Principles of Biology BIO 101 Prof. Marianne E. McNamara

Who Are You? Your major Your year/are you part time or full time Your plans Your interests

What is Biology? Biology is the study of life (bios = “life”; logia = “the study of”) Biology consists of several specialized disciplines –Botany: the study of plants –Zoology: the study of animals –Microbiology: the study of microorganisms

Why Study Biology??? It’s EVERYWHERE!

Why Study Biology??? Biology frequently plays a role in dealing with various challenges that face society

Why Study Biology??? It’s AWESOME!!!

Why Study Biology??? Biology is the scientific study of life!

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What is the definition of life? Life is a characteristic shared by ‘objects’ with self-sustaining biological processes All living things share these characteristics: –Organization –Metabolism (growth and development) –Reproduction –Interaction/response to their environment –Evolutionary adaptation –Genetic component (DNA)

1. Organization All living things are organized Life is organized in a hierarchical fashion –Hierarchy: any system of things ranked one above another

Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Nucleus Nerve Spinal cord Cell Nerve cell Tissue Nervous tissue Organ Brain Organelle Nucleus Molecule DNA Atom Organism Brown pelican Organ system Nervous system Brain Hierarchy of Life Ecosystem Community Population Organisms Systems Organs Tissues Cells Molecules Atoms Level

2. Metabolism All living things metabolize Metabolism = set of chemical reactions necessary to maintain life –Metabolism is management of ENERGY; organisms TAKE energy from their environment, transform and use it –Allows organisms to grow, reproduce, maintain structural stability, and respond to their environments

Metabolism Autotrophs – transform energy from their environment (the “producers”) –Plants are autotrophs; they transform the sun’s energy into energy-rich molecules that support life Heterotrophs – ingest their energy from their environment (the “consumers”) –Animals are heterotrophs; they ingest (eat) food to obtain energy-rich molecules

3. Reproduction All living things reproduce Reproduction can be sexual, asexual, or both!

4. Interaction/response to environment All living things interact and respond to their environment Living things respond to environmental stimuli (scent, sight, sound, touch, taste) Living things exchange gases (carbon dioxide, oxygen, etc) with their environment

Environmental interaction A Venus flytrap responds to the stimulus of a dragonfly landing on it

5. Evolutionary adaptation All living things evolve Evolution is a gradual change over a long period of time (most of the time!) Evolution explains the diversity and adaptations of life Evolution is the change in genetic material of a population of organisms from one generation to the next (we’ll come back to this)

6. Genetic component (DNA) All living organisms have DNA as their genetic blueprint DNA = deoxyribonucleic acid Every cell uses DNA as its genetic information Every species has its own unique DNA sequence.

Three domains of life Organisms can be grouped into three domains Scientists classify organisms into a hierarchy of groups –Grouped by fundamental characteristics –Helps scientists manage the great diversity of life for study –Not always clear-cut; organisms do not always fall into structured categories

Three domains of life All organisms are grouped into three domains –Domain Archea –Domain Eubacteria –Domain Eukarya Eukaryote = genetic material stored in a nucleus Prokaryote = no nucleus; genetic material ‘loose’ in cell Prokaryotic Eukaryotic

Classification Domains are further classified/categorized into: –Kingdom –Phylum –Class –Order –Family –Genus –Species

Domain Kingdom Phylum Subphylum Class Order Family Genus Species Diversification

Scientific name Organisms are ultimately sorted to the species level (species that appear to be closely related are grouped into the same genus_ Binomial (“two part”) system: genus and species constitute the scientific name of the organism Genus is always Capitalized and species is always lower-case; both are in italics

Scientific name Why all the fuss? Common names can be deceiving… “bear” “dolphin”

Scientific name Scientific names are descriptive May describe unique characteristic, region where species is found, etc. Example: Humpback whale Megaptera novaeangliae –Magas = large –Pteron = wing –Novas = new –Angaliae = England

Scientific Method A systematic approach to understand the natural world –Observation –Hypothesis Must be testable –Experimentation Must be repeatable Multiple trials necessary –Conclusion Supports or rejects the hypothesis

Hypotheses can never be proven!!!