Module 4: Practice Problems

What body system is found in both the members of Phylum Onychophora and the arthropod Class Hexapoda?

A tracheal system with spiracles that open to the outside of the body.

99% of all Osteichthyes belong in the Subclass ________.

Actinopterygii

All of the echinoderms have ______ symmetry as adults, except perhaps the Class ________, which seems to show somewhat ______ symmetry due to having 3 ambulacral rows on the ________ surface and 2 on the ________ surface.

All of the echinoderms have pentaradial symmetry as adults, except perhaps the Class Holothuroidea, which seems to show somewhat bilateral symmetry due to having 3 ambulacral rows on the ventral surface and 2 on the dorsal surface.

Class Merostomata

Appendages on abdomen fused to create opercula for book gills

Why are reptile lungs proportionately so much larger than amphibian lungs?

Because reptiles breathe solely via their lungs, while amphibians breathe both via small lungs and across their moist skin.

Why do crocodilians have a 4-chambered heart when amphibians and other reptiles have a 3- chambered heart?

Because they spend so much time underwater and not breathing, they need a very efficient circulatory system in order to properly oxygenate their bodies. 4 chambers keep the oxygen-rich and oxygen-poor blood separated in 2 separate ventricles, instead of allowing them to mix as in a 3-chambered heart.

Two classes are found in the Superclass Agnatha. Name the classes and explain how they feed if they don't have jaws

Class Myxini (hagfishes) use 2 toothed plates to feed; feed on dead animals Class Petromyzontida (lampreys) use a buccal funnel lined with teeth and a rasping tongue to create holes in the skin of their host in order to feed off blood/body fluids

To which class do the organisms at right belong, and what is their common name?

Class Sabellidae; Christmas tree worms

What is the difference between a detritivore and a scavenger?

Detritivores eat organic particles that they find, from any organisms. Scavengers eat the soft tissues of dead/decaying animals.

Order Isopoda

Dorso-ventrally flattened; important benthic nutrient cyclers

What hormone is primarily responsible for the cycle of molting in crustaceans?

Ecdysone

What does evisceration mean when discussing the Class Holothuroidea? What gets eviscerated? When/why does it occur?

Evisceration refers to the expulsion of internal organs to the exterior of the body. The sea cucumbers eviscerate their respiratory trees, gonads, and cuverian tubules (if they have them), and can regenerate all of these as needed. This is used as a deterrent to predators, as the eviscerated items are often sticky (and sometimes toxic), and occupy the predator while the cucumber crawls away.

True or False: All arthropods possess a head with 2 pair of antennae, one pair of mandibles, and 2 pairs of maxillae.

False: All crustaceans possess a head with 2 pair of antennae, one pair of mandibles, and 2 pairs of maxillae.

True or False: All members of the Class Asteroidea have 5 or more arms

False: All sea star members of the Class Asteroidea have 5 or more arms, but sea daisies do not have any arms.

True or False: Class Bivalvia contains only sessile animals

False: Class Bivalvia contains many sessile animals, except for burrowing clams and swimming scallops.

True or False: Copepods, isopods, and amphipods all belong to the same class of crustaceans

False: Copepods belong to the Class Hexanauplia, while isopods, and amphipods belong to Class Malacostraca. They all belong to the same Subphylum Crustacea.

True or False: Members of the Class Ophiuroidea use their tube feet for locomotion, much as the Asteroids do.

False: Members of the Class Ophiuroidea use their very agile arms almost like legs for locomotion, unlike the Asteroids do.

True or False: Members of the Onychophora are strictly marine

False: Members of the Onychophora are strictly terrestrial in moist environments

True or False: Monoplacophorans are extinct

False: Monoplacophorans were thought to be extinct, until they were discovered in the deep ocean in 1952.

True or False: All echinoderms have a complete gut

False: Most echinoderms have a complete gut, except for the Class Ophiuroidea.

True or False: All echinoderms have a water vascular system filled with sea water

False: Most echinoderms have a water vascular system filled with sea water, except for the Class Holothuroidea, which fills its system with coelomic fluid.

True or False: All gastropods possess a shell

False: Most gastropods possess a shell, except for the slugs and nudibranchs.

True or False: Most molluscs have a closed circulatory system

False: Most molluscs have an open circulatory system, except cephalopods.

True or False: Octopuses have 8 tentacles

False: Octopuses have 8 arms

True or False: Ontogenetic torsion and coiling are the same thing

False: Ontogenetic torsion and coiling are not the same thing. Ontogenetic torsion is the 180° twisting of the body that brings the anus anterior above the head. Coiling is the elongating and spiraling of the visceral mass, causing the shell to become sinistral or dextal, as opposed to planospiral

True or False: All ecdyozoans are coelomates

False: Some ecdyozoans are coelomates, while others are acoelomates (rare) or pseudocoelomates

True or False: Loriciferans are able to enter a state of cryptobiosis to withstand harsh environmental conditions.

False: Tardigrades are able to enter a state of cryptobiosis to withstand harsh environmental conditions.

True or False: The Hirundinids are all freshwater

False: The Hirudinids are mostly freshwater, but there are some that are parasitic on sea turtles.

True or False: The Echinoids feed using a structure called Aristotle's Lantern.

False: The Holothuroideans feed using a structure called Aristotle's Lantern.

True or False: The Phylum Mollusca is the largest phylum in terms of number of species

False: The Phylum Mollusca is the 2nd largest phylum in terms of number of species; Arthropoda is 1st.

True or False: The protochordates are composed of the Class Enteropneusta and Class Pterobranchia.

False: The Subphylum Hemichordata is composed of the Class Enteropneusta and Class Pterobranchia.

True or False: The echinoderms do not have well-developed respiratory organs, except for the Class Ophiuroidea , which has respiratory trees.

False: The echinoderms do not have well-developed respiratory organs, except for the Class Holothuroidea, which has respiratory trees.

True or False: The maxially glands in crustaceans are used for digestion

False: The maxially glands in crustaceans are used for osmoregulation.

True or False: The polychaeta's use their parapodia just for locomotion

False: The polychaeta's use their parapodia for locomotion and respiration

True or False: The priapulids exhibit metamerism

False: The priapulids exhibit superficial segmentation (they are not segmented inside).

Elongation of the echinoderm larva leads to the chordate larva

Garstang's theory

How does the nerve cord of chordates differ from those of most invertebrates?

It is hollow and dorsal to the digestive tract. In most inverts, the nerve cord is solid and lies ventral to the digestive tract.

A common ancestor to echinoderms, hemichordates, and chordates is likely

Jollie's theory

What two sensory systems make the Chondrichthyes such amazing predators?

Lateral line and Ampullae of Lorenzini

Order Thoracica

Live life upside-down, extending cirri for feeding

Members of the Urochordate retain the chordate synapomorphies of _________ and ______ in the adult form, while the Cephalochordates retain _______ in the adult form.

Members of the Urochordate retain the chordate synapomorphies of pharyngeal slits and endostyle in the adult form, while the Cephalochordates retain all 5 chordate synapomorphies in the adult form.

Nematomorpha have a _______ larval stage that requires an ___________.

Nematomorpha have a parasitic larval stage that requires an arthropod.

Class Branchiopoda

No abdominal appendages, but contain phyllopodia on thorax to use for respiration

Class Pycnogonida

No circulatory or excretory system; diffuse gases and waste through body surface (usually of legs)

What allows echinoderms to have amazing powers of regeneration?

Pleuripotent stem cells

Order Decapoda

Possess a carapace and 5 pairs of walking legs

Subclass Copepoda

Single median eye

Ontogenetic torsion caused the anus to be located above the head in the Class Gastropoda. This can cause biofouling of the gills. What ways have gastropods evolved to reduce this fouling?

Some of them have undergone detorsion, which moves the anus back to a posterior position (such as in the nudibranchs). Others have undergone coiling of the shell, which caused an outward elongation of the visceral mass and subsequent loss of the kidney and gills on the side where the anus is located. Others use a unidirectional flow of water through the mantle to allow wastes to wash out of the mantle cavity instead of washing over the gills.

What is the difference between segments and tagmata?

Tagamata are body portions formed by the fusion of segments to perform specialized functions.

What does a crustacean's carapace typically do? What are 2 modifications we discussed for those Malacostracans not possessing a carapace?

The carapace protects the head and gills. Neither the Isopods nor Amphipods possess a carapace, but they have other structures to protect their gills. The Isopods use specialized abdominal appendages called lamellar pleopods, while Amphipods have coxae, which are extensions off the dorsal thoracic segments that partially protect the gills.

The dorsal nerve cord becomes the __________ in vertebrates.

The dorsal nerve cord becomes the central nervous system in vertebrates.

The first jawed fish were the ____________. Their name means ________.

The first jawed fish were the Placoderms. Their name means plate-skinned.

Describe how the Family Siboglonidae obtain nutrition

These are the vent worms or beard worms. While they can absorb some nutrients through their plumes at the anterior end, these worms do not have a digestive tract. They rely on the symbiotic chemosynthetic bacteria housed in their trophosome for the majority of their nutrition.

The Order Euphausacea has only about 90 species, but is incredibly important in the marine food web. What is the common name of these animals, and who relies on them?

They are krill, which are eaten by balleen whales, whale sharks, and other animals.

Why do amphibians need to live near water and in moist environments? Give 2 reasons.

They need to lay their eggs in water (since the eggs aren't shelled and will quickly desiccate otherwise), and they need to keep their skin moist in order to exchange gases across the skin.

Why do birds have such a strong, large breast bone (sternum)?

They require special musculature to power their wings, and this bone gives those muscles suitable attachment.

Some crustaceans have appendages that are attached to their gills underneath the carapace. What advantage does this give those animals?

This can help the gills to move back and forth underneath the carapace, which allows for greater water/gill interaction in an area where there is not a lot of flow-through of the water.

Why was it important for the rib cage to extend ventrally in tetrapods?

To protect the internal organs in animals whose bellies might drag on the ground.

True or False: Adult nematomorphs are aquatic.

True

True or False: All Malacostracans have both thoracic and abdominal appendages.

True

True or False: All arthropods show some amount of tagmatization.

True

True or False: All ecdyozoans molt their cuticle.

True

True or False: All echinoderms have tube feet.

True

True or False: Members of the Class Echinoidea lack arms.

True

True or False: Members of the Phylum Loricifera are the only animals that can live in entirely anoxic environments.

True

True or False: Nearly every member of the Phylum Annelida exhibits metamerism

True

True or False: Sea cucumbers often have other animals living in their anus.

True

True or False: The Class Cephalopoda contains mostly predators.

True

True or False: The Phylum Arthropoda shows more diversity and a greater number of species than any other animal phylum.

True

True or False: The annelids typically use a hydrostatic skeleton to assist with locomotion.

True

True or False: The notochord of chordates is filled with fluid, and provides support via muscles attaching to it.

True

True or False: There are more nematodes on earth than any other type of metazoan.

True

Two groups in the Phylum Annelida have no metamerism. These are the ________ and the ________.

Two groups in the Phylum Annelida have no metamerism. These are the Echiurids and the Sipunculids.

What subphyla make up the protochordates?

Urochordata and Cephalochordata

Order the following parts of the Class Asteroidea water vascular system. Use "1" to denote where water enters the system, and count up from there. ___ Ampullae ___ Ring Canal ___ Tube Feet ___ Madreporite ___ Radial Canal ___ Stone Canal

_5__ Ampullae _3__ Ring Canal _6__ Tube Feet _1__ Madreporite _4__ Radial Canal _2__ Stone Canal

For each of the following, pick the correct answer. Vertebrates typically...: a. Are larger/smaller than invertebrates b. Are motile/sessile c. Have higher/lower metabolic demands than invertebrates d. Have reduced/increased cephalization from invertebrates

a. Are larger than invertebrates b. Are motile c. Have higher metabolic demands than invertebrates d. Have increased cephalization from invertebrates

Which of the following are traits of all Deuterostomes? Choose all that apply. a. Cell differentiation through induction more than cytoplasmic specification b. Formation of the coelom through schizocoely c. Formation of the coelom through enterocoely d. Formation of the anus from the blastopore

a. Cell differentiation through induction more than cytoplasmic specification c. Formation of the coelom through enterocoely d. Formation of the anus from the blastopore

The Class Clitellata members all have a clitellum. Which of the following is it used for (choose all that apply)? a. Creates a cocoon for embryo formation b. Assists in feeding c. Assists in locomotion d. Assists in reproduction

a. Creates a cocoon for embryo formation d. Assists in reproduction

Which of the following are traits of the Class Chondrichthyes? Choose all that apply. a. Lack an operculum b. Have "scales" that are actually modified teeth c. Have a bony skeleton d. Reproduce only through internal fertilization

a. Lack an operculum b. Have "scales" that are actually modified teeth d. Reproduce only through internal fertilization

Which of the following are nematodes? Choose all that apply. a. Pin worms b. Heartworms c. Filarial worms (cause elephantiasis) d. Penis worms

a. Pin worms b. Heartworms c. Filarial worms (cause elephantiasis)

Which of the following are strictly mammal synapomorphies? Choose all that apply. a. Produce milk b. Sweat, fat, and scent glands c. Hair made of keratin d. 3 middle ear bones that improve the sense of hearing e. Endothermy

a. Produce milk b. Sweat, fat, and scent glands c. Hair made of keratin d. 3 middle ear bones that improve the sense of hearing

List 4 developments in arthropods that have made them the most diverse and abundant animal phylum.

a. They have a highly protective exoskeleton that allows for protection and better attachment sites for muscles b. They are segmented with flexible joints and have highly specialized, jointed legs c. They have highly developed sensory systems, along with complex behaviors d. The fact that larva and adults generally feed on different organisms and live in different areas decreases intraspecific competition for resources

What makes the Phylum Hemichordata "half chordates"? a. They have pharyngeal gill slits and a buccal diverticulum that looks like a proto-notochord b. They have a post-anal tail with musculature c. They have a dorsal hollow nerve cord d. They have an endostyle

a. They have pharyngeal gill slits and a buccal diverticulum that looks like a proto-notochord

Which one of the follow do cephalopods use to change their color/patterns for camouflage and other behaviors? a. chromatophores b. ampullae of lorenzini c. chaetae d. radula

a. chromatophores

Where are the tube feet of the Class Crinoidea? a. On the cirri b. In the food grooves of the arms c. Along the pinnules d. On the aboral side of the calyx

b. In the food grooves of the arms

Which of the following animals uses scalids to assist in locomotion? a. Loricifera b. Kinorhyncha c. Tardigrada d. Priapulida

b. Kinorhyncha

Ancestors of the arthropods underwent "arthropodization". Which of the following are examples of this modification? Choose all that apply. a. The cuticle became softer b. The coelom regressed to a hemocoel c. Motile cilia were lost d. Segmentation with flexible joints allowed for greater locomotion.

b. The coelom regressed to a hemocoel c. Motile cilia were lost d. Segmentation with flexible joints allowed for greater locomotion.

Why is there some confusion as to whether arrow worms are protostomes or deuterostomes? Choose all that apply. a. They have pharyngeal gill slits and a buccal diverticulum that looks like a proto-notochord b. Their anus forms before their mouth and their coelom develops through enterocoely c. They have a dorsal hollow nerve cord and a post-anal tail d. They have molecular similarities to protostomes

b. Their anus forms before their mouth and their coelom develops through enterocoely d. They have molecular similarities to protostomes

Which of the following classes uses captacula to burrow? a. Class Gastropoda b. Class Cephalopoda c. Class Scaphopoda d. Class Bivalvia

c. Class Scaphopoda

The most populous member of the zooplankton belongs to the: a. Class Branchiopoda b. Order Decapoda c. Subclass Copepoda d. Order Amphipoda

c. Subclass Copepoda

What group of animals gave rise to the tetrapods? a. Class Chondrichthyes b. Subclass Holocephali c. Subclass Sarcopterygii d. Class Amphibia

c. Subclass Sarcopterygii

The newest chordate synapomorphy determined is the endostyle/thyroid gland. How are these two items similar? a. They both produce mucus b. They're both involved in feeding c. They both produce proteins that are bound with iodine d. They are both derived from the pharynx

c. They both produce proteins that are bound with iodine

The arthropods are: pseudocoelomate/coelomate

coelomate

Segmentation of all 3 groups indicates a common ancestor

evolution from annelids and arthropods

The majority of all vertebrates are:

fish

The arthropods are: protostomes/deuterostomes

protostomes

The arthropods are: unsegmented/a. unsegmented/segmented

segmented

List 2 benefits of an amniotic egg.

· The shell keeps the egg from desiccating · The protection of the egg allows the animals to develop further prior to birth (direct development instead of indirect development requiring metamorphosis)

They have pharyngeal gill slits and a buccal diverticulum that looks like a proto-notochord

· They reshape the sediment of the seafloor due to activity and immense numbers of individuals · They are voracious predators and can greatly influence the distribution of other benthic species · They are important for keeping corals from becoming smothered by sediment or other harmful particles