Introduction to Biology Studying Life’s Diversity and Intricate Processes

Introduction to BiologyIntroduction to Biology

Studying Life’s Diversity and Studying Life’s Diversity and Intricate ProcessesIntricate Processes

Biological InquiryBiological Inquiry

Bio = of living thingsBio = of living things

Biological Science: observation, identification, Biological Science: observation, identification, experimental investigation and theoretical experimental investigation and theoretical explanation of natural phenomenaexplanation of natural phenomena

What are the Characteristics of Living Things? What are the Characteristics of Living Things?

What are Fundamental Concepts that Relate to What are Fundamental Concepts that Relate to these Characteristics? these Characteristics?

How Do Biologists Study Living Things?How Do Biologists Study Living Things?

What are common What are common characteristics of living things?characteristics of living things?

Properties of Life Properties of Life organization involving cellsorganization involving cellsenergy use and metabolism energy use and metabolism response to environmental changesresponse to environmental changesregulation and homeostasisregulation and homeostasisgrowth and developmentgrowth and developmentreproduction reproduction biological evolutionbiological evolution

Concept: New Properties Emerge at Concept: New Properties Emerge at Each Level in the Biological HierarchyEach Level in the Biological Hierarchy

Principle of Emergent PropertiesPrinciple of Emergent PropertiesNew characteristics arise out New characteristics arise out

of the arrangement and of the arrangement and interactions of the components interactions of the components of a complex system of a complex system (whole > sum of the parts) (whole > sum of the parts)

organization

Organizational Hierarchy of LifeOrganizational Hierarchy of LifeMost Most ComplexComplex

LeastLeastComplexComplex sub-atomic particlessub-atomic particles

atomatommoleculemoleculemacromoleculemacromoleculeorganelleorganellecellcelltissuetissueorganorganorgan systemorgan systemorganismorganismpopulationpopulationcommunitycommunityecosystemecosystembiospherebiosphere

protons, neutrons, electronsprotons, neutrons, electronsnitrogennitrogennucleotidenucleotideDNADNAnucleusnucleusneuronneuronnervous tissuenervous tissuebrainbrainnervous systemnervous systemfishfishschool of fishschool of fishcoral reef populationscoral reef populationscoral reef (living + nonliving)coral reef (living + nonliving)inhabitable regions of earthinhabitable regions of earth

We’re Here to Train Your Brain!

Complex ideas involve connections between

many neurons

Learning difficult concepts causes new neurons to form

Learning builds and maintains healthy neurons

One of your healthy and well-connected

neurons after Bio 21!

Concept: Cells are an Organism’s Basic Concept: Cells are an Organism’s Basic Units of Structure and Function.Units of Structure and Function.

Two types of cellsTwo types of cellsProkaryoticProkaryotic

Archaea and BacteriaArchaea and Bacteria few internal membranesfew internal membranes no membrane-bound nucleusno membrane-bound nucleus

EukaryoticEukaryotic Protists, Fungi, Animals, PlantsProtists, Fungi, Animals, Plants extensive internal membranesextensive internal membranes membrane-bound nucleusmembrane-bound nucleus

organization

Concept: Structure and Function are Correlated Concept: Structure and Function are Correlated at all Levels of Biological Organization.at all Levels of Biological Organization.

How is red blood cell structure suited How is red blood cell structure suited to its function of carrying oxygen? to its function of carrying oxygen?

organization

Energy Use and Metabolism

Energy = ability to do workEnergy = ability to do work Energy conversion = change Energy conversion = change

of one form of energy to of one form of energy to another another

Metabolism = sum of Metabolism = sum of chemical reactions in an chemical reactions in an organismorganism

Heterotrophic: other feederHeterotrophic: other feeder taking in organic molecules taking in organic molecules

produced by other organismsproduced by other organisms Autotrophic: self-feederAutotrophic: self-feeder

photosynthesis = using the photosynthesis = using the energy of the sun to produce energy of the sun to produce organic moleculesorganic molecules

Concept: The Continuity of Life is Based Concept: The Continuity of Life is Based on Heritable Information in DNA.on Heritable Information in DNA.

The molecule of heredity = The molecule of heredity = DNA = DNA = ddeoxyriboeoxyribonnucleic ucleic aacidcid

reproductionregulation

Per 23 chromosomes

Now estimated at 30,000

genesProteome: all

proteins produced in a cell or organism

Genome: complete genetic

composition of an organism

Genomes and Proteomes reveal evolutionary relationships


Nuclear division reducing the chromosome

number, leading to sperm or eggs

Nuclear division

retaining the original

chromosome number


Growth = increase in sizeGrowth = increase in sizeDevelopment = change in characteristicsDevelopment = change in characteristics

growth and development

Concept: Feedback mechanisms Concept: Feedback mechanisms regulate biological systems.regulate biological systems.

Concept: Feedback mechanisms Concept: Feedback mechanisms regulate biological systems.regulate biological systems.

Living things maintain Living things maintain homeostasishomeostasis = a relatively stable internal condition= a relatively stable internal condition

regulation and homeostasisresponse to environmental changes

Plant Responses to Sunlight

Alfalfa leaves oriented Alfalfa leaves oriented toward sunlight to toward sunlight to maximize photosynthesismaximize photosynthesis

Desert plant leavesDesert plant leavesoriented verticallyoriented verticallyto minimize water lossto minimize water loss

http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/tropisms.html

response to environmental changes

http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/tropisms.html

Concept: Evolution Accounts for Concept: Evolution Accounts for the Unity and Diversity of Lifethe Unity and Diversity of Life

Two mechanisms of evolutionary changeTwo mechanisms of evolutionary changeVertical Descent with Mutation: through Vertical Descent with Mutation: through

changes in DNA, new species arise changes in DNA, new species arise from pre-existing species from pre-existing species

Natural Selection: individuals with traits Natural Selection: individuals with traits that provide an advantage in the that provide an advantage in the current environment are more likely to current environment are more likely to survive and reproducesurvive and reproduce

response to environmental changesbiological evolution


Vertical Descent with MutationVertical Descent with Mutation


Natural Selection leads to a change Natural Selection leads to a change in the genetic characteristics of a in the genetic characteristics of a population population evolution evolution

Adaptation = characteristic that Adaptation = characteristic that promotes survival and reproductionpromotes survival and reproduction

The Unity and Diversity of Living ThingsThe Unity and Diversity of Living Things

An Evolutionary Tree of LifeAn Evolutionary Tree of Life

The Three The Three DomainsDomains of Life Represent the Earliest of Life Represent the Earliest Branches in Evolutionary HistoryBranches in Evolutionary History

Contains multiple

kingdoms

How Do Biologists Study Living Things?How Do Biologists Study Living Things? Discovery ScienceDiscovery Science Collect Collect DataData without a pre-stated without a pre-stated

hypothesishypothesis Make Make ObservationsObservations = objective = objective

notations of a phenomenonnotations of a phenomenon Can lead to formulation of Can lead to formulation of

hypotheseshypotheses Example: determine how many Example: determine how many

amphibian species are present in a amphibian species are present in a specific environmentspecific environment

How Do Biologists Study Living Things?How Do Biologists Study Living Things? Hypothesis-based ScienceHypothesis-based Science Ask Ask QuestionsQuestions or make or make ObservationsObservations Formulate an Formulate an HypothesisHypothesis: tentative : tentative

answer to well-framed question answer to well-framed question Make Make PredictionsPredictions based on hypothesis based on hypothesis Test Predictions by Conducting Test Predictions by Conducting

ExperimentsExperiments Analyze experimental dataAnalyze experimental data Determine whether data supports Determine whether data supports

hypothesishypothesis

How Do Biologists Study Living Things?How Do Biologists Study Living Things? Biology 21 Definition Biology 21 Definition

•An Hypothesis will have An Hypothesis will have

– Two measurable variables Two measurable variables – Precise relationship between them Precise relationship between them

(relationship = prediction)(relationship = prediction)

The relationship between DNA content and length of

the cell cycle is a direct proportion.


A good hypothesis is A good hypothesis is TestableTestable

experiments can be designed to test experiments can be designed to test predictions from the hypothesispredictions from the hypothesis

experimental results must be experimental results must be repeatablerepeatable

Falsifiable Falsifiable allows scientists to eliminate allows scientists to eliminate

alternative hypothesesalternative hypotheses


•Testing hypothesesTesting hypotheses– Controlled ExperimentControlled Experiment

• test designed to determine the effect of test designed to determine the effect of one factor while keeping all other factors one factor while keeping all other factors constantconstant

• experimental = sample treated to test for experimental = sample treated to test for effect of the factor being studiedeffect of the factor being studied

• control = sample treated like experimental control = sample treated like experimental in all ways EXCEPT for the factor being in all ways EXCEPT for the factor being studiedstudied

Use of a Controlled ExperimentUse of a Controlled Experiment

Increasing dose of almonds on subjects with hyperlipidemia. Increasing dose of almonds on subjects with hyperlipidemia. Full almond = 73 grams/dayFull almond = 73 grams/dayControl = whole wheat muffins (>5% saturated fat)Control = whole wheat muffins (>5% saturated fat)Half almond = half dose almond + half dose muffinsHalf almond = half dose almond + half dose muffinsAll supplements provided equal amounts of energy in the diet.All supplements provided equal amounts of energy in the diet.Jenkins, et al., 2002, Jenkins, et al., 2002, Circulation Circulation 106:1327 106:1327

How Do Biologists Study Living Things?How Do Biologists Study Living Things? • Supported HypothesesSupported Hypotheses•Theory = broad explanation of a natural Theory = broad explanation of a natural phenomenon that has been supported by phenomenon that has been supported by a large body of evidencea large body of evidence•Principle or Law = theory that has been Principle or Law = theory that has been supported over a long period of timesupported over a long period of time– Cell PrincipleCell Principle• All living things are composed of cells and cell All living things are composed of cells and cell

products; all cells come from pre-existing cells.products; all cells come from pre-existing cells.

– Principle of EvolutionPrinciple of Evolution– Principle of Emergent PropertiesPrinciple of Emergent Properties

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Introduction to Biology Studying Life’s Diversity and Intricate Processes