polypeptide chain corresponding to the sequence present in a molecule of RNA

Central Dogma

The observation that information in a cell usually flows from DNA to RNA to protein

What is the 3rd key feature of cells?

The ability to harness energy from the environment

Metabolism

Chemical reaction within cells which convert one molecule into another, produces ATP

Adenosine Triphosphate (ATP)

Energy which cells use

What causes environmental variation

Variation caused by differences in the environment such as sunlight exposure