Chapter 1 Exploring Life

Biologists Explore Life From the Microscopic to the Global ScaleEvelyn GrahamBetty Orr Katelyn Gibbs Hannah Rousseau

A Hierarchy of Biological OrganizationThe BiosphereEcosystemsCommunitiesPopulationsOrganismsOrgansTissuesCellsOrganellesMolecules

A Closer Look at EcosystemsEvery species within an

ecosystem works with each otherProducersConsumersDecomposersEnergy moves through an

ecosystem entering as light and leaving as heat

A Closer Look at CellsA cell can perform all activities required

for lifeChromosomes are in cells which are

partly made of DNA and DNA is the substance of genes

DNA is in the shape of a double helix and each link of the chain between a double helix is one of four kinds of nucleotides and tells what a cell should do

The genetic instructions are called a genome

Two Main Forms of CellsEukaryotic Cell- nucleus is the

largest organelle and it contains the DNA and other organelles are located in the cytoplasm

Prokaryotic Cell- DNA is not separated from the rest of the cell and prokaryotic cells lack kinds of membrane enclosed organelles

Biological systems are much more than the sum of their partsLaci ReynoldsAndrew ClarkJake RossHarley Hakert

The Emergent Properties of Systems Emergent Properties are due to the

arrangement and interactions of parts as complexity increases.

For example, if a serious head injury disrupts the intricate architecture of a human brain, the mind may cease to function properly even though all of the brain parts are still present. Our thoughts and memories are emergent properties of a complex network of nerve cells.

Emergent Properties are neither supernatural nor unique to life.

The Power and Limitations of ReductionismDisrupting a living system interferes with the

meaningful understanding of its processes. On the other hand, something as complex as an organism or a cell cannot be analyzed without taking it apart.

Reductionism is reducing complex systems to simpler components that are more manageable to study.

For example by studying the molecular structure of DNA that have been extracted from cells, James Watson and Francis Crick inferred, in 1953, how this molecule could serve as the chemical bases of inheritance.

Systems BiologySystems Biology is to model the

dynamic behavior of whole biological systems.

The basic idea of systems biology is simple, the practice is not. It has taken 3 research developments to bring systems biology within reach. High-throughput technology, Bioinformatics, and Interdisciplinary research teams.

Feedback Regulation in Biological SystemsA kind of supply-and-demand

economy applies to some of the dynamics of biological systems.

Negative Feedback, in which accumulation of an end product of a process slows that process.

Positive Feedback, in which an end products speeds up its production.

Biologists explore life across its great diversity of species

Grouping Species: The Basic IdeaTaxonomy is the branch of

biology that names and classifies species. The idea of taxonomy is grouping different species into broader groups.

The broadest units of classification are Kingdoms and Domains and the smallest group of classification are Species and Genus.

The Three Domains of LifeThe kingdoms of life are classified into

three high levels of classification:◦Bacteria ◦Archaea◦Eukarya

Bacteria and Archaea both consist of prokaryotes, prokaryotic cells lack nuclei.

Eukarya consists of eukaryotes, eukaryotic cells have a distinct nucleus.

Exploring Life’s Three DomainsDomain Bacteria:

◦Bacteria are the most diverse and widespread.

Domain Archaea: ◦Archaea live in the Earth’s most

extreme environments. Domain Eukarya:

◦Eukaryatic cells are found in kingdoms such as; plantae, fungi, animalia.

Unity in the Diversity of LifeAs diverse life is, there is also

evidence of remarkable unity, especially at the molecular and cellular levels.

Examples are the universal genetic language of DNA and cell structure.

EvolutionEvolution: Accounts for life’s unity and diversity

Natural Selection

Natural Selection: Survival of the fittest.

The tree of lifeDifferent species with common

ancestry

Evolution

Evolution: All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today.

1.5 Biologists Use Various Forms of Inquiry to Explore LifeBrady MeinrodMikaela ThomasCaity BeddesMcKade Hall

Science is a Way of KnowingInquiry is a search for information

and explanation, often focusing on specific questions.

The two main processes of scientific inquiry is Discovery Science and Hypothesis-Based Science.

Discovery Science Discovery Science describes

natural structures and processes as accurately as possible through careful observation and analysis of data.

Discovery Science is about describing nature.

Important conclusions are based on a type of logic called inductive reasoning.

Hypothesis-Based ScienceHypothesis-Based Science is

about explaining nature.Inquiry usually involves the

proposing and testing of hypothetical explanations.

A hypothesis is a tentative answer to a well-framed question—an explanation on a trial.

Limitations of ScienceHypotheses must be testable and

falsifiable and observations and experimental results must be repeatable.

Theories in ScienceA scientific theory is much

broader in scope than a hypothesis.

A theory is general enough to spin off many new, specific hypotheses that can be tested.

Theories are generally supported by a much more massive body of evidence.

Model Building in ScienceScientific models can take many

forms, such as diagrams, graphs, three-dimensional objects, computer programs, or mathematical equations.

Science, Technology, and SocietyTechnology generally applies

scientific knowledge for some specific purpose. The direction that technology takes depends on the current needs and wants of people and on the social environment of the times.

A set of themes connects the concepts of biology

Tiffany JacksonCody BarnettJessica Caldwell

Biology is Complex!!An interdisciplinary science that

requires knowledge of chemistry, physics, and math.

Its most connected to the humanities and social sciences.

Biology is Expanding!!New discoveries are being made

every day.It is to much to memorize.

The CellThe basic unit of structure in every organism.-Prokaryotic~bacteria~archaea-Eukaryotic~protists~plants~fungi~animals

Heritable InformationLife depends on DNA, the

encoded information that passes on to offspring.

-Encoded in the nucleotide.

Emergent Properties of Biological Systems

The Living world has a hierarchical system

-Extends from Molecules to the BiosphereEach level upward is more complex and interwoven

RegulationFeedback mechanisms regulate biological systems

Interaction with the EnvironmentOrganisms and the environment continually exchange materials and energies

Energy and LifeAll organisms work, which requires energyAll energy originates from the sun

Unity and DiversityThe three groups of life are;

-bacteria-archaea-eukarya

All life is diverse, but are united within the biosphere

EvolutionBiology’s main themeDarwin’s theory of natural selection

-the ability to adapt successfully to the environment

Structure and FunctionForm and function are correlated at all levels of biological organization

Scientific InquiryScience includes observation based discovery and the testing of explanations through hypothesis-based inquiry

Science, Technology and Society

Technologies are goal oriented applications of scienceThey are all interconnected and related