What is Biology? Biology is the study of life (bios = “life”; logia = “the study of”)...
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Transcript of What is Biology? Biology is the study of life (bios = “life”; logia = “the study of”)...
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
What is Life?
• Life is a characteristic shared by ‘objects’ with self-sustaining biological processes
• All living things share these characteristics:1. Organization2. Metabolism (growth and development)3. Reproduction4. Interaction/response to their environment5. Evolutionary adaptation6. 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
EcosystemFlorida coast
CommunityAll organisms onthe Florida coast
PopulationGroup of brown
pelicans
Nucleus
Nerve
Spinal cord
CellNerve cell
TissueNervous tissue
OrganBrain
OrganelleNucleus Molecule
DNA
Atom
Organism Brown pelican
Organ systemNervous 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 that occurs over a long
period of 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
6. Genetic component (DNA)
• All living organisms have DNA as their genetic blueprint
• DNA = deoxyribonucleic acid• Every cell uses DNA as its genetic
information to provide all structural and functional characteristics of the organism
• Every species has its own unique DNA blueprint.
Three Domains of Life
• Organisms can be grouped into three domains• Scientists classify organisms into a hierarchy of
groups in order to manage the great diversity of life for study– Grouped by fundamental characteristics– 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
Prokaryote = no nucleus; genetic material ‘loose’ in cell
Eukaryote = genetic material stored in a nucleus
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– Homo sapiens
Scientific Name
• Why all the fuss? Common names can be deceiving…
“bear”
“bear”
Scientific Method
• A systematic approach to understand the natural world– Observation– Hypothesis (educated guess based on observation
and previous scientific knowledge)• must be testable
– Experimentation• must be repeatable in order to confirm results are
not occurring by chance– Conclusion
• supports or rejects the hypothesis