Chapter 1 Exploring Life

Biologists Explore Life From the Microscopic to the Global Scale Evelyn Graham Betty Orr Katelyn Gibbs Hannah Rousseau

A Hierarchy of Biological Organization The Biosphere Ecosystems Communities Populations Organisms Organs Tissues Cells Organelles Molecules

A Closer Look at Ecosystems Every species within an ecosystem works with each other Producers Consumers Decomposers Energy moves through an ecosystem entering as light and leaving as heat

A Closer Look at Cells A cell can perform all activities required for life Chromosomes 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 Cells Eukaryotic 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 parts Laci Reynolds Andrew Clark Jake Ross Harley 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 Reductionism Disrupting 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 Biology Systems 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 Systems A 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 Idea Taxonomy 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 Life The 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 Domains Domain 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 Life As 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.

Evolution: Accounts for life’s unity and diversity

Natural Selection Natural Selection: Survival of the fittest.

The tree of life Different 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 Life Brady Meinrod Mikaela Thomas Caity Beddes McKade Hall

Science is a Way of Knowing Inquiry 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 Science Hypothesis-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 Science Hypotheses must be testable and falsifiable and observations and experimental results must be repeatable.

Theories in Science A 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 Science Scientific models can take many forms, such as diagrams, graphs, three- dimensional objects, computer programs, or mathematical equations.

Science, Technology, and Society Technology 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 Jackson Cody Barnett Jessica 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 Cell The basic unit of structure in every organism. -Prokaryotic ~bacteria ~archaea -Eukaryotic ~protists ~plants ~fungi ~animals

Heritable Information Life 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 Biosphere Each level upward is more complex and interwoven

Regulation Feedback mechanisms regulate biological systems

Interaction with the Environment Organisms and the environment continually exchange materials and energies

Energy and Life All organisms work, which requires energy All energy originates from the sun

Unity and Diversity The three groups of life are; -bacteria -archaea -eukarya All life is diverse, but are united within the biosphere

Evolution Biology’s main theme Darwin’s theory of natural selection -the ability to adapt successfully to the environment

Structure and Function Form and function are correlated at all levels of biological organization

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

Science, Technology and Society Technologies are goal oriented applications of science They are all interconnected and related