understandings: the binomial system of names for species is universal among biologists and has been...
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UNDERSTANDINGS:•The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses.•When species are discovered they are given scientific names using the binomial system.•Taxonomists classify species using a hierarchy of taxa.•All organisms are classified into three domains.•The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species.•In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species.•Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species.•Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.
TOPIC 5.3 CLASSIFICATION OF BIODIVERSITYESSENTIAL IDEA: SPECIES ARE NAMED AND CLASSIFIED USING AN INTERNATIONALLY AGREED SYSTEM
Applications and skills:•Application: Classification of one plant and one animal species from domain to species level.•Application: Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta.•Application: Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata.•Application: Recognition of features of birds, mammals, amphibians, reptiles and fish.•Skill: Construction of dichotomous keys for use in identifying specimens.
TOPIC 5.3 CLASSIFICATION OF BIODIVERSITYESSENTIAL IDEA: SPECIES ARE NAMED AND CLASSIFIED USING AN INTERNATIONALLY AGREED SYSTEM
CLASSIFICATION OF INVERTEBRATE ANIMALSTopic 5.3
PLANTAE“PROTISTS” ANIMALIAFUNGI
Ap
ico
mp
lexa
ns
Cili
ates
Kin
eto
pla
stid
s
Eu
gle
nid
s
Dip
lom
on
ads
Ph
aeo
ph
yta
(bro
wn
alg
ae)
Oo
myc
ota
(wat
er m
old
s)
Rh
od
op
hyt
a(r
ed a
lgae
)
Ch
loro
ph
yta
(gre
en a
lgae
)
Bry
op
hyt
a(l
iver
wo
rts,
mo
sses
)
Pte
rid
op
hyt
a(f
ern
s)
Zyg
om
yco
ta
Am
oeb
ozo
ans
Asc
om
yco
ta
Bas
idio
myc
ota
Po
rife
ra(s
po
ng
es)
Cn
idar
ia(a
nem
on
es, j
elly
fish
)
Pro
tost
om
es(w
orm
s, a
rth
rop
od
s, m
ollu
sks)
Deu
tero
sto
mes
(sea
urc
hin
s, s
ea s
tars
, ver
teb
rate
s)
Dia
tom
s
Din
ofl
agel
late
s
An
gio
sper
ms
(flo
wer
ing
pla
nts
)
Gym
no
sper
ms
EUKARYOTIC TREE OF LIFE
WHAT ARE THE KEY FEATURES OF ANIMALS?
Animals possess all of the following characteristics Multicellularity Their cells lack a cell wall They obtain energy by consuming other
organisms Most reproduce sexually They are motile at some point in the life cycle They are able to respond rapidly to external
stimuli
AN EVOLUTIONARY TREE OF SOME MAJOR ANIMAL PHYLA
LACK OF TISSUES SEPARATES SPONGES FROM ALL OTHER ANIMALS
Tissues are groups of similar cells that carry out a specific function (e.g., muscle)
Sponges are the only modern-day animals that lack tissues Individual cells in sponges may be specialized, but they act independently and are not organized into true tissues
Sponges and all remaining tissue-containing phyla arose from an ancient common ancestor without tissues
PORIFERA (SPONGES) Sponges have a simple body plan found in most marine and aquatic
environments occur in a variety of sizes and shapes may reproduce asexually by budding or
sexually through fusion of sperm and eggs
CNIDARIANS
Sea jellies, sea anemones, corals, and hydrozoans belong to the phylum Cnidaria
These animals are mostly marine and are all carnivorous predators
The cells of cnidarians are arranged into distinct tissues, including a contractile muscle-like tissue and an organized nerve net
PLATYHELMINTHES (FLATWORMS) may be parasitic or free living in aquatic,
marine, and moist terrestrial habitats are bilaterally symmetrical can reproduce both sexually and asexually;
most are hermaphroditic, having both male and female sexual organs
head (attachment site)adult tapeworm
7
5
6
1
2
3
4
8
6 inches
A larvaltapewormis liberated bydigestion and attaches tothe human’sintestine
The tapeworm matures in a humanintestine, producing a series ofreproductive segments; each segmentcontains both male and female sex organs
Eggs are shed fromthe posterior end of theworm and are passedwith human feces
A pig eats foodcontaminated byinfected feces
Larvae hatchin the pig’s intestine
The larvae migrate throughblood vessels to pig muscle
The larvae formcysts in pig muscle
A human eatspoorly cookedpork withlive cysts
THE LIFE CYCLE OF THE HUMAN PORK TAPEWORM
Fig. 23-10
PLATYHELMINTHES (FLATWORMS)
Another group of parasitic flatworms is the flukes
Flukes have complex life cycles that include an intermediate host, such as a snail
Blood flukes cause schistosomiasis, which causes symptoms such as diarrhea, anemia, and possible brain damage
As many as 200 million people worldwide may be infected with flukes
ANNELIDA (SEGMENTED WORMS) The annelid body is divided into a series of
repeating units (segmentation) The segments contain identical copies of nerves,
excretory structures, and muscles that allows for complex movement
Annelids have a fluid-filled coelom The coelom functions as a hydrostatic skeleton,
where pressurized fluid provides a framework against which muscles can act
One way digestive tract
MOLLUSCA The three classes of mollusks are:
Gastropods Bivalves Cephalopods
MOLLUSCA - GASTROPODS are one-footed crawlers
The snails and slugs are collectively known as gastropods They have a muscular foot for locomotion They may possess a shell, but not all gastropods are
shelled They feed using a radula, a flexible ribbon studded
with spines that scrape algae from rocks or grasp larger plants or prey
Most use their skin and gills for respiration, but terrestrial mollusks have a simple lung
MOLLUSCA - BIVALVES are filter feeders
Bivalves include scallops, oysters, mussels, and clams They live in fresh water and marine habitats They possess two shells that can be clamped shut by a
strong muscle They are filter feeders and use gills for both feeding
and respiration Most have a muscular foot used for burrowing or for
attaching to rocks
MOLLUSCA - CEPHALOPODS are marine predators
Cephalopods have tentacles with chemosensory abilities and suction disks
These animals are able to move rapidly by forcefully expelling water from the mantle cavity
They possess closed circulatory systems
ARTHROPODS
Arthropods are the most diverse and abundant animals The phylum Arthropoda includes insects,
arachnids, myriopods, and crustaceans Arthropods have appendages and an
exoskeleton (external skeleton) The exoskeleton is secreted by the epidermis (the
outer layer of skin) It is composed primarily of protein and chitin (a
polysaccharide)
THE EXOSKELETON MUST BE MOLTED
Fig. 23-18
THE DIVERSITY OF ARACHNIDS
Fig. 23-22
THE DIVERSITY OF MYRIAPODS
Fig. 23-23
THE DIVERSITY OF CRUSTACEANS
Fig. 23-24
ECHINODERMS calcium carbonate
skeleton includes sand dollars, sea
urchins, sea stars, sea cucumbers, and sea lilies Echinoderm larvae exhibit
bilateral symmetry; adults show radial symmetry
They exhibit deuterostome development
They possess an endoskeleton (internal skeleton) that sends projections through the skin
PHYLUM CHORDATA
The phylum Chordata includes two invertebrate groups (the sea squirts and the lancelets) plus the vertebrates
CLASSIFICATION OF VERTEBRATE ANIMALS
Applications and skills:•Application: Classification of one plant and one animal species from domain to species level.•Application: Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta.•Application: Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata.•Application: Recognition of features of birds, mammals, amphibians, reptiles and fish.•Skill: Construction of dichotomous keys for use in identifying specimens.
TOPIC 5.3 CLASSIFICATION OF BIODIVERSITYESSENTIAL IDEA: SPECIES ARE NAMED AND CLASSIFIED USING AN INTERNATIONALLY AGREED SYSTEM
Vertebrates
TetrapodsC
ho
nd
rich
thye
s(s
har
ks,
rays
)
Act
inis
tia
(co
elac
anth
s)
Act
ino
pte
ryg
ii(r
ay-f
inn
ed f
ish
)
Pet
rom
yzo
nti
form
es(l
amp
reys
)
Dip
no
i(l
un
gfi
shes
)
Am
ph
ibia
(fro
gs,
sala
man
der
s)
Rep
tili
a(t
urt
les,
sn
akes
cro
cod
iles
,b
ird
s)
Mam
mal
ia(m
amm
als)
Dorsal nerve cord, notochord,pharyngeal gill slits, post-anal tail
Vertebral column
Jaws
Lungs
Skull
Lobed fins
Limbs
Amniotic egg
Hair, milk
AN EVOLUTIONARY TREE OF THE VERTEBRATES
VERTEBRATE ADAPTATIONS Several adaptations have allowed vertebrates to
successfully invade most habitats presence of an internal skeleton that can grow and repair
itself allowed for greater size and mobility, enabling these animals to invade most habitats
Jaws evolved to allow these animals to exploit a much wider range of food sources than jawless animals that preceded them
The development of paired appendages (fins, legs, wings) helped to stabilize movement
The increased size and complexity of the brain and sensory structures allowed these animals to perceive their environment in detail and to respond in a variety of ways
WHAT ARE THE MAJOR GROUPS OF VERTEBRATES?
Today, vertebrates include the following groups: Lampreys Cartilaginous fishes Ray-finned fishes Lungfishes Amphibians Reptiles (and birds) Mammals
LAMPREYS Some
lampreys parasitize fish
jawless rounded
sucker that surrounds the mouth
spinal cord is protected by cartilaginous segments
live in both fresh and salt waters
CARTILAGINOUS FISHES Cartilaginous fishes are
marine predators They are of the class
Chondrichthyes, and include sharks, skates, and rays
Most are marine They possess jaws and
a cartilaginous skeleton Their body is protected
by a leathery skin embedded with tiny scales
BONY FISHES
the most diverse vertebrates Bony fish are found in nearly every watery
habitat, both freshwater and marine This group includes:
Ray-finned fishes, such as the angler fish, the moray eel, and the sea horse
Lobe-finned fishes, which include the lungfish and the coelacanth
THE DIVERSITY OF RAY-FINNED FISHES most diverse and abundant group of vertebrates
Fins which are formed by webs of skin supported by bony spines
bony skeleton skin is covered with interlocking scales two-chambered heart gills are for respiration Most have a swim bladder
LOBED-FINNED FISHES
fleshy fins that contain rod-shaped bones surrounded by a thick layer of muscle Some of these modified fleshy fins could be used to
drag the fish from a drying puddle to a deeper pool This gave rise to the first vertebrates to invade land—the
amphibians Some of the lineages of lobefins left descendents
that survive today and are the tetrapods (amphibians, reptiles, and mammals)
frogs, toads, salamanders, and caecilians
Amphibians begin life adapted to an aquatic environment (e.g., tadpoles have gills) They later mature into semi-terrestrial adults with lungs
three-chambered heart adults respire through lungs and
moist skin Most have four limbs Most are confined to moist habitats use of external fertilization requires
water eggs, protected only by a jelly-like
coating, are vulnerable to water loss
Amphibians:
REPTILES
class Reptilia and are adapted for life on land These animals evolved from an
amphibian ancestor about 250 million years ago Reptiles include lizards, snakes,
alligators, crocodiles, turtles, and birds They respire exclusively through lungs tough scaly skin that protects the body
and resists water loss internal fertilization with shelled
amniotic egg three- or four-chambered hearts efficient lungs and do not use their skin
as a respiratory organ
BIRDS
distinctive group of reptiles They appear in the fossil
record 150 million years ago
They are distinguished from other reptiles by feathers, which are highly specialized reptilian body scales
Modern birds retain scales on their legs, which is evidence of the ancestry they share with the rest of the reptiles The earliest known bird is
called Archaeopteryx
ARCHEOPTERYX, THE EARLIEST-KNOWN BIRD
MAMMALS
Mammals appeared in the fossil record about 250 million years ago They did not diversify and dominate terrestrial habitats until the
dinosaurs became extinct (65 million years ago) Mammals are warm-blooded with high metabolic rates a four-chambered heart hair that protects and insulates legs designed for running rather than crawling provide milk to their offspring sweat, scent, and sebaceous (oil-producing) glands, which
are not found in other vertebrates Mammals are subdivided into three groups
Monotremes Marsupials Placental mammals
are egg-laying mammals This group includes only three species, the platypus and
two species of spiny anteater (echidnas), and are found only in Australia and New Guinea Platypuses forage for food in the water and eat small vertebrate
and invertebrate animals Echidnas are terrestrial and eat insects and worms they dig out of
the ground Monotremes lay leathery eggs rather than giving birth to
live young The newly hatched young are nourished from milk secreted by
the mother
MONOTREMES
MARSUPIA Species include the opossums, koalas, kangaroos,
wallabies, wombats, and the Tasmania devil In marsupials, embryos begin development in the
uterus of the female Young are born at a very immature stage and must crawl
to and grasp a nipple to complete development Post-birth development, in most, is completed in a
protective pouch
PLACENTAL MAMMALS
inhabit land, air, and sea This highly diverse class
includes bats, moles, impalas, whales, seals, monkeys, and cheetahs The uterus contains a
placenta that functions in gas, nutrient, and waste exchange between circulatory systems of mother and embryo
In placental mammals, young are retained in the uterus for their entire embryonic development