Lecture Exam #3 part 3 Flashcards
what do inverterbrates account for?
more than 95% of known animal species
animals that lack a back bone
inverterbrates
what are some distinctions of inverterbrates?
they are morphollogically diverse and occupy almost every habitat on earth
basal animals that lack tissues
sponges
what are animals in the phylum Porifera informally known as?
sponges
where do sponges live?
in marine waters or fresh water
what type of feeders are sponges?
filter feeders
feeding by capturing particles suspended in the water that passes through the body
filter feeder
how is water drawn in and out of a sponge?
through pores in a cavity called the spongocoel and out through an opening called the osculum
what do sponges lack?
true tissues and organs
flagellated collar cells, generate a water current through the sponge and ingest suspended food
choanocytes
what do sponges consist of?
a gelatinous noncellular mesohyl layer between 2 cells
found in the mesohyl and play roles in digestion and structure in sponges
amoebocytes
what are most sponges and what does that mean?
hermatphrodites, each individual function as both male and female
what are Cnidarians an ancient phylum of?
eumetazoans
what do all animals except sponges and a few other groups belong to?
the clade Eumetazoa
what type of animals are Eumetazoa ones?
animals with true tissues
what is the oldest clade in the Eumetazoans?
Phylum Cnidaria
what have Cnidarians diversified into?
both sessile and mobile forms
what do Cnidarians include?
jellies, corals and hyrdras
what do Cnidarians exhibit?
a relatively simple diploblastic, radial body plan
what does the basic body plan of a Cnidarian include?
a sac with a central digestive compartment, the gastrovascular cavity
how many openings does a Cnidarian have?
a single one that functions as the mouth and the anus
two variations on a Cnidarian body plan (SM)
1) sessile polyp
2) motile medusa
adheres to the substrate by the aboral end of its body
polyp
has a bell-shaped body with its mouth on the underside
medusa
what does Medusae not attached to?
the substrate but moves freely
what type of animals are cnidarians?
carnivores
how does cnidarians capture prey?
using their tentacles
what are Cnidarian’s tentacles armed with that function in defense and capture prey?
unique cells, cnidocytes
specialized organelles within cnidocytes that eject a stinging thread
neamtocysts
what 2 major clades did the Phylum Cnidaria diverge into early in its evolutionary history?
Medusozoa and Anthozoa
what does Meduzoans include?
all cnidarians that produce a medusa
types of medusozoans
1) scyphozoans (jellies)
2) cubozoans (box jellies)
3) hydrozoans
what do most hydrozoans alternate between?
polyp and medusa forms ge
where does the freshwater cnidarian, hydra exist only in?
polyp form
how do hydras reproduce?
asexually by budding
what stage in life is the medusa of most scyphozoans and cubozoans?
the predominant stage
what is an example of the medusa being the predominant stage?
coastal scyphozoans have a brief polyp stage whereas ocean species generally have a polyp stage
what do cubozoans often have?
highly toxic cnidocytes nal
what is an example of cubozoans having highly toxic cnidocytes?
the sting of the sea wasp off the coast of northern Australia can lead to respiratory failure, cardiac arrest and death within minutes
what does the clade Anthozoa include?
the corals and sea anemones
what does Anthozoans occur only as?
polyps
what do corals often form?
symbioses with algae
what does corals usually secrete?
a hard exoskeleton (external exoskeleton)
what does each generation of Anthozoans grow on?
the skeletal remains of the previous generation, forming “rocks” that provide habitat for other species
what is the clade Lophotochozoans identified by?
molecular data
what does the clade Lophotochozoans have the widest range of?
animal body forms
what does bilaterian animals have?
bilateral symmetry and triploblastic development
what type of digestive system do most bilaterian animals have?
a colemn and a digestive tract with two openings
what does the clade Bilateria include? (3) (LED)
1) lophotrochozoa
2) Ecdysozoa
3) Deuterostomia
why do some lophophore develop?
for feeding others pass through a trochophore larval stage and a few have neither
what does Lophotrochozoa include? (6) (FREBMA)
1) flatworms
2) rotifers
3) ectoprocts
4) brachiopods
5) molluscs
6) annelids
where do members of phylum Platyhelminthes live?
marine, freshwater and damp terrestrial habitats
although flatworms undergo triploblastic development what are they?
acoelomates
what type of digestive tract do flatworms have?
a gastrovascular cavity with one opening
in flatworms where does gas exchange take place?
across the surface and protonephridia (like a kidney) regulate the osmotic balance
what does flatworm’s dorsoventrally flattened shape maxamize?
surface area for gas exchange
two lineages that flatworms are divided into
1) catenulida or “chain worms” (reproduce asexually by budding)
2) Rhabditophora (more diverse and include both free-living and parasitic species)
what are the best known Rhabditophorans?
planarians
where do planarians live and what do they prey on?
in fresh water and prey on small animals
what do planarians have?
light-sensitive eyespots and centralized nerve nets
what type of nervous system do planarians have?
a more complex and centralized one than the nerve sets of cnidarians
what type of animals are planarians sexually?
hermaphrodites and can produce sexually or asexually through fission
where do parasitic rhabditophorans live?
in or on other animals
two important groups of parasitic rhabditophorans (TT)
1) trematodes
2) tapeworms
what do trematodes parasitize?
a wide range of hosts
what do most trematodes have?
complex life cycles alternating sexual and asexual stages
where do trematodes that paratisize humans spend part of their lives?
in snail hosts
what do trematodes that partisize humans produce?
surface proteins that mimic their host
what does the surface proteins that trematodes produce release?
molecules that manipulate the host’s immune system
what are tapeworms?
parasites of verterbrates
what do tapeworms lack?
a digestive system
what do tapeworms absorb?
nutrients from the host’s intestine
what does the scolex of a tapeworm contain?
suckers and hooks for attaching to the host
what are the proglottids in tapeworms?
units that contain sex organs and form a ribbon behind the scolex
what do fertilized eggs produced by sexual reproduction in tapeworms do?
leave the host’s body in feces
what type of animals are Rotifers in the phylum Rorifera?
tiny animals
where do rotifers live?
they inhabit fresh water, the ocean and damp soil
even though rotifers are smaller than many protists where are they truly?
multicellular and have specialized organ systems
what type of digestive system do rotifers have?
an alimentary canal
a digestive tube with a separate mouth and anus that lies within a fluid-filled pseducoelm
alimentary canal
how do rotiers reproduce?
by parthenogenesis
when females produce offspring from unfertilized egg
parthenogenesis
how are some species of rotifers unusual?
they lack males entirely
what do lophorates have?
a crown of ciliated tentacles around their mouth and a true coelom
what are the two phyla of lophorates? (EB)
1) ecroprocta
2) brachipoda
what are ectoprocts also called?
bryozoans
what type of animals are ectoprocts?
sessile (don’t move much) colonial animals
what do ectoprocts superficially resemble?
plants
what encases the colony in ectoprocts?
a hard exoskeleton
what are some species of ectoprocts?
reef builders
What do brachiopods superficially resemble?
clams and other hinge-shelled molluscs
how are brachiopods different than clams?
the two halves of the shell are dorsal and ventral rather than lateral as in clams
where do brachiopods live?
they are marine and most attach to the seafloor by a stalk
what does phylum Mollusca include? (3) (SOO)
1) snails and slugs
2) oysters and clams
3) octopuses and squids
where do most molluscs live?
most are marine though some inhabit fresh water and some snails and slugs are terrestrial
what type of animals are molluscs?
soft-bodied animals but most are protected by hard shell
3 main parts of molluscs body plan that all have (MVM)
1) muscular foot
2) visceral mass
3) mantle
what do many molluscs also have?
a water-filled mantle cavity
how do many molluscs feed?
using a rasplike radula
what are most molluscs sexually?
they have separate sexes with gonads located in the visceral mass but many snails are hermaphordites
what does the life cycle of many molluscs include?
a ciliated larval stage called a trochophore
4 major classes of molluscs (PGBC)
1) polyplacophora (chitons)
2) gastropoda (snails and slugs)
3) bivalvia (clams, oysters, and other bivalves)
4) cephalopoda (squids, octopuses, cuttlefish and chambered natiluses)
oval-shaped marine animals encased in an armore of eight dorsal plates
chitons
what do chitons use their foot like suction cup and radula for?
to grip rock and their radula to scrape algae of the rock surface
where do most gastropods live?
marine but many are freshwater and terrestrial species
how do gastropods move?
slowly by rippling motion of the foot or by cilia
what do most gastropods have?
a single, spiraled shell
what does the single,spiraled shell in gastropods function in?
protection from injury, dehydration and predation
what are most gastropods?
herbivores but some species use modified radula to feed on prey
what type of species are bivalves?
aquatic
what does bivalves include? (4) (COMS)
1) clams
2) oysters
3) mussels
4) scallops
what does bivavlves have?
a shell divided into 2 halves drawn together by abductor muscles
what does some bivalves have?
eyes and sensory tentacles alongthe edge of their mantle
what does the mantle cavity of a bivalve contain?
gills
what are gills used for in bivalves?
feeding as well as gas exchange
what are most species of bivavles?
sedentary but some have limited mobility
what type of species are cephalopods
carnivores with beak-like jaws surrounded by tentacles of their modified foot
how are cephalopods able to immobilize their prey?
with a poison present in their saliva
how do most octopuses (cephalopods) search for prey?
by creeping along the sea floor
what allows squid (cephalopods) to swim quickly?
they use their siphon to fire a jet of water
what is the one group of shelled cephalopods that survive today?
nautiluses
characteristics of cephalopods (3) (CWC)
1) closed circulatory system
2) well-developed sense organs
3) complex brain
what are shelled cephalopods called?
ammonites
when did ammonites go extinct?
at the end of the Cretaceous 65.5 million years ago
which animal group had the largest number of recent extinctions?
molluscs
most threatened molluscs (2) (FT)
1) freshwater bivalves (including pearl mussels)
2) terrestrial gastropods (including Pacific island land snails)
what are the most threatened molluscs threatened by?
1) habitat loss
2) pollution
3) non-native species
coelomates with bodies composed of a series of fused rings
annelids
3 clades of annelids (POH) (old way)
1) Polychaeta (polychaetes)
2) Oligochaeta (oligochaetes)
3) hirundinea (leeches)
most recent 2 major clades of annelids (ES)
1) Errantia
2) sedentaria
what are most membrs of the clade Errantia?
mobile, marine organisms
what do many erratians have?
a pair of paddle-like or ridge-like structures called parapodia (besides feet) on each body segment
what does each parapodium have?
numerous chaetae bristles made of chitin
what is not unique to the Erratian clade?
parapodia
what do sedentarians tend to be less of than erratians?
mobile
what do some species of sedentarians do?
burrow into the substrate while others live in protective tubes
what do tube-dwelling sedentatians often have?
elaborate gills or tentacles used for filter feeding
what does the sedentarian clade also contain?
leeches and earthworms
where do most species of leeches live?
in fresh water, some are marine and terrestrial
what do leeches include?
predators of invertebrates and parasites that suck blood
what do leeches secrete?
a chemical called hirudin
what does hirudin do?
prevents blood from coagulating
how do earthworms eat?
through soil, extracting nutrients as the soil moves through the alimentary canal
what are earthworms sexually?
hermaphrodites but cross-fertilize
how do some earthworms reproduce?
asexually by fragmentation sozoans
what is the most species-rich animal group?
Ecdysozoans
what are ecdysozoans covered by?
a tough coat called a cuticle
the process when the cuticle is shed or molted
ecdysis
two largest phylum of Ecdysozoans (NA)
1) nematodes
2) arthropods
where are nematodes or roundworms found? (4) (MSMB)
1) most aquatic habitats
2) in the soil
3) in moist tissues of plants
4) body fluids and tissues of animals
what type of digestive system do nematodes have?
an alimentary canal
what do nematodes lack?
a circulatory system
what are body wall muscles in nemataodes and what does their contraction produce?
longitudinal and they produce a thrashing motion
what is a model organism in research with nematodes?
Caenorhabdtitis elegans
what are some species of nematodes?
important parasites of plants and animals
what type of nematodes could be acquired by humans from uncooked pork?
Trichinella spiralis
how many species of animals are arthropods?
two out of every three known species
where are members of the phylum Arthropoda found in?
nearly all habitats of the biosphere
what does the arthropod body plan consist of? (3) (SHJ)
1) segmented body
2) hard exoskeleton
3) jointed appendages
what does the arthropod body plan date to?
the Cambrian Explosion
what did early arthropods show?
little variation from segment to segment
what is arthropod evolution characterized by? (2) (DI)
1) decrease in number of segments
2) increase in appendage specialization
what are changes to arthropods caused by?
changes in Hox gene sequence or regulation
what functions are the appendages of some living arthropods modified for? (5)(WFSRD)
1) walking
2) feeding
3) sensory reception
4) reproduction
5) defense
what are modified appendages of arhtopods?
jointed and come in pairs
what is the body of a arthropod completely covered by?
the cuticle
what is the cuticle of an arthropod made of?
layers of protein and polysaccharide chitin
when an arthropod grows what happens to its exoskeleton?
it molts
what sensory organs do arthropods have? (3) (EOA)
1) eyes
2) olfactory receptors
3) antennae (functions in touch and smell)
what type of circulatory system do arthropods have?
open
how does the circulatory system operate in arthropods?
hemolymph is circulated into the spaces surrounding the tissues and organs
what do a variety of organs specialize in arthropods evolved for?
gas exchange
what suggests that arthropods consist of 3 major lineages that diverged early in the phylum’s evolution?
morphologicals and molecular evidence
3 lineages of arthropods (CMP)
1) chelicerates
2) myriapods
3) pancrustaceans
what are most modern chelicerates and what does that include?
arachnids, includes spiders, scorpions, ticks and mites
how many pairs of appendages do arachnids have?
6
what do the 6 pair of appendages that arrachnids have consist of? (3) (CPF)
1) the chelicerae
2) the pedipalps
3) four pairs of walking legs
where does gas exchange occur in spiders?
in respiratory organs called book lungs
what do many spiders produce?
silk, a liquid protein from specialized abdominal glands
what does the clade myriapods include?
millipedes and centipedes
what are all living myriapods?
terrestrial
what parts do myriapods have?
1) a pair of antennae
2) 3 pairs of appendages modified as mouthparts
what do millipedes eat?
decaying leaves and plant matter
what do millipedes have?
many legs with two pairs per trunk segment
what type of animals are centipedes?
carnivores
what do centipedes have?
one pair of legs per trunk segment
what do poison claws on the foremost trunk segment of centipedes do?
paralyze prey and aid in defense
what does recent evidence indicate about terrestrial insects?
that they are more closely related to crustaceans than myriapods
what are some lineages of crustaceans more closely related to?
insects than other crustaceans
what does together insects and crustaceans form?
the clade pancrustacea
where do crustaceans live?
in marine and freshwater environments
what do many crustaceans have?
highly specialized appendages
what do small crustaceans exchanges gases through?
the cuticle
what do larger crustaceans use to exchange gasses?
gills
do most crustaceans have separate male and female?
yes, not a lot of hermaphradites
what do isopods include?
terrestrial, freshwater and marine species
what is a well known group of terrestrial isopods?
pill bugs
what are decapods?
relatively large crustaceans
what does decapods include?
lobsters, crabs, crayfish and shrimp
what does planktonic crustaceans include?
many species of copepods
what are among the most numerous of all animals?
copepods
what are copepods rivaled in abundance by?
shrimplike krill
what are a group of mostly sessile crustaceans?
barnacles
what do barnacles have?
a cuticle
what is the cuticle of barnacles hardened into?
a calcium carbonate shell
what is an enormous clade including insects and their relatives?
Hexapoda
where do insects live?
in almost every terrestrial habitat and in fresh water
what does the internal anatomy of an insect include?
several complex organ systems
what did the diversification of insects follow? (3) (EAE)
1) the evolution of flight
2) adaption to feeding on gymnosperms
3) the expansion of angiosperms
when did insect and plant diversity decline?
during the Cretaceous extinction but has been increasing in the 65 million years since
what is the one key to great success of insects?
flight
what advantages does an animal that can fly have? (3) (EFD)
1) can escape predators
2) find food
3) disperse to new habitats much faster than organism that can only crawl
what are insect wings?
an extension of the cuticle
what do many insect undergo during their development?
metamorphasis
the young called nymphs, resemble adults but are similar and go through a series of molts until they reach full size
incomplete metamorphosis )
have larval stages known by such names as maggot, grub or caterpillar
complete metamorphsis
what is true of the larval stage of complete metamorphosis
it looks entirely different from the adult stage
metamorphasis stages of a butterfly (5) (LPLEA)
1) larva (caterpillar)
2) pupa
3) later stage pupa
4) emerging adult
5) adult (butterfly)
what do most insect have sexually?
separate male and females that reproduce sexually (not many hermaphradites)
how do individuals of insects find and recognize members of their own species by? (3) (BSO)
1) bright colors
2) sound
3) odors
what are some insects in terms of disease?
some are beneficial as pollinators while other are harmful as carriers of disease or pests of crops
what are insects classified into?
more than 30 orders
what do chordates (phylum chordata) include?
verterbrates
what clade do Echniderms and chordates constitute?
Deuterostomia
developmental characteristics that deuterostomes share (2) (RF)
1) radial cleavage
2) formation of the anus from the blastophore
what are deuterostomes defined primarily by?
DNA similarities
what is an example of a free living species of nematode?
caenorhabditis elegans
what are some examples of parasitic species of nematodes? (5) (TADRM)
1) trichinella (forms cysts in skeletal muscle)
2) ascaris (found in digestive system of farm animals)
3) dog heartworm
4) river blindness)
5) many plant diseases
advantages to having an exoskeleton (3) (TPP)
1) thin and flexible
2) provides support against gravity
3 protection from dehydration
disadvantages of having an exoskeleton
doesn’t grow with organism
