Chapter 1Ten Themes In The Study Of Life

Hierarchy of Organization

Atoms

Molecules

Organelles

Cells

Tissues

Organs

Systems

Organism

Population

Community

Ecosystem

Biome

Biosphere

Ecosphere

Emergent Properties

• Order – tendency to self organize

• Reproduction – biogenesis

• Growth and development

• Energy utilization

• Response to the environment

• Homeostasis – self regulation

• Evolutionary adaptation

With each step upward in the hierarchy of biological order, novel

properties emerge that were not present at the simpler levels of

organization.

“The whole is greater than the sum of its parts.”

How do we seek understanding?

• Reductionism – reducing complex systems to simpler components

• Holism – Study the entire system to truly understand it

The Cell Theory

• 1. All living things are composed of cells

• 2. All cells come from other cells

• 3. Cells are the units of structure and function

Two Major Kinds of Cells

Prokaryotic – first cell

Eukaryotic – true cell

E.M. of Prokaryotic Cells

DNA Basics

DNA is the substance of genes

Double helix

4 Bases (Adenine, Guanine, Cytosine, Thymine

Self-replicating molecule

Changes over time

All forms of life employ essentially the same genetic code

Organisms Are Open Systems That Interact Continuously With

Their Environments.

Living things both alter and are changed by their environment

Materials are recycled

Energy is lost as heat and not recycled

Energy Flow In The Ecosystem

Living Systems Are Regulated

Many Biological Processes Are Self -Regulating Through “Feedback”

Mechanisms

Negative Feedback

Positive Feedback

Evolution, Unity, And Diversity

The Evolutionary Connections Among All Organisms Explain the

Unity and Diversity of Life.

The Three Domains of Life

“Descent With Modification”

Connections

• Observation #1– Individual variation

• Observation #2 – Struggle for existence

• Inference – Differential reproductive success or “Natural Selection”

Natural Selection Is An Editing Process

The Process Of Science

“Science Is A Way Of Knowing”

Idealized Scientific Method

Inductive Reasoning

Hypothetico-deductive Reasoning

“If…then” Logic

“Fishing” For Answers

Theories Have Broad Explanatory Power

Theories Are Comprehensive