AP Biology Mrs. Becker

Chapter 1 Introduction: Themes in the Study of Life

What are Themes? u General principles or ideas that occur over and over. u “Themes” are not a test item, but they are a framework to organize the study of Biology.

AP Biology Themes 1. 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? u We will see the “themes” at various times throughout the course. u Themes can be the basis of essay exams u Ex. Regulation of …

Question u How do we know what is alive and what is not? u What are the properties of Life?

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

1. Order u Living things are highly organized in structure and function.

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

u Structure and Function are related at all levels

2. Reproduction u Organisms reproduce their own kind.

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

3. Growth & Development u Organisms increase in size and complexity.

u Growth - increase in size. Development - increase in complexity. u Life - grows by internal changes.

4. Energy Processing u Organisms take in energy and transform it to do work.

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

5. Response To Environment u Organisms respond to changes or stimuli in their environment.

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

6. Regulation u Life processes must be controlled and adjusted. u Organisms maintain their internal environment within tolerable limits by homeostasis. u “homeo” = same u “stasis” = state

7. Evolutionary Adaptation u Organisms change over time because of their adaptations to their environment.

u 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 Response to the environment Reproduction Growth and development Energy processing 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 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig. 1-4 The biosphere Communities Populations Organisms Ecosystems Organs and organ systems Cells Cell Organelles Atoms Molecules Tissues 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 SpeciesGenusFamilyOrderClassPhylumKingdomDomain 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 (a) DOMAIN BACTERIA (b) DOMAIN ARCHAEA (c) DOMAIN EUKARYA Protists Kingdom Fungi Kingdom Plantae 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: u A process. u A way of “knowing” u Based on observations and experiments

Observations: u Are the “keystone” to Science. u If it can’t be “observed”, it can’t be studied by the Scientific Method. u Can be made through your senses or through the use of tools.

Two types of Science 1. Discovery or Descriptive Science u Naturalists, human genome u Based on observations, but may lead to experiments u Inductive Reasoning – logic flows from a set of specific observations to a general conclusion

2. Hypothesis based Science u Science by experimentation u Hypothesis testing in the form of “If…then…” u Deductive Reasoning - logic flows from general to specific

Example u When I throw a ball in the air, why does it come back down? u Inductive u Whenever I have thrown a ball in the past, it always comes back down u Specific observations to general conclusion

u Deductive u Gravity attracts two objects u If I throw the ball into the air, then gravity should draw the ball to the earth

Scientific Method: u Outlines a series of steps for answering questions. u Obtains “evidence” through the use of experiments.

Scientific Method Steps 1. 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 u Nothing is ever proven in science u Can only be disproven u Experiments either support or fail to support a particular hypothesis u Disproving a hypothesis is as important as supporting it

Theory u Broader in scope than hypothesis. u Not determined by single experiment, but have been supported by many experiments by many scientists.

Theory u Comprehensive explanation supported by abundance of evidence u Theories allow predictions

Examples of Theories u Atomic Theory u Gravitational Theory u Theory of Relativity u Cell Theory u Theory of Evolution by Natural Selection

Basic Evolution u Nothing in Biology makes sense except in the light of Evolution. u Theodosius Dobzhansky American Biology Teacher 35: , 1973.

Success is measured by: 1. Survive 2. 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 u Themes can provide a common framework for learning Biology u What are the characteristics of Life? u What is Science and how does it work? u Evolution’s role in the study of Biology