Test 3- animals

what characteristics do sponges share with choanoflagellates

* Both are benthic (live at bottom of aquatic environments) • Both are sessile as adults (adults live permanently attached to a substrate rather than moving freely) • Both feed using cells with nearly identical morphology • Beating flagella of choanoflagellates and specialized cells in sponges called choanocytes trap organic debris • Feeding and digestion occurs at the cellular level

As animals diversified, a wide array of even more specialized sensory abilities evolved allowing for the detection of:

* Magnetic fields * Electric Fields * Barometric Pressure

protection of sponges

*Spicules • Toxins/warning coloration • Toxic secondary metabolites • Some sea slugs co-opt sponge defenses (toxins,spicules) • Regenerative ability • Camouflage

Importance of protostomes:

- Major direct source of food for humans - Provide ecosystem services - Some damage crops - Some produce materials such as silk and pearls - Cause or transmit human diseases and are parasites - Include two of the most important model organisms (fruit fly and roundworm)

How do fossils provide evidence for evolution of animals?

- Provide direct evidence of what ancient animals looked like, when they existed, and where they lived - However, the fossil record does not represent all animals equally • Animals that were most likely to fossilize were abundant, had hard body parts and lived in areas where sedimentation was occurring • Soft bodied groups do not fossilize well

coral feeding

-Capture zooplankton - could contain mutualistic zooxanthellae

Purpose of exoskeleton

. Protection from predators • Provides an effective structure for muscle attachment • During molting, the animal's soft body is exposed and vulnerable

Phylogenetic analyses consistently support two monophyletic clades within the protostomes:

1) Lophotrozoans 2) Ecdysozoans

In insects, the presence or absence of a larval stage Defines two distinct types of metamorphosis:

1) hemimetabolous 2) Holometabolous

The feeding tactics observed in animals can be broken into four general types:

1) suspension feeders (filter feeders) 2) Deposit feeders 3) fluid feeders 4) mass feeders

Biologists recognize four major lineages of arthropods:

1. Chelicerates 2. Myriapods 3. Crustaceans 4. Insects

Two morphological traits occur in some, but not all, members of lophotrochozoans:

1. Feeding structure called a lophophore, which is found in three phyla 2. A type of larva called a trochophore, which is common to many of the phyla

Where does evidence for evolution come from for animals?

1. Fossils 2. Comparative morphology, development and genomics

protostomes living on land involves adaptations for:

1. Gas exchange 2. Conserving water 3. Supporting bodies under their own weight

Recent DNA sequence data support two major subgroups within the protostomes:

1. Lophotrochozoa include mollusks, annelids, flatworms and rotifers 2. Ecdysozoa include the nematodes, arthropods, water-bears and velvet worms

Three main groups of annelids:

1. Polychaeta 2. Oligochaeta 3. Hirudinea

Arthropods are defined by three key features (bauplan):

1. They have segmented bodies organized into prominent regions, or tagmata (singular: tagma) 2. Their exoskeleton is composed primarily of chitin, strengthened by calcium carbonate (CaCO3) in crustaceans 3. They have jointed appendages, which enable the rigid body to move

The flatworms are a large and diverse phylum consisting of four major lineages:

1. Turbellaria 2. Cestoda 3. Trematoda 4. Monogenea

diploplasts

2 germ layers

triploplasts

3 germ layers

biologists currently recognize how many major lineages of animals?

30-35 phyla

origins of sponges date back to

700 mya

how many species of sponges have been described

8000

Cambrian explosion

A burst of evolutionary origins when most of the major body plans of animals appeared in a relatively brief time in geologic history; recorded in the fossil record about 545 to 525 million years ago.

Medusa

A free-swimming cnidarian with a bell-shaped body and tentacles

internal fertilization

A male typically inserts a sperm- transfer organ into the female's body

Fragmentation

A means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals.

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

monophyletic

ALL descendants came from one common ancestor

If Ctenophores and Cnidarians lack true mesodermal muscle, how do these shape changes take place?

All animals share homologous genes for contractile proteins • Actin and myosin

parthenogenesis

All female reproduction from unfertilized eggs

blastocoelomate

An adjective defining any animal that has a fluid-filled body cavity, or blastocoel.

Asymetrical

An animal with no lines of symmetry (sponges)

Heterotroph

An organism that cannot make its own food.

Deuterostomes

Animals in which the blastopore becomes the anus during early embryonic development

Detritivores

Animals that eat dead organic matter

Carnivores

Animals that feed on other animals

Herbivores

Animals that feed on plants or algae

animal appendages

Are homologous

Tardigrada and Onychophora are of special interest to biologists due to their close relationship to ___________.

Arthropods

budding

Asexual reproduction in which buds fall and develop into a new sponge

scolex of tapeworm

Attaches the worm to the host's intestines (head)

What is a protostome?

Biologists traditionally distinguish the protostomes from deuterostomes using developmental characteristics: 1. Embryonic development of the mouth before the anus during gastrulation 2. Inability of isolated early embryonic cells to develop into a complete embryo 3. The formation of a coelom by the splitting of blocks of mesodermal cells

rotifers are ______________ with digestive, excretory, and reproductive systems

Blastocoelomates

Cnidocytes

Cells that house the stingers in cnidarians.

morphological features

Characteristics of organisms based on physical or anatomical traits

Dramatic radiation of mollusks into several lineages:

Chitons (mollusks with dorsal shells made of plates) • Bivalves (clams and mussels) • Gastropods (slugs and snails) • Cephalopods (squid and octopuses)

Vertebrates are a monophyletic lineage within the

Chordata

phylum of corals

Cnidaria

sea anemone

Cnidaria

what phylum are box jellies?

Cnidarian

Multicellular

Consisting of many cells

The gene _________ was originally implicates in limb development of flies. It is also expressed in developing limbs of annelids, anthropods, echinoderms, and vertebrates!

DII

detritus

Dead organic matter

sessile

Describes an organism that remains attached to a surface for its entire life and does not move

Limbs

Develop as outpockets of the body wall and can take a variety of forms

In most sexually reproducing organisms, __________ __________ life cycles

Diploid dominant

Polychaetes

Diverse worms that live in a wide variety of marine habitats

segmentation

Division of body or a part of body into a series of similar structures

Cephalization

Evolution of a distinct head where structures for feeding, sensing the environment, and processing information are concentrated.

convergent evolution

Evolution toward similar characteristics in unrelated species

Characteristic bauplan of Mollusks

Foot Visceral Mass Mantle

Epitheliomuscular cells

Form most of epidermis and cause muscular contraction

Spongocoel

Found in sponges, it is the central cavity into which water is drawn to filter nutrients

Amoebocytes

Found in sponges, these cells are mobile and perform numerous functions, including reproduction, transport of food particles to nonfeeding cells, and secretion of material that forms the spicules

Parasites

Harvest nutrients from parts of their hosts

molting

Involves shedding of a hard exoskeleton • Once the animal molts, fluid causes the body to expand—then a new, larger cuticle or exoskeleton forms • Ecdysozoans undergo a succession of molts as they grow

sexual reproduction

Involving meiosis and the fusion of gametes is the most common mode of reproduction

Examples of Eumetazoans

Jellyfish, Corals, Hydrozoans, Box Jellies and Sea Anemones

Predator

Kill and consume all or most of their prey using an array of mouthparts and hunting strategies

cerebral ganglion (brain)

Large mass of neurons that is responsible for sending and receiving information to and from the body

Animals from different ___________ with similar __________ often pursue the same food sources and feeding strategies

Lineages, niches

Molecular data confirms the placement of flatworms within the

Lophotrochozoa

external fertilization

Male releases sperm into the environment, female releases eggs ( common in aquatic species)

Mollusks (Phylum Mollusca)

Mollusks are a highly diverse monophyletic group of lophotrochozoan

Thus, there is a trade-off between protection and mobility in mollusks

Mollusks with thick shells are constrained to aquatic habitats, where buoyant forces help support the load • The largest mollusks have highly reduced shells or none at all • Terrestrial mollusks have thin shells or none at all

asexual reproduction is ___________ __________ than sexual reproduction but sexual reproduction leads to greater _______ ________

More efficient/ genetic diversity

Where are sea anemones found?

Most inhabit tropical reefs, but some found in colder waters

Cnidarians have no?

No head, no special body systems for circulation, gas exchange or excretion

Lophotrochozoa

One of two distinct clades within the protostomes. It includes annelids, mollusks, flatworms, and rotifers.

epidermis

Outer layer of skin

Water-bears and Velvet worms

Phyla Tardigrada and Onychophoran

what phylum are jellyfish?

Phylum Cnidaria

What phylum are flatworms in?

Phylum Platyhelminthes

phylum of sponges

Phylum Porifera

what is the phylum of sponges

Phylum Porifera

predator-prey relationship

Predators exert selection pressure on their prey for characteristics that enable them to escape capture, on predators to capture prey(evolutionary arms race)

what type of feeders are sea anemonies

Predators or filter feeders, some form symbiotic associations with zooxanthellae

rotifers are found where

Predominantly freshwater, some marine

Some protostome phyla have little diversity, such as the phylum_________, which contains only 16 named species

Priapula

endoskeleton

Rigid structures inside the body, such as bones in vertebrates and spicules in sponges

magnetic field sensory

Some animals can detect magnetic fields and use them as a navigation aid (sea turtles)

Electric fields sensory

Some aquatic predators can detect electrical activity in the muscles of passing prey (sharks)

Barometric pressure sensory

Some birds can avoid storms by sensing changes in air pressure

examples of suspension feeders

Sponges, clams, barnacles, and baleen whales

deposit feeders

Take in organic matter (living or dead) found in or on sediments, food consist of bacteria, archaea, protists, and fungi, and detritus

Fission Reproduction

The parent separated into two or more offspring of equal size

Chordata

The phylum of the animal kingdom that includes vertebrates.

polyp

The sessile, tubular form of a cnidarian with a mouth and tentacles at one end and a basal disk at the other

extracellular matrix (ECM)

The substance in which animal cells are embedded, consisting of protein and polysaccharides synthesized and secreted by cells.

holometabolous metamorphosis

There is a distinct larval stage • Larvae and adults often live in different habitats and feed on different foods • In holometabolous metamorphosis, larvae stop feeding and moving and secrete a protective case, becoming a pupa • During pupation, the pupa's body is completely remodeled into a new, adult form

actin and myosin

These proteins are found in the contractile cells of Ctenophores and Cnidarians but they are derived from endoderm and/or ectoderm

what type of feeders are protostomes

They can be detritivores, herbivores, or carnivores

____________ are endoparasitic (Digenea) or ectoparasitic (Monogenea) flatworms that parasitize vertebrates, arthropods, annelids, and mollusks

Trematodes

Oligochaeta ecosystems include:

Tunnels that are important in aerating soil • Feces contribute large amounts of organic matter

____________ form a paraphyletic group of ______________flatworms

Turbellarians free-living

Phylum Nematoda are ___________worms with a ________, a tube-within-a-tube body plan, no appendages, and anelastic cuticle that is molted during growth.

Unsegmented Blastocoleom

Herbivores usually consume plant tissue _______

Without killing the entire organism

Embryos in oviparous and ovoviviparous species are nourished by

Yolk within the egg

colloblasts

a cell that is found on the tentacles of a ctenophore and that secretes a sticky substance

deep homology

a condition that occurs when the growth and development of traits in different lineages result from underlying genetic mechanisms that are inherited from a common ancestor

Insects have three tagmata— ________ pairs of walking legs extend from the sides of the thorax • Most species have one or two pairs of ________ on the back of the thorax

a head, thorax, and abdomen • Three pairs of walking legs extend from the sides of the thorax • Most species have one or two pairs of wings on the back of the thorax

foot (mollusks)

a large muscle located at base of the animal, used in movement

Bilaterians that have no coelom, such as the flatworms(phylum Platyhelminthes), are called

acoelomates

flatworms are ___________ and have no ________ or _______ systems

acoelomates, respiratory, circulatory

Where are sponges found?

all are aquatic, most species are marine

Ctenophores have no ____________, no sessile stage

alternation of generations

Protosome

an animal whose mouth is formed from the blastopore ("first- mouth)

Omnivores

animals that eat both plants and animals

The Ecdysozoans

animals that molt

triploblasts

animals whose embryos 3 germ layers: 1. ectoderm 2.endoderm 3. mesoderm

Diploblasts

animals whose embryos have two germ layers: 1. the ectoderm ("outside- skin") 2. the endoderm ("inside- skin")

Eumetazoans

animals with true tissues (phylum Cnidaria)

some of the same developmental tool-kit genes are involved in segmentation in both phyla of

annelids and arthropods: convergent evolution homology at genetic level

The cephalothorax lacks __________, but usually has eyes

antennae

Crustaceans have two pair of _______ and _________ eyes

antennae / compund

crustaceans live primarily in __________ environments, where they play important ecological roles

aquatic

the distribution of flatworms in nature is restricted to _________ or_________environment

aquatic/moist

The tardigrades, or "water bears,"

are microscopic animals that live in diverse marine, freshwater, and terrestrial environments, such as in the film of water that covers plants in moist habitats

centipede

are predators and have poison fangs

• The onychophorans, or velvet worms are _______________________.

are small, caterpillar-like organisms that live in moist leaf litter and prey on small invertebrates

Cestodes (tapeworms)

are strictly endoparasitic flatworms that parasitize vertebrates, absorbing nutrients by diffusion across their body wall

Monogeneans

are tiny ectoparasites that attack specific tissues of particular species, usually the skin or gills of fishes

Ecdysozoans

arthropods and nematodes • Molt by shedding their exoskeletons and expanding their bodies

Phylum Arthropoda

arthropods are the most important phylum within the Ecdysozoa • Appear in the fossil record over 520 million years ago • Most abundant animals observed in both aquatic and terrestrial environments • Over a million living species have been described

Some species of rotifers obligately ___________.

asexual

Many cnidarians have two distinct life stages

asexual polyp and sexual medusa

Polyps of jellyfish are sedentary and reproduce ___________

asexually

sponges are the most _________ group of animals

basal

Biologists hypothesize that the evolution of the head and nervous system are tightly linked to the evolution of ____________________

bilateral symmetry

nearly all species of ctenophores are ______________ (glow)

bioluminescent

Bilaterians whose coelom is only partially lined with mesoderm, such as roundworms (phylum Nematoda) and rotifers (phylum Rotifera), are known as

blastocoelomates

Turbellarians have a _______ digestive tract

blind

hemocoel

blood cavity where fluids bathe the organs directly in an open circulatory system in mollusks (but not in cephalopods)

The _________ (a Digenean trematode) is responsible for schistosomiasis—a serious public health issue in many tropical and subtropical nations, infecting more than 200 million people worldwide• They feed by gulping host tissues and fluids, often causing blood in the host's urine or stool, kidney failure, and other problems

blood fluke

Bauplan

body plan

Benthic

bottom dwelling

benthic

bottom dwelling

Central Nervous System (CNS)

brain and spinal cord

Crustacean appendages are usually _________, but some have lost this characteristic, becoming secondarily unbranched.

branched

Assexual reproduction in ctenophores

budding fission

asexual reproduction in sponges

budding, fragmentation,

Unlike lophotrochozoans that grow continuously and incrementally, ectozoans grow intermittently ______________.

by molting

In many species of mollusks, the mantle secretes a shell made of ___________ ____________

calcium carbonate

suspension feeders (filter feeders)

capture food by filtering out particles suspended in water or air

archaeocytes

cells that digest food intracellularly captured by choanocytes, they also function in waste elimination and secrete spicules and/or spongin

The nervous systems of animals are diverse, ranging from a nerve net in diploblasts to a more complex _____________in triploblasts

central nervous system (CNS)

he common ancestor of annelids had numerous, bristle-like extensions called _______ (a synapomorphy)

chaetae

metamorphosis

change of form

chelicerates are named for a pair of claw like appendages called __________, located near the mouth

chelicerae

pedipalps are found on

chelicerates

thorax

chest, pleural cavity

mandibles and maxillae

chewing mouthparts of crustaceans

egg production in sponges

choanocytes or amoebocytes transform into oocytes

sperm production in sponges

choanocytes transform into spermatogonia (in choanocyte chambers or after migrating into the mesohyle)

sponges share characteristics with

choanoflagellates

Both larval and adult Ctenophores swim using ________, but in most species, adults also have ________ tissue that can change the body's shape

cilia contractile

ctenophores have eight rows of _________ or combs controlled by an ______ ________ __________

ciliary plates/ apical sense organ

Oligochaeta

class of earthworms

Ganglia

clusters of nerve cell bodies

Most annelids have a _________, a fully developed ________ with a mouth and an anus, and a segmented body

coelom digestive tract

Bilaterians whose coelom is completely lined with mesoderm are known as true

coelomates

Ctenophores have No cnidocytes, instead they have adhesive structures known as _____________

colloblasts

Siphonophores (Hydrozoans) are ___________ with both medusa and polyps

colonial

Choanoflagellates sometimes form _________ (groups of attached individuals)

colonies

common name of phylum Ctenophora

comb jellies

paraphyletic

consists of an ancestral species and some, but not all, of its descendants

monophyletic clade

consists of the ancestor species and all its descendants

Pax genes

control eye development

HOX genes set the identity of segments from head to tail

control when and where other genes are expressed

what has most have 4-6 pairs of mouthparts derived from jointed appendages

crustaceans

what type of feeders are oligochaeta

deposit feeders in soils

Epitheliomuscular cells

derived from ectoderm and endoderm

In Nematoda gas exchange occurs by _________ across the body wall, and nutrients move by ___________ from the gut to other parts of the body.

diffusion

Cestodes lack ______,_________, and _________ systems

digestive, circulatory, and respiratory

In bivalves (clams and oysters),the foot is modified as a ______________

digging appendage

Ctenophores are __________ with endoderm and ectoderm separated by a cellular ______________

diploblastic/ mesenchyme

Bilaterally symmetric organisms tend to move through their environment in a

directional manner: • It is advantageous to have many neurons concentrated at that end • Nerve tracts carry information from the head down the length of body

sensory organs

ears, eyes, nose, skin (touch), tongue

Protostomes occupy a huge number of niches and play very important

ecological roles

Monogenea Trematodes

ectoparasitic

Oviparous

egg laying

mesenchyme

embryonic connective tissue

• Some sponges have true epithelial tissue but no

embryonic tissue layers (i.e. Ectoderm, endoderm or mesoderm)

Digenean Trematodes

endoparasitic

what two tissue layers do cnidarians have

epidermis and gastrodermis

sponges do have _________ tissue

epithelial

As a group, protostomes live in virtually

every aquatic and terrestrial habitat on earth

maxillipeds or claws

feeding appendages on the thoracic segments of crustaceans

polyps in siphonophores are specialized for what?

feeding, defense, and asexual reproduction

Depending on the species, the chelicerae are used in

feeding, defense, copulation, movement, or sensory reception

Choanocytes

flagellated collar cells, generate a water current through the sponge and ingest suspended food

Pinacocytes

flattened contractile cells enables sponges to undergo shape change

hydrostatic skeleton

flexible skeleton supported by fluid pressure

Sponges provide ____ and ___ for many other organisms

food and habitat

outer tube

forms nervous system and skin

basal

foundation

The head of an insect has ________ pairs of mouthpart structures, one pair of slender ________ that are used to touch and smell, and a pair of __________ eyes

four antennae compound

Larvae of some species are common in ______________ environments

freshwater aquatic

Most turbellarian species are where

freshwater or marine

Reefs consist of millions of living polyps connected to each other through a common _________________

gastrovascular cavity

mesoglia/mesenchyme (Cnidaria)

gelatinous layer between epidermis and gastrodermis (non-living but contains ameboid cells)

mesohyl

gelatinous matrix within a sponge

endoderm

generates the digestive tract

Some terrestrial arthropods and mollusks have _________or other respiratory structures located inside the body • This minimizes water loss in terrestrial environments

gills

mesoderm

gives rise to the tissues in between

Unlike most flatworms blood flukes are __________

gonochoristic

radial symmetry

have at least two planes of symmetry (cnidarians, ctenophores, and some sponges)

Ctenophores have both male and female functions making most of them

hermaphroditic

In bivalves, the protective shell is

hinged and closes

Chelicerate tagmata are not _________ to those in other arthropods, even though they are functionally similar

homologous

The ecological importance of protostomes extends to

human health

Snails and chitons have a large,muscular foot at the base of the body that works as a type of __________

hydrostatic skeleton

what is the common ancestor to all animals

hypothesized to be a single-celled protist /choanoflagellates

Mesoderm and Coelom Formation

in between forms muscles and organs

gastrodermis

in cnidarians, the layer of cells surrounding the digestive tract

As the animal genetic tool kit evolved, the potential for morphological diversity ____________

increased

In clams, two siphons extend into the water column above, controlling _________________ over the gills

incurrent and excurrent water flow

Mass feeders

ingest chunks of food (humans, lions, elephants)

In some terrestrial snails, the mantle forms an

internal lung

Ctenophores digestion

intra and extracellular

digestion in cnidarians is both _______ and ________

intra and extracellular

body symmetry

is a key morphological feature of an animal's Bauplan

coelom

is an enclosed, fluid-filled body cavity between the tubes

Pax6

is required for normal eye development in all animals with bilateral symmetry

inner tube

is the gut with a mouth on one end and an anus at the other

Visceral Mass (Mollusca)

is the region in all mollusks where organs and surrounding fluids are located, separate from the muscular foot

Hirudinea

leeches • Many are ectoparasites that attach themselves to fish, humans, or other hosts and suck blood and other body fluids • Nonparasitic leech species are predators or scavengers

The hemocoel is different from a true coelom because it is not __________ and has a different developmental origin

lined in mesoderm

Ectoparasites

live outside their hosts and usually have limbs or mouthparts that allow them to grasp the host's body (ticks, lice)

endoparasite

lives inside the host (tapeworm, flukes)

Pedipalps (Chelicerae)

located just behind the chelicerae, which may be used to manipulate food, transfer sperm, or carry out other functions

nerve net

loosely organized network of nerve cells that together allow cnidarians to detect stimuli

A compound eye contains

many lenses, each associated with a light-sensing, columnar structure

99% of Eumetazoans are

marine

Osmoconformers

marine animals which, in contrast to osmoregulators, maintain the osmolarity of their body fluids such that it is always equal to the surrounding seawater.

cells of sponges communicate ______ and ________

mechanically and chemically

corals have no _______ stage in life cycle

medusa

Muscles of ctenophores develop from ___.

mesenchyme cells

Phylum Mollusca

mollusks

The coelom is highly reduced in most _________, functioning mostly in ________________

mollusks reproduction and excretion of wastes

Lophotrochozoans

mollusks, annelids, flatworms, and rotifers • Do NOT molt

over 85,000 ____________ have been described, and about 1.2 million ___________species, of which about a million are insects • Scientists estimate that the actual number of arthropod species may be over 10 million

mollusks, arthropod (protostomes)

The lophotrochozoans are a ____________ group

monophyletic

segmentation allows for

morphological specialization

Through the process of natural selection, a niche is the evolutionary result of a species _________, ________, __________ adaptations to its surroundings.

morphological, physiological, and behavioral

millipede

mostly feed on detritus

The larvae of sponges are:

motile

protosomes

mouth first

Maxillae

mouthparts on head of crustaceans

sponges do not have _______, _____, or _________ systems

muscle, nerve, or organ

____________operating on variation in gene expression within populations, has led to the enormous diversification of arthropod body segments and appendages

natural selection

a ________ net is present in ctenophores

nerve

Sponges lack both __________ cells and __________.

nerve and symmetry

Radially symmetrical cnidarians and ctenophores have nerve cells that are organized into a

nerve net

the nervous system of cnidarians is a

nerve net

Acoelomate

no body cavity

Sponges have ____ symmetry.

no distinct

Mesohyle

non-living middle body layer that contains living amoeboid cells called archeocytes

• Fossils indicate that protostome lineages originated in the ________ and subsequently invaded __________ • Unlike plants, however, protostomes seem to have made this transition ____________ over evolutionary history

ocean, land multiple times

blind digestive tract

only one opening through which food goes in and indigestible waste comes out

osculum

opening at the top of the sponge where water leaves

Statocyst

organ of balance, found in jellyfish

Like sponges and Cnidarians they Ctenophores are ___________

osmoconformers

• Water flows into the sponge through ________ and out through the _____________

ostia, osculum

Even organisms without eyes, such as sponges, have Pax genes; this finding suggests that Pax proteins originally controlled

other processes

Mantle (Mollusca)

outgrowth of the body wall that covers the visceral mass, forming an enclosure called the mantle cavity

ectoparasitic

outside host

Gonads

ovaries and testes, sponges have none

Chaetae extend from lobe-like appendages called _________

parapodia

Oligochaeta have no _______ but do have chaetae

parapodia

Polychaetes that are highly mobile often have large ___________ and_________

parapodia chaetae

Mouth of turbellarians is near middle of body's ventral surface, at the end of a tube-like structure called the _______which can be extended to catch prey or collect other food

pharynx

Siphonophores (Hydrozoan)

phylum cnidaria

The larval stage of a cnidarian is known as a

planula- has a flattened, ciliated body

carapace

plate like section of exoskeleton that covers and protects head and thorax on some species of crustaceans

what is most responsible for the endangerment of coral reefs

pollution and rising temperatures

many jelly fish have life cycles that includes both ________ and ________

polyp and medusa

Two strikingly different body plans are found in Eumetazoans:

polyp and the medusa

hermaphrodite

produce both eggs and sperm (sponges

ectoderm

produces the covering of the animal

viviparous

producing living young (not eggs)

Ovoviviparous

producing living young from eggs that hatch within the body

Choanoflagellates

protists that are the closest living relatives of animals

Turbellarians prey on

protists, small animals, or scavenge dead animals

Ctenophores are ___________ symmetric

radially

cnidarians are ______ symmetrical

radially

in mollusks at the anterior end of the visceral mass, the mouth has a feeding structure called a ________, which functions like a rasp or file (not present in bivalves)

radula

Cambrian explosion

rapid diversification of most major animal groups

Sponge cells can _________ after being dissociated

reaggregate

Niche

refers to the way in which an organism fits into an ecological community or ecosystem

Osmoregulation

regulation of solute concentrations and water balance by a cell or organism

excretory system

removes waste from the body

Nematoda lack specialized__________and _____________ systems.

respiratory and circulatory

Ctenophores have no __________, ___________, _________ systems

respiratory, circulatory or excretory

Exoskeletons

rigid structures on the outside of the body, such as the external armor of arthropods

Phylum Rotifera

rotifers

Phylum Nematoda

roundworms

Invertebrates (a paraphyletic group)

segmentation conspicuous in annelids and arthropods

Phylum Annelida

segmented worms

Gonochoristic

separate male and female sexes

Hox genes

series of genes that controls the organs and tissues that develop in various parts of an embryo, are expressed in the same order as their physical location

sponge adults are what kind of feeders

sessile suspension feeders

Medusa of jellyfish are free-swimming and produce_________

sexually

Sponges reproduce

sexually (external fertilization) and asexually

Synapomorphy

shared derived characteristics

Synapomorphy

shared derived trait

myriapods have relatively _______ bodies consisting of a head region and a long ________ with segments bearing one (centipedes) or two pairs of legs (millipedes)

simple trunk

Ocelli

simple light receptors, found in jellyfish

bilateral symmetry

single plane of symmetry

In bivalves and cephalopods, the mantle is lined with muscle and forms tubes (water can flow in and out) called

siphons

sedentary

sitting

Ctenophores are predators on

small zooplankton

Spicules

small, spike shaped particles of calcium carbonate or silicon dioxide that make up the skeleton of some sponges

Where are ctenophores found?

solely marine, surface to deep ocean

sea anemones may be ________ or _________

solitary/ colonial

Spongocoel (atrium)

spacious cavity in the sponge

Sponges have skeletal elements called

spicules, spongin composed of calcium carbonate, silicon dioxide, and/or collagen

If the environment dries, openings to respiratory passages in protostomes (_________) can be_______

spiracles, closed

Lophotrochozoans have a ________ cleavage

spiral

multicellularity appears to have originated in a

sponge-like animal

___________ are the earliest animals to appear in the fossil record are the earliest animals to appear in the fossil record

sponges

what animal is the most basal lineage

sponges

cnidocytes and nematocysts

stinging cells containing barbs found on cnidarian tentacles used to capture food

In cephalopods, the mantle cavity fills with water and then mantle muscles contract, forcing a __________________________. The force of the expelled water provides a form of locomotion called jet __________________.

stream of water out of a single siphon Propulsion

phyla

subsets below the kingdom level

fluid feeders

suck or mop up liquids like nectar, plant sap, blood, or fruit juice (hummingbird, vampire bat)

flatworms flattened bodies provide a large ___________for gas exchange This allows nutrients and gases to _______ efficiently to all of the cells inside the animal with minimal expenditure in complex respiratory structures

surface area diffuse

Some protostomes (flatworms, roundworms) have ahigh _______________ ratio • This increases the efficiency of gas exchange across their body surfaces in their moist environments

surface-area-to-volume

bivalves acquire food by

suspension feeding

medusa in siphonophores are specialized for what?

swimming and sexual reproduction

In cephalopods, the foot is modified to form ____________ for crawling and grasping

tentacles

Insects dominate ____________ environments

terrestrial

The most prominent lineages of chelicerates are _____________

terrestrial (spiders, scorpions, ticks, mites, and daddy longlegs), some are marine (horseshoe crabs and sea spiders)

copulation

the act of mating

Chelicerate bodies consist of two tagmata:

the cephalothorax (prosoma) and the abdomen opisthosoma)

Higher oxygen levels allow for

the evolution of big, mobile animals due to the efficiency of aerobic respiration

embryogenesis

the formation and development of an embryo

he segmented body of most crustaceans is divided into three tagmata:

the head, thorax, and abdomen,

hemimetabolous metamorphosis

the juvenile form is called a nymph and looks like a miniature adult

Pinacoderm

the outer layer of the sponge body made up of pinacocytes, functions to keep small molecules drom diffusing in and out of the sponge

Visceral Mass (Mollusca)

the region containing most of the main internal organs and external gill

genetic toolkit

the regulatory genes that govern developmental processes that have been highly conserved throughout evolution

Insect eggs have a __________ that keeps in moisture

thick membrane

Snail and slug eggs have a __________that retains water

thick shell

Pharynx

throat

Copepods

tiny, shrimp-like crustaceans that are often the most free-floating animals in estuarine waters

Why do animals move?

to obtain food, find mates, escape from predators, and disperse into new habitats

molt

to shed the exoskeleton and grow a new one

Ctenophores are receptive to

touch, light, vibration, temperature, certain chemicals

homologous traits

traits are similar because they were inherited from a common ancestor

analogous trait

traits are similar not due to shared inheritance, but because they evolved independently (by convergent evolution)

Crustaceans have ___________ tagmata, branched appendages, and two pairs of __________

two or three antennae

Some mollusk species have a shell with one, two, or eight parts, called _______; others have no shell at all

valves

A segmented backbone is one of the defining characteristics of

vertebrates

Insects have a ________to minimize water loss to the atmosphere

waxy layer

Insects were the first animals on Earth to evolve ________ Molecular genetic research provides evidence that wings arose from __________ projections on the branched legs of a wingless ancestor

wings gill-like

Rotifers are one of the main ___________ groups.

zooplankton

Ctenophores can have an effect on the population of _______, ________, and ________

zooplankton, larval fish, and invertebrates

You can be confident that an animal belongs to the Lophotrochozoa if you observe any of the following:

• A lophophore • A trochophore larvae • Spiral cleavage However, not all lophotrochozoans possess all three of these characteristics

Animals form a monophyletic clade of eukaryotes with key traits

• All are multicellular • Unlike plants they have no cell walls, but animal cells do have an extensive extracellular matrix (ECM) • All are heterotrophs (but see Elysia) • All are mobile at some point in their life cycle • Except for sponges, all have nerve and muscle cells

How do comparative morphology, development, and genomics provide evidence for evolution of animals?

• Biologists must distinguish between homologous and analogous traits • Homologous traits are similar because they were inherited from a common ancestor • Analogous traits are similar not due to shared inheritance, but because they evolved independently (by convergent evolution)

Choanocytes function

• Circulate water • Capture small food particles • Capture incoming sperm for fertilization

Traditionally, two phyla of animals are recognized as diploblasts:

• Ctenophora (comb jellies) • Cnidaria (jellyfish, corals, sea pens, hydra, and anemones)

What Is the Adaptive Significance of Metamorphosis?

• Holometabolous metamorphosis is 10 times more common than hemimetabolous metamorphosis • Biologists hypothesize that this is because of feeding efficiency • If adults and juveniles feed on different materials they do not compete with each other for resources

epithelial tissue

• It consists of tightly joined cells that covers interior and exterior surface of animal

sexual reproduction in ctenophores

• Most hermaphrodites; may self-fertilize • Gonads within the gastrovascular canals • Eggs and sperm spawned via pores (external fertilization in the open sea) • Adults generally die after spawning

Because they lack any organs, sponges depend on water flow for:

• Obtaining food • Gas exchange • Waste removal • Dissemination and collection of sperm

compare Tardigrada and Onychophora to arthropods

• They are similar to arthropods in having a segmented body and segmented limbs • Unlike arthropods, their cuticle is not hardened as an exoskeleton, and their limbs are not jointed

Roundworms play an important ecological role

• They feed on a wide variety of materials including bacteria, archaea, fungi, plant roots, small protists, and detritus • In most species, the mouthparts are structured in away that increases the efficiency of feeding on a particular type of organism or material • Most roundworms are free-living, others parasitize animals, including humans