AP Biology Mrs. Becker. Chapter 1 Introduction: Themes in the Study of Life

AP Biology

Mrs. Becker

Chapter 1Introduction: Themes in the

Study of Life

What are Themes?

General principles or ideas that occur over and over.

“Themes” are not a test item, but they are a framework to organize the study of Biology.

AP Biology Themes1. Science as a process

2. Evolution

3. Energy Transfer

4. Continuity and Change

AP Biology Themes

5. Relationship of Structure & Function

6. Regulation

AP Biology Themes

7. Interdependence in Nature

8. Science, Technology and Society

Why Themes?

We will see the “themes” at various times throughout the course.

Themes can be the basis of essay exams Ex. Regulation of …

Question

How do we know what is alive and what is not?

What are the properties of Life?

General Properties of Life

1. Order 2. Reproduction 3. Growth and Development 4. Energy Utilization 5. Response to the Environment 6. Homeostasis 7. Evolutionary Adaptation 8. The cell is the basic unit of life 9. Organisms die

1. Order Living things are highly

organized in structure and function.

Analyzing a biological structure gives us clues about what it does and how it works

Structure and Function are related at all levels

2. Reproduction Organisms reproduce their own

kind.

Life on Earth uses the nucleic acid and code for Heritable Information.

3. Growth & Development Organisms increase in size

and complexity.

Growth - increase in size. Development - increase in complexity.

Life - grows by internal changes.

4. Energy Processing

Organisms take in energy and transform it to do work.

Organisms are “open” systems, they must continually take in energy.

5. Response To Environment

Organisms respond to changes or stimuli in their environment.

The speed of the response may be “fast” or “slow”.

6. Regulation Life processes must be controlled

and adjusted. Organisms maintain their internal

environment within tolerable limits by homeostasis.

“homeo” = same “stasis” = state

7. Evolutionary Adaptation Organisms change over time

because of their adaptations to their environment.

Organisms must have adaptations, move, or die!

Is this a “good” adaptation?

8. The Cell Is the “basic unit” of Life

9. Organisms Die or become non-life.

Order

Evolutionary adaptation

Responseto theenvironment

Reproduction

Growth anddevelopment

Energyprocessing

Regulation

Fig. 1-3

New properties emerge at each level in the biological hierarchy

• Life can be studied at different levels from molecules to the entire living planet

• The study of life can be divided into different levels of biological organization

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Fig. 1-4

The biosphere

Communities

Populations

Organisms

Ecosystems

Organs and organ systems

Cells

Cell

Organelles

Atoms

MoleculesTissues

10 µm

1 µm

50 µm

• Stepping stair on board

The Core Theme: Evolution accounts for the unity and diversity of life

• “Nothing in biology makes sense except in the light of evolution”—Theodosius Dobzhansky

• Evolution unifies biology at different scales of size throughout the history of life on Earth

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Organizing the Diversity of Life

• Approximately 1.8 million species have been identified and named to date, and thousands more are identified each year

• Estimates of the total number of species that actually exist range from 10 million to over 100 million

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Grouping Species: The Basic Idea

• Taxonomy is the branch of biology that names and classifies species into groups of increasing breadth

• Domains, followed by kingdoms, are the broadest units of classification

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig. 1-14Species Genus Family Order Class Phylum Kingdom Domain

Ursus americanus(American black bear)

Ursus

Ursidae

Carnivora

Mammalia

Chordata

Animalia

Eukarya

The Three Domains of Life

• The three-domain system is currently used, and replaces the old five-kingdom system

• Domain Bacteria and domain Archaea comprise the prokaryotes

• Domain Eukarya includes all eukaryotic organisms

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig. 1-15(a) DOMAIN BACTERIA

(b) DOMAIN ARCHAEA

(c) DOMAIN EUKARYA

Protists

Kingdom Fungi

KingdomPlantae

Kingdom Animalia

• The domain Eukarya includes one Kingdom that is unicellular/colonial and three multicellular kingdoms

• - Protista

– Plantae

– Fungi

– Animalia

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig. 1-15c

(c) DOMAIN EUKARYA

Protists

Kingdom Fungi

Kingdom Plantae

Kingdom Animalia

Science is:

A process. A way of “knowing” Based on observations and

experiments

Observations:

Are the “keystone” to Science. If it can’t be “observed”, it can’t

be studied by the Scientific Method.

Can be made through your senses or through the use of tools.

Two types of Science1. Discovery or Descriptive Science

Naturalists, human genome Based on observations, but may

lead to experiments Inductive Reasoning – logic flows

from a set of specific observations to a general conclusion

2. Hypothesis based Science Science by experimentation Hypothesis testing in the form

of “If…then…” Deductive Reasoning - logic

flows from general to specific

Example When I throw a ball in the air,

why does it come back down? Inductive

Whenever I have thrown a ball in the past, it always comes back down

Specific observations to general conclusion

Deductive Gravity attracts two objects If I throw the ball into the air,

then gravity should draw the ball to the earth

Scientific Method:

Outlines a series of steps for answering questions.

Obtains “evidence” through the use of experiments.

Scientific Method Steps1. Identify the problem.2. What is already known?3. Formulate a hypothesis.4. Conduct an experiment

changing one variable at a time. All other factors are held constant. (Why?)

Scientific Method Steps

5. Collect data. Have replicates (Why?)

6.Compare data to hypothesis. Does the data support the hypothesis?

7. Conclusions and new hypothesis.

Comment Nothing is ever proven in

science Can only be disproven

Experiments either support or fail to support a particular hypothesis

Disproving a hypothesis is as important as supporting it

Theory

Broader in scope than hypothesis.

Not determined by single experiment, but have been supported by many experiments by many scientists.

Theory

Comprehensive explanation supported by abundance of evidence

Theories allow predictions

Examples of Theories

Atomic Theory Gravitational Theory Theory of Relativity Cell Theory Theory of Evolution by

Natural Selection

Basic Evolution

Nothing in Biology makes sense except in the light of Evolution. Theodosius Dobzhansky

American Biology Teacher 35:125-129, 1973.

Success is measured by:

1. Survive2. Reproduce

Note – organisms survive because of their adaptations, they do not adapt to survive.

Evolution in Biology

1. What is the adaptive value of ________?

2. Why has ______ persisted over time?

3. How does _____ increase survival or reproduction?

Summary

Themes can provide a common framework for learning Biology

What are the characteristics of Life?

What is Science and how does it work?

Evolution’s role in the study of Biology