Chapter 1- Invitation to Biology

• Scientific study of life• Lays the foundation for asking basic questions about life and the natural world

Why Study Biology?• To learn how organisms are constructed,

how they function, where they live, and what they do

• To help develop, modify, and refine ideas about life

Levels of Organization

Fig. 1.2, p.4

Levels of Organization

Fig. 1.2, p.4

Levels of Organization

Fig. 1.2, p.4

Levels of Organization

Fig. 1.2, p.4

Levels of Organization

Unicellular- single celled organism

Multicellular- many celled organism

Fig. 1.2, p.5

Levels of Organization

Population- group of one species in area

Fig. 1.2, p.5

Levels of Organization Community- many species in one area Ecosystem- community interacting with

physical environment

Fig. 1.2, p.5

Levels of Organization

Biosphere- surface and atmosphere of earth

Fig. 1.2, p.5

ALL LIVING THINGS… Require Energy

Energy = Capacity to do work Metabolism = Reactions by which cells acquire

and use energy to grow, survive, and reproduce

ALL LIVING THINGS… Are Made of Cells

Are composed of the same substances

from atoms to molecules to cells etc.

ALL LIVING THINGS… Sense and Respond

Organisms sense changes in their

environment and make responses to them

Receptors detect specific forms of energy

(stimuli)

Allows maintenance of homeostasis

ALL LIVING THINGS… Grow and Develop

Cell division increases the size of an organism.

The instructions from DNA allow cells to differentiate as the organism develops from egg to adulthood.

ALL LIVING THINGS… Reproduce

Have the capacity to reproduce based on instructions in DNA. This ability is not required for the survival of the individual, but must occur to continue the species. Two types

Asexual Reproduction- offspring produced without use of sex cells

Sexual Reproduction- offspring produced by joining sex cells

ALL LIVING THINGS… Adapt/Evolve

Adaptations are traits that give an advantage in a certain environment.

Variation of individuals comes from mutations and sexual reproduction.

Evolution is when these changes areas passed down from generation to generation.

CLASSIFICATION & Binomial Nomenclature

Devised by Carolus Linnaeus

First name is genus (plural, genera) which

helps to characterize the organism.

Homo sapiens - genus is Homo

Second name is species within genus.

Species characteristics are unique to that

species.

Homo sapiens – species is sapiens

Classification System

For Humans… Domain- Eukarya Kingdom- Animalia Phylum- Chordata Class- Mammalia Order- Primata Family- Hominidae Genus- Homo Species- Homo sapiens

For Jaguars… Domain- Eukarya Kingdom- Animalia Phylum- Chordata Class- Mammalia Order- Carnivora Family- Felidae Genus- Panthera Species- onca

3 Domains

Fig. 1-7, p.8

Bacteria Archaea Eukarya

Examples of Life’s Diversity

Fig. 1-8, p.8

Bacteria

Strep Throat- streptococcus

Tuberculosis bacteria

Archaea

Fig. 1-8c(2), p.9

Examples of Life’s DiversityProtists Fungi

Fig. 1-8c(10), p.9

Examples of Life’s Diversity

Animals Plants

From 5 to 6 Kingdoms

Single cells

No nucleus or

membrane-bound

organelles

Smaller, less complex

Ex: bacteria

Prokaryotic Organisms

Eukaryotic Organisms

Single- or multi-celled

Nucleus and other

membrane-bound

organelles

Larger, more complex

Ex: Animals, plants,

fungus

Mutation: Source of Variation

Mutation = change in structure of DNA Basis for the variation in heritable traits Most are harmful

Adaptive Trait / Adaptation A trait that gives the individual an advantage in survival or reproduction,

under a given set of circumstances

Evolution

Genetically based change in a line of descent over time

Population changes, not individuals

Natural Selection

Individuals vary in some heritable traits Some forms of heritable traits are more

adaptive Natural selection is differences in survival

and reproduction among individuals that vary in their traits

Adaptive forms of traits become more common than other forms

Figure 1.14

Scientific Method

Observe phenomenon

Develop hypotheses

Make predictions

Devise test of predictions

Carry out test and analyze results

Inductive Logic

Using observations and facts to arrive at

generalizations or hypotheses

Observation: Eagles, swallows, and robins

have feathers

Hypothesis: All birds have feathers

Deductive Logic

Drawing a specific conclusion based on a

generalization

Generalization - Birds have feathers

Example - Eagles are birds

Conclusion - Eagles have feathers

Role of Experiments

Used to study a phenomenon under known conditions

Allows you to predict what will happen if a hypothesis is not wrong

Can never prove a hypothesis 100% correct

Scientific Theory A hypothesis that has been tested for its

predictive power many times and has not yet been found incorrect; based on Evidence- facts or information holding an idea to be valid

Valid-quality of being logically or factually sound

Has wide-ranging explanatory power Darwin’s theory of evolution by natural selection

Does not contain bias- favor of or against one thing

Law Notes only that something happens, happens

consistently and across the universe; usually simply stated; frequently can be stated mathematically.

Example: Newtons 2nd Law: F = ma

• A body of mass (m) subject to a force (F) undergoes an acceleration (a) that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass.

What is pure and applied science? Pure Science

Answers questions about phenomena and mechanisms in the natural world.

Why do you do it?• Because we wanted to know!

EX. Studying the ICE MAN

Applied Science Application of scientific knowledge to

practical problems. Why do you do it?

• To fight disease, identify criminals, learn how to store hazardous wastes…etc.

Making Decisions in Science

GRAPHING TERMS

Positive Relationship- when both variables increase.

Negative Relationship- when the variables are inverse to one another.

Mathmatical terms