Download Classification

Origin of Life


The early atmosphere probably contained
H2O, CO, CO2, N2, and possibly some
methane CH4, but little or no O2
Volcanic activity, lightning, and UV
radiation were intense
How did Life Originate?

Small organic molecules must have
appeared first

probably happened when inorganic chemicals
were energized by lightning or UV radiation
Stanley Miller Experiment:
Creating Organic Molecules
using Inorganic Molecules

Simulations
of such conditions
have produced
amino acids,
sugars, and
nucleotide bases
Origin of Life:
Heterotroph Hypothesis
Taxonomy: Carolus Linneaus



Invented Modern
Taxonomy in
1700’s.
System called:
Binomial
Nomenclature
Grouped organisms
according to a
hierarchical system
Classification & Subdivisions

Human Classification
Classification: What you need to
know




3 Domains
Main Characteristics of 5 Kingdoms
Something about a few Phyla within the
Kingdoms
The general order in which each evolved
Viruses: Living or Non Living?



Phage = virus
Bacteriophage
= virus with
bacteria host
Virus =
genetic info
with protein
shell
Viruses: Hershey – Chase
Experiment
Viruses: Reproductive Cycle
Lytic vs Lysogenic
Viruses: Retrovirus




HIV: Retrovirus
RNA instead of
DNA
Enzyme reverse
transcriptase
Once in host,
converts RNA
into DNA
(reverse
transcription)
Viruses: Retrovirus

Reverse Transcription
Classification: Domains

Major Division of
Life: Prokaryotes
vs. Eukaryotes
Domain: Archaebacteria

Archaea live in
EXTREME conditions





anaerobic swamps
salt lakes
acidic hot springs
deep-sea
hydrothermal vents
animal digestive
systems
Kingdom MONERA (Bacteria)

Prokaryotes - oldest
life-forms

Remain most
numerous and
widespread
organisms on Earth
today
Kingdom MONERA



Prokaryotic: no
nucleus, no organelles
Single-celled, Contains
double-stranded
circular chromosomal
DNA
Cell wall:
peptidoglycan
Kingdom MONERA: Shapes

Spheres (cocci):
most common

Rods (bacilli)

Curves or spirals
Kingdom MONERA

Cyanobacteria:



Autotrophs
Photoautotrophs and Chemoautotrophs
Bacteria:

heterotrophs
Kingdom MONERA:
Genetic Engineering


Bacteria can reproduce both
asexually (binary fission)
and sexually
This discovery led to the
development of recombinant
DNA technology

a set of techniques for combining
genes from different sources
Kingdom MONERA:
Gene Exchanging


Can occur in 3 ways
Transformation: taking
up of DNA from the fluid
surrounding the cell
DNA enters
cell
Fragment of
DNA from
another
bacterial cell
Bacterial chromosome
(DNA)
Kingdom MONERA:
Gene Exchanging

Transduction:
transfer of bacterial
genes by phage
(virus)
Phage
Fragment of
DNA from
another
bacterial cell
(former phage
host)

Conjugation: union of
cells and the DNA
transfer between them
Kingdom MONERA: Plasmids

Plasmid: a
small circular
DNA molecule
separate from
the bacterial
chromosome
Kingdom MONERA:
Genetic Engineering



Restriction enzymes
cut DNA at specific
points
DNA ligase “pastes”
the DNA fragments
together
The result is
recombinant DNA
Kingdom MONERA:
Recombinant DNA
Kingdom PROTISTA


Simple, eukaryotic, mostly single-celled
Animal – like: Protozoans



Heterotrophs include: amoeba & paramecium
& sporozoans
Fungus Like: slime molds
Plant-like: Autotrophs Algae (only multi
celled), also euglena
Kingdom PROTISTA


Endosymbiotic Theory:
first eukaryotic cells
Mitochondria &
chloroplasts have own
DNA & ribosomes
Kingdom PROTISA:
Protozoans


Amoebas
Heterotrophs, Phagocytosis, Pseudopods.
Cytoplasmic Streaming
Kingdom PROTISTA:
Protozoans

Sporozoans


Animal parasites, disease causing ie: malaria
caused by plasmodium
need two hosts to fully develop
Kingdom PROTISTA:
Protozoan







Ciliates
ex. Paramecium
Heterotrophs
Cilia
Contractile Vacuole
Oral Groove
Binary Fission &
Conjugation
Kingdom PROTISTA:
Plantlike



Phylum Euglena, Diatoms, Algae
Euglena
- Unicellular, photosynthetic
Diatoms

Unicellular, glass-like walls
Kingdom PROTISTA:
Plantlike







Phylum Algae
Photosynthetic
Multicellular
Marine
Diploid Sporophytes
Haploid Gametophytes
Plants probably evolved from one group of algae
Kingdom PROTISTA:
Plantlike


Seaweed multicellular
photosynthetic
organisms -- lack the
xylem / phloem
Examples include



Brown algae
Red algae
Green algae
Kingdom PLANTAE



Multi-celled /
eukaryotic
Autotrophic /
chloroplast
Cell wall - cellulose
Kingdom PLANTAE



Unlike algae, plants have vascular tissue
Internal tubes that transports water and
nutrients throughout the plant body
It provides internal support

Xylem and Phloem
Kingdom PLANTAE
Kingdom PLANTAE

Plant Evolution
Kingdom PLANTAE:
Division Bryophytes



Lack vascular tissue
Mosses, grow low
Need to be near or
in moist area
Kingdom PLANTAE:
Division Fern

Ferns




xylem and phloem
well-developed roots
rigid stems
Spores, NO seeds
Kingdom PLANTAE:
Division Gymnosperm






Naked-seed plants
Not protected by
fruit
Conifers
Pines, firs, cedars
No flowers
True vascular plants
Kingdom PLANTAE:
Division Angiosperm


Angiosperms, or flowering plants, are the
most familiar and diverse plants
There are two main types of angiosperms


Monocots include orchids, bamboos, palms,
lilies, grains, and other grasses
Dicots include shrubs, ornamental plants,
most trees, and many food crops
Kingdom PLANTAE:
Division Angiosperm

Monocots and dicots differ in seed leaf
number and in the structure of roots,
stems, leaves, and flowers
Kingdom FUNGI






Eukaryotic, heterotroph, mostly multicelled,
except yeast (single celled)
Multinucleate
Cell wall = chitin
Lack digestive system, release enzymes outside
body
Goes through digestion outside, takes in
nutrients through absorptive feeders
Decomposers
Kingdom FUNGI

A fungus usually consists of a mass of
threadlike hyphae

This forms a network called a mycelium
Kingdom FUNGI
Kingdom FUNGI

Most fungi cannot move

But they grow around and through their food
very rapidly
Kingdom FUNGI: Lichens

Lichens: associations of algae or cyanobacteria
with a network of fungal hyphae


The fungus receives food in exchange for housing,
water, and minerals
Lichens survive in hostile environments: tundra
frozen soil
Algal
cell
Fungal
hyphae
Kingdom ANIMALIA

eukaryotic, multicellular heterotrophs that
ingest their food


They lack cell walls
Most animals are diploid except for haploid
eggs and sperm
Kingdom ANIMALIA: Shape



Posterior / Anterior
Ventral / Dorsal
Radial Symmetry / Bilateral Symmetry
Kingdom ANIMALIA
Kingdom ANIMALIA:
Phylum Porifera (Sponges)

simplest animals, radially symmetrical,
Central axis
sessile
Kingdom ANIMALIA:
Phylum Cnidaria


simplest animals with tissues
Exist in two radially symmetrical forms


Polyps, such as hydra, corals, and sea
anemones
Medusas, the jellies
Kingdom ANIMALIA:
Phylum Cnidaria

nematocysts tentacles sting prey



The tentacles, controlled by nerves, then push
the food through the mouth into a
gastrovascular cavity
In the cavity, the food is digested and then
distributed
In cnidarians, only two cell layers are
produced during gastrulation
Kingdom ANIMALIA:
Phylum Cnidaria

Hydra’s gastrovascular cavity
Kingdom ANIMALIA:
Phylum Platyhelminthes (Flatworms)

Planarians – simple nervous system
consisting of a brain, sense organs, and
branching nerves

As in cnidarians,
the mouth of a
flatworm is the
only opening for
its gastrovascular
cavity
Kingdom ANIMALIA
Coelem: Body Cavity

Sponges, cnidarians, and flatworms lack a
body cavity
Coelem
Kingdom ANIMALIA: Coelem


Nearly all other animals have a body
cavity coelem.
fluid-filled space between the digestive
tract and the body wall

Cavity aids in movement, cushions organs,
and it may help in circulation
Kingdom ANIMALIA:
Phylum Nematodes (Roundworms)


Nematodes: body cavity not completely
lined by mesoderm
Like most animals, they possess a
complete digestive tract



This is a tube with a mouth and an anus
Some free-living
Others parasites
Kingdom ANIMALIA:
Phylum Mollusca

Large phylum



gastropods, such as snails and slugs
bivalves, such as clams and scallops
cephalopods, such as squids and octopuses
Kingdom ANIMALIA:
Phylum Mollusca


Have muscular foot andmantle (secretes shell –
except octopus/squid)
Mollusks have a true coelom and a circulatory
system, feed with a rasping radula
Kingdom ANIMALIA:
Phylum Annelid (Segmented Worms)

Segmentation: subdivision of some or
most of the body into a series of repeated
parts, or segments
Kingdom ANIMALIA:
Phylum Annelid (segmented worms)


Segmentation probably evolved as an adaptation
for movement
Segmented Worms, Arthropods, Vertebrates
Kingdom ANIMALIA:
Phylum Arthropod


Exoskeletons and jointed appendages
Most numerous and widespread




Crustaceans
Arachnids: 2 body parts (head, thorax)
Insects: 3 body parts (head, thorax,
abdomen)
Millipedes
Kingdom ANIMALIA:
Phylum Arthropod
Kingdom ANIMALIA:
Phylum Arthropod

Insect, most numerous: 3 body parts
Kingdom ANIMALIA:
Phylum Echinoderms

spiny skin, an
endoskeleton, a water
vascular system for
movement, radial
symmetry


sea stars and sea
urchins
The water vascular
system has suction-cuplike tube feet used for
respiration and
locomotion
Kingdom ANIMALIA:
Phylum Chordata

Organisms in this phylum are
segmented animals with four
distinctive features
Dorsal hollow nerve cord
 Stiff notochord
 Pharyngeal slits behind
the mouth
 Muscular post-anal tail
Most chordates are vertebrates
 Endoskeletons include skull
 Backbone composed of vertebrae


Kingdom ANIMALIA:
Phylum Chordata
Kingdom ANIMALIA:
Phylum Chordata
Class Fish

There are two classes of fish


Chondrichthyes, cartilaginous fishes such as
sharks : skates, stingrays, sharks
Osteichthyes, bony fishes such as tuna and
trout
Kingdom ANIMALIA:
Phylum Chordata
Class Fish

Bony fishes are more
diverse and have
 more mobile fins
 a buoyant swim
bladder
 Some have air-sacs
to absorb oxygen
from air in shallow
water (evolutionary
precursor to lungs)
Kingdom ANIMALIA:
Phylum Chordata
Class Amphibians


First land vertebrates
 Frogs, toads, salamanders
Amphibians first terrestrial
vertebrates
 Limbs allow them to move on
land
 However, amphibian larvae
must develop in water
 Breathe through lungs and
skin (moist)
Kingdom ANIMALIA:
Phylum Chordata
Class Reptiles


more terrestrial adaptations than amphibians
live on land due to




Thick skin / waterproof scales
Developed lungs
a shelled, amniotic egg
ectotherms

They warm their bodies by absorbing heat from the
environment
Kingdom ANIMALIA:
Phylum Chordata
Class Aves (Birds)

Like reptiles, class Aves has


scales
amniotic eggs
Kingdom ANIMALIA:
Phylum Chordata
Class Aves (Birds)

Other bird
characteristics include





wings
feathers
an endothermic
metabolism
hollow bones
a highly efficient
circulatory system
Kingdom ANIMALIA:
Phylum Chordata
Class Mammals



Class Mammalia descended from reptiles
Endothermic
Two unique mammalian characteristics


Hair, which insulates the body
Mammary glands, which produce milk that
nourishes their young
Kingdom ANIMALIA:
Phylum Chordata
Class Mammals


3 ways mammals give birth:
Monotremes: egg laying
Kingdom ANIMALIA:
Phylum Chordata
Class Mammals

Marsupials = short
gestation


The tiny offspring
complete development
attached to the mother’s
nipple, usually inside a
pouch
Example: kangaroos
Kingdom ANIMALIA:
Phylum Chordata
Class Mammals

Most mammals are
placentals


They have a relatively
long gestation
Complete embryonic
development occurs
within the mother