introduction: the science of biology. characteristics of living things biology – the study of...
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Introduction: The Science of Biology
Characteristics of Living Things Biology – the study of life. All life has 7 unifying characteristics:
A. Cells (organization) 1. the basic building blocks of life
2. organelles – small structures that perform
specific functions w/in the cell
3. An organisms “body type” can be: a. unicellular – consists of a single cell b. multicellular – combine & functions together
“Cell Types”Prokaryotic -simple-no nucleus
Eukaryotic-complex-has a nucleus
B. Obtain & Use Energy 1. All organisms need to obtain & use large amounts of energy to fuel chemical reactions 2. Metabolism – the sum of all processes &
chemical reactions in an organism
3. What is the ultimate source of Energy? How is this energy utilized?
PhotosynthesisSUN
Heterotroph – need to consume food toobtain energy
Autotroph – produces its own food. Obtains its energy directly from the sun
C. Homeostasis1. the maintenance of internal conditions;
controlled by nervous system and hormones2. metabolism works only when internal
conditions are steady & stable
D. Response to Stimuli 1. homeostasis works only when organisms interact & respond to environment & surroundings
2. organisms must make proper adjustments in order to maintain homeostasis & regulate metabolism Ex. foraging, migration, sweating, shivering
E. Regulated Growth & Development
1. the end result of metabolism
2. Growth = increase in size Development = change & differentiation
3. carefully controlled growth leads to normal adult shape & function uncontrolled growth destroys life (ex. cancer)
F. Reproduction 1. necessary to produce offspring in order to continue the species
2. two kinds:
a. asexual – 1 parent; genetically identical offspring
(simply split in two; binary fission)
b. sexual – 2 parents; joining of an egg and sperm during fertilization. Get genetic variationDIVERSITY
G. Adaptation & Evolution
1. reproduction often involves genetic variation, organisms will inherit traits that enhance their survival & reproductive success in an environment
2. Natural selection chooses organisms that can “adapt” to changes so they can function; these organisms are more fit & likely to survive
“Survival of the Fittest”
3. SO, the diversity we see in life is a result of adaptaton organisms “change over time” and thus evolve…
* All living things share these 7 basic characteristics
* This unity suggests that all life descended from a common ancestor.
* However, the diversity of life suggests that the evolution from this common ancestor has been a Descent with Modification making adaptations to different environments and ways of life
Why Do We Classify Organisms? Biologists group organisms to represent
similarities and proposed relationships. Classification systems change with
expanding knowledge about new and well-known organisms.
Placing organisms into domains and their subdivisions is a classification scheme that indicates the evolutionary relationships of the organisms being studied.
Helpful to have a universal system to group these organisms.
Tacitus bellus
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II. Classification of Living Things
Leucaena leucocephala Lead tree
ClassificationTaxonomy
discipline to classify organisms according to similar features and assign each organism a universally accepted name
Binomial NomenclatureTwo part name (Genus, species)
Hierarchical ClassificationSeven Taxonomic Categories
(DKPCOFGS)
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Carolus von Linnaeus(1707-1778)
Swedish scientist who laid the foundation for
modern taxonomy
Binomial NomenclatureCarolus von Linnaeus Two-word naming systemHomo sapiens
Genus (Homo)Noun, Capitalized,
Underlined or ItalicizedSpecies (sapiens)
Descriptive, Lower Case, Underlined or Italicized
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Hierarchical ClassificationTaxonomic categories
Domain DashingKingdom KingPhylum PhilipClass CameOrder OverFamily ForGenus GreenSpecies Soup
Organisms can only be members of thesame species of they can reproduce w/each other to produce fertile offspring
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Taxonomic
Classification
Blue Tang Yellow Tang
Kingdom Animalia Animalia
Phylum Chordata Chordata
Class Actinopterygii Actinopterygii
Order Perciformes Perciformes
Family Acanthuridae Acanthuridae
Genus Paracanthurus Zebrasoma
Species P. hepatus Z. flavescens
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Taxonomic
Classification
Blue Tang Percula Clownfish
Kingdom Animalia Animalia
Phylum Chordata Chordata
Class Actinopterygii Actinopterygii
Order Perciformes Perciformes
Family Acanthuridae Pomacentridae
Genus Paracanthurus Amphiprion
Species P. hepatus A. percula
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Taxonomic
Classification
Blue Tang Great White Shark
Kingdom Animalia Animalia
Phylum Chordata Chordata
Class Actinopterygii Chondrichthyes
Order Perciformes Lamniformes
Family Acanthuridae Lamnidae
Genus Paracanthurus Carcharodon
Species P. hepatus C. carcharias
Ex. Human Taxonomy
Domain:Kingdom:Phylum:Class:Order:Family:Genus:Species:
Eukarya (has a nucleus)Animalia (multicelluar heterotroph)Chordata (have a backbone)Mammalia (have hair, mam. glands)Primates (large brains; intelligent)Hominidae (walk upright on 2 legs)
Homo (man)sapiens (wise)
Kingdoms and Domains
Bacteria Archaea Eukarya
Bacteria Archaea Protista Plantae Fungi Animalia
Monera Protista Plantae Fungi Animalia
The three-domain system
The six-kingdom system
The traditional five-kingdom system
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(prokaryotes)
NO LONGER USED
Eubacteria•Prokaryotic•Unicellular•Cell Wall with peptidoglycan •Autotrophic (photosynthesis or chemosynthesis) or Heterotrophic•Can be beneficial or pathogenic
Archaebacteria•Discovered in 1983
•Scientists took samples from a spot
deep in the Pacific Ocean where hot
gases and molten rock boiled into the
ocean form the Earth’s interior.
•Prokaryotic cells
•unicellular
•Contain adaptations to extreme
environments (Lack of oxygen,
extreme temps, high acidity)
•Autotrophic or Heterotrophic
•Cell wall (NO peptidoglycan)
Domain Eukarya contains….Kingdom Protista
Kingdom Fungi Kingdom Plantae
Kingdom Animalia
ProtistaEukaryotic“mis-fits” do not fit the definition of a plant, animal, or fungi.Algae, protozoans, and slime molds Unicellular
A few exceptions: Some are multicellular (algae)
Some have cell walls, not all
PlantaeEukaryoticMulticellularCell walls that contain celluloseAutotrophic
photosynthesismosses, ferns, conifers, and flowering
plants
FungiEukaryotic Mostly multicellular
Exception: yeast is unicellularHeterotrophic
Decomposers – break down
dead organisms and absorb their foodCell Wall composed of chitinYeast, mold, mushroomsNot capable of photosynthesis
Animalia
EukaryoticMulticellularNO cell wallHeterotrophic
Interesting Animals!
III. Organization of Living Things A. - basic building blocks of matter
B. - atoms bonded togetherC. - basic building block of lifeD. - similar cells performing similar function (ex. Nervous/Brain)E. - different tissues work together (ex. muscle/nervous tissue make up skin)F. - organs working together (ex. stomach, intestines digestive sys.) G. Organisms -- unicellular organisms use organelles
Atoms Molecules
CellsTissues
Organs
Organ system
H. Groups of Organisms 1. – same species living in a particular place at a particular time
2. – different populations that live in same area & interact 3. – a community of living things & the physical env’t4. – groups of ecosystems in a large geographic area 5. – all organisms & their supportive env’ts on the planet
Population
Community
Ecosystem
Biome
Biosphere