What is Biology????
• Bio- (life)……..-ology (study of)
• Biology is the fundamental study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy
• Biology is a broad field of science– Can you name some of these subdivisions?
• Subdivisions of biology are recognized on the basis of the scale at which organisms are studied– Biochemistry examines the basic chemistry of life– Molecular Biology studies the interactions of the systems
of biological molecules– Cellular Biology studies the basic building block of life,
the cell.– Physiology examines the physical and chemical functions
of tissues and organ systems– Ecology examines how various organisms interact with
one another and with the environment
*List is not all-inclusive*
Contributors to the Field of Biology
• Hippocrates (Greek Physician)– “Father of Western Medicine”
• Anton von Leeuwenhoek (Dutch Scientist)– “Father of Microbiology”
• Gregor Mendel (Moravian Monk/Scientist)– “Father of Genetics”
• Charles Darwin (English Geologist)– “Father of Evolution”
• Francis Crick and James Watson (Rosalind Franklin)– Deciphered the structure of DNA
Seven Characteristics of Life
1. Cellular Organization—all living organisms consist of one or more cells
2. Ordered Complexity—Living organisms contain many complex molecular structures and systems that are highly ordered
3. Sensitivity—living things all react or respond to stimuli.
4. Growth, Development, and Reproduction—all organisms are capable growing and reproducing. Through reproducing they pass on genetic material to their offspring
5. Energy Utilization—all living things use energy to live and grow
6. Homeostasis—All organisms maintain relatively constant internal conditions that are different from their environment
7. Evolutionary Adaptation—all organisms interact with other organisms and their environment in ways that influence their survival. – “Survival of the Fittest” or “Only the Strong
Survive”– http://www.nature.com/scitable/topicpage/evolut
ionary-adaptation-in-the-human-lineage-12397– “Survival of the Sickest” by Sharon Moalem
Hierarchical Organization
• The organization of the biological world is arranged from smallest to largest. – Each level builds on the level below it (upside
down pyramid)
• There are five levels of hierarchical organization
1. Cellular Level
• At the cellular level, atoms interact to form molecules.
• Complex biological molecules are assembled into organelles.– Organs of a cell
• Organelles are contained within membrane-bound units called cells.
2. The Organismal Level
• Cells, in complex multi-cellular organisms, exhibit different levels of organization– Tissues
• Groups of similar cells that acts as a functional unit
– Organs• Body structures composed of several different tissues
– Organ systems• Multiple organs that work together to complete a function
– Organism• Comprised of the different organ systems working together
3. The Population Level
• Individual organisms can be categorized into several hierarchical levels in the living world– Species
• A particular kind of organism form a species (humans)
– Population• Group of organisms of the same species living in the same
place (humans in Clermont)
– Biological Community• Consists of all the populations of DIFFERENT species living
together in the same environment (all living organisms in Clermont)
4. Ecosystem Level
• The biological community AND the physical habitat (non-living) that the community lives is known as an Ecosystem– Swamps– Deserts– Jungles
5. The Biosphere
• The combination of all ecosystems
• The planet Earth is a Biosphere
• Reductionism—principle of trying to understand a complex system by examining its simple components
Classification and Identification of Life
• Diversity is the hallmark of life– 1.8 million species have been identified– Group organisms according to their similarities
• What drives this diversity????
• DNA analysis divide all organisms into 3 domains– Eukaryotes, Bacteria, and Archaea
• Bacteria and Archaea make up the group Prokaryotes
Taxonomy
Taxonomy—the science of classifying organisms (taxa—categories of organisms)
• Provides a reference for identifying organisms
• Carlos Linnaeus introduced a formal system of classification– Used Latin names to provide a “common”
language for all organisms
Figure 10.1 The Three-Domain System.
BacteriaMitochondria
Cyanobacteria
Chloroplasts
Thermotoga
Gram-positivebacteria
Proteobacteria
Horizontal gene transferoccurred within thecommunity of early cells.
Nucleoplasm grows larger
Mitochondrion degenerates
Giardia
Euglenozoa
Diatoms
Dinoflagellates
Ciliates
AnimalsFungi
Amebae
Slime molds
Plants
Greenalgae
Eukarya
Extremehalophiles
Methanogens
Hyperthermophiles
Origin of chloroplasts
Origin of mitochondria
Archaea
Vertical Gene TransferLateral Gene Transfer
Scientific Nomenclature
• Common names– Vary with languages and with geography– Spanish Moss • Tillandsia usneiodes
• Binomial nomenclature (genus + specific epithet)– Used worldwide– Genus capitalized and species lowercase • Escherichia coli and Homo sapiens
What is Science?
• Science is concerned with developing an increasingly accurate understanding of the world around us using both observation and reasoning– Inquiry—search for information and explanations of
natural phenomena– Data—recorded observations
• Qualitative or Quantitative
• Two types of reasoning1. Deductive Reasoning2. Inductive Reasoning
Deductive vs. Inductive Reasoning
• Deductive starts as a general statement and examines possibilities to reach a conclusion (general to specific)– All men are dogs. Dwayne Johnson is a man. Dwayne
Johnson must be a dog.
• Inductive makes broad generalizations based on specific observations (specific to general)– Shakira is a great dancer. Shakira is Colombian. All
Colombians are great dancers.– Also known as Inference
Scientific Method
• Every scientific discipline is governed by the scientific method.
• Defined as the body of techniques utilized in investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge
• Five steps to the scientific method
5 Steps of the Scientific Method
1. Present a questionWhy did my car not start this morning?
2. Form a hypothesis—a conjecture or belief based on already established information
The car did not start because the battery is “dead”.
3. Make a predictionIf I get a new battery the car will start.
5 Steps of Scientific Method
4. Test your hypothesis (Experiment)Purchase a new battery from Autozone, replace the battery, turn the ignition.
5. Observe results and make an analysisDid the car start? If not, then form another hypothesis
“Control vs. Experimental”Control Experiment have pre-established outcomesand
are used to validate the experimentIndependent vs. Dependent variable