Transcript Diversity of Living Things

Taxonomy
• The study of the
classification of living things
• Taxa – group of one or
more groups of organisms
• SIX hierarchical levels of
Increasing
classification
1.
2.
3.
4.
5.
6.
7.
8.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
similarity
EUKARYA Most Inclusive
ANIMAL
CHORDATA
MAMMALIA
PRIMATES
HOMINIDAE
Increasing
HOMO
diversity
SAPIENS Least Inclusive
Binomial Nomenclature
• Carolus Linnaeus
(1700’s)
• System for
naming and
classifying species
• Two
characteristics
1. Genus
2. Species
• Used by all
countries in all
languages to
avoid confusion
among scientists.
– Homo sapiens
– Canus lupus
– Felis domesticus
Proper Way of Naming
• Three ways to properly
name and classify an
organism
1. All Italics - capital letter
of first name followed by
lower case letter
Tamiasciurus hudsonicus
2. Italics - capital letter
followed by period (.) and
then lower case letter
italics
T. hudsonicus
1. Handwritten - always
underline the name
Tamiasciurus hudsonicus
Group organisms with increasing similarities
Common Name
Family
Scientific Name
Red squirrel
Sciuridae
Tamiasciurus hudsonicus
Short-tail weasel
Mustelidae
Mustela erminea
Groundhog
Sciuridae
Marnota monax
Mink
Mustelidae
Mustela vison
Eastern chipmunk
Sciuridae
Tamias striatus
River otter
Mustelidae
Lutra canadensis
Fisher
Mustelidae
Martes pennanti
Muskrat
Cricetidae
Ondatra zibethica
Black-footed ferret
Mustelidae
Mustela nigripes
Dichotomous Key
• Tool used by biologists to
identify an unknown organism
• Series of paired statements of
anatomical description that
leads to an identification.
Key for Vertebrate Identification
1. a) animal has a spine…………………..go to 2
b) animal has no spine………..…invertebrate
2. a) animal has no gills and fins……..…. go to 3
b) animal has gills and fins…………….. Fish
3. a) animal has no scales…………..........go to 4
b) animal has scales………………..….reptile
4. a) animal has feathers …………………..bird
b) animal has no feathers ……………..go to 5
5. a) animal has hair…………………….mammal
b) animal has no hair………………..amphibian
Three Domain Classification System
• Based on
– DNA analysis,
Evolutionary history,
Relationship among
organisms
Include
1. Bacteria (Prokaryotes)
A.
B.
C.
D.
2.
Archaea (Prokaryotes)
A.
B.
C.
D.
3.
Gram positive
bacteria
Spirochetes
Chlamydia
Cyanobacteria
Extremeophiles
Halophiles
Methanogens
Thermophiles
Eukarya (Eukaryotes)
A.
B.
C.
D.
Protista
Fungi
Plants
Animals
Major Features of The Three Domains
Bacteria, Acrchaea, and Eukaryotes
Feature
Bacteria
Archaea
Eukaryotes
Membrane-enclosed organelles
Absent
Absent
Present
Peptidoglycan in cell wall
Present
Absent
Absent
RNA polymerase
One Type
Several Kinds
Several Kinds
Introns (noncoding regions of genes)
Absent
Present in
some genes
Present
Not inhibited
Not inhibited
Antibiotic sensitivity to streptomycin, Inhibited
chloramphenicol
Domain Bacteria
• Lacks a nucleus and other
membrane bound organelles
• Contain ribosomes
• Pili – hair like structures used to
attach to other cells or objects
• Flagellum – tail like extension
for motorboating (propeller)
• Cell wall
• Nucleoid – chromosomal DNA
• Plasmids – small circular pieces
of DNA
• Capsule – composed of
polysaccharides, protects cell
against phagocytosis
Bacteria are Pathogens
•
•
•
•
Klebsiella pneumoniae
Clostridium difficile
Escherichia coli
Staphylococcus aureus
– MRSA
• Streptococcus pyogenes
– Flesh eating disease
Common Shapes of Prokaryotes
• Coccus (Round)
– N. meningitidis – meningitis
• Bacillus (Rod)
– B. anthracis - anthrax
• Diplococci (Pair)
– N. gonorrhoea – gonorrhoea
• Streptococci (Chain)
– S. pyogenes – scarlet fever
• Spirochete (Spiral)
– T. pallidum – syphilis
Bacteria
• Cell walls are composed of peptidoglycan
• Reproduce Asexually via binary fission
• Make energy using organic chemicals, inorganic chemicals, or
photosynthesis
•
•
•
•
Lack peptidoglycan in cell wall
Reproduce via Binary Fission
Live in extreme environments
Methanogens
– Live in environments that lack
oxygen
– Produce methane gas
– Live in landfills
• Extreme halophiles
– Live in environments that love
salt
– Dead Sea, Great Salt Lake
• Extreme thermophiles
– Live in environments of extreme
heat
– Volcanic vents deep in the ocean
Archaea
Binary Fission
• Asexual
Reproduction
Conjugation
• Transfer of
genetic material
between bacterial
cells
• Creates genetic
diversity
• Antibiotic
resistance
Domain Eukarya
•
•
•
•
Protista
Fungi
Plantae
Animalia
Animal-like Protists
• Sporozoans
– Cannot move on their own
(nonmotile)
– Reproduce both sexually
(gametes) and asexually
(mitosis)
– Parasites
– Transmitted through vectors
(insects)
• Plasmodium vivax
– Causes malaria (most common)
– Transmitted by female
anopholes (mosquito)
Plasmodium vivax
• Mosquito bites
– Infects human with
sporozoites
• Sporozoites infect liver
cells
– Develop into merozoites
• Merozoites infect RBC’s
– Continue to infect RBC’s
– Some develop into
gametocytes
• Mosquito bites infected
human
– Gametocytes fertilize,
develop into oocyst
• Oocyst ruptures
releasing sporozoites
Plant-like Protists (Algae)
• Eukaryotes
• Cellulose cell walls
• Use photosynthesis for
energy (primary
producers)
• Produce molecular
oxygen and organic
compounds
Plant-like protists
• Dinoflagellates
– Marine plankton (flagella)
– Red tide
• Algal blooms produce dinotoxins
• Toxic to humans
• Diatoms
– Phytoplankton
– Cell wall is made up silica
• Euglenoids
– Contain chloroplasts
– Also feed by phagocytosis
• Green Algae
– Macroscopic seaweeds
• Eukaryotes
• Chitin cell walls
• Use organic chemicals for energy
(consumers/heterotrophs)
• Decomposers (important in
ecosystems)
• Moulds
– consist of masses of mycelia,
which are composed of filaments
called hyphae
– Reproduce asexually (spores)
• Yeasts
– Round shape
– Reproduce asexually (budding)
Fungi
Yeast Reproduction
• Budding
New organism
develops from
outgrowth on
another cell at
a particular
site
• Ascus
Spore bearing
cell in fungi
Plantae (Eukaryotes)
• All are autotrophic (make own food)
– Synthesizing organic molecules using photosynthesis
– Immobile
• 10 divisions of plants
• Characteristics of Plants include
– Vascular tissue
– Cone bearing
– Flowering
– Mosses,
– Ferns
Animalia (Eukaryotes)
•
•
•
•
All are Heterotrophic
Multicelluar
Grouped into 35 phyla
Most reproduce sexually
(diploid stage)
• Most species – sperm
fertilizes egg
• Monophyletic
– All animal lineages
can be traced back to
a single common
ancestor
– Classified by
anatomical features
Classification of Animalia
• Organisms are
classified and identified
using 6 characteristics
1. Structural
– anatomy and physiology
2. Biochemical
– enzymes, proteins, DNA
3. Cytological
– cell structure
4. Embryological
– development
5. Behavioral
– patterns of actions
6. Fossil
– common ancestor