Zoology Lecture Exam 3 Dr. Siegfried SBU

metameric body

A ______ body plan has repeated segments.

Found in Phylum Annelida

protostomes

_______ develop via spiral cleavage and the blastomere becomes the mouth

T

T or F: A closed circulatory system is a characteristic for phylum Annelida

Dorsal suprapharyngeal ganglia

ventral nerve cord

Metanephridia (or protonephridia)

Name 3 internal physical characteristics found in Phylum Annelida

T

T or F: Metanephridia advances up to protonephridia when we get to earth worms

F: each segment has its own excretory, nervous and circulatory system

T or F: A metameric body plan shares a central excretory, nervous and circulatory system

T: A truly segmented body plan has both external and internal metamerism

T or F: In metameric body plans, segmented body parts occur externally and internally

septum

An earthworm starts out as an acoelomate and eventually becomes segmented by the growth of the ______

longitudinal and circular

Annelida have ____ and _____ muscles with a hydrostatic skeleton.

This allows for them to have a more advanced locomotion than Nemotodes.

isolates and minimizes injury

allows for modification of certain body regions

Name some benefits of having a metameric (segmented) body plan

hydrostatic

muscles

movement

Each segment in an earthworm is controlled individually. Name 3 ways it is controlled

tagmatization

________ is the specialization of body regions (organs) for specific functions

-Found in arthropods and some annelids

•Many hair

•Mostly marine

•Head has eyes with tentacles

•Parapodia with setae

•Monoecious or dioecious

Trochophore larval

Give some general characteristics of Class Polychaeta, Phylum Annelida

T

T or F: Class Polychaeta is most likely a polyphyletic group

parapodia

Paddlelike, lateral extensions that assist marine annelids in locomotion.

T

T or F: Class Polychaeta can be monoecious or dioecious with a trochophore larvae

Polychaeta

-modified parapodia

What Class does the Christmas tree worm belong to?

setae

Found in Phylum Annelid Class Parapodia, ______ are bristles secreted from parapodia that aid in locomotion

Rapidly crawling-14

Swimming-40

-Speed increases period and amplitude

If a sandworm were using 14 segments for locomotion, how fast would it be moving?

If a sandworm were using 40 segments for locomotion, how fast would it be moving?

Peristomium

______ is the first body segment that surrounds the mouth and bears sensory tentacles

Prostomium

The ______ of a Polychaeta is a lobe that projects dorsally and anteriorly to the mouth

cuticle

The epidermis of annelids consists of a single layer of columnar cells that secrete a protective, nonliving _____.

proboscis

The digestive system of most annelids is a straight tube that suspended by septa. The anterior region is modified into a ________

Pharynx, crop (storage sac), gizzard, intestine

Deposit-feeding polychaetes extract organic matter from the marine sediments injest. Their digestive tract consists of 4 primary organs. Name them

increased surface area

The respiratory gases of most annelids simply diffuse across the body wall with parapodia. What benefit would parapodia have in gas exchange and circulation

F: closed circulatory systems

T or F: Annelids have open circulatory systems

respiratory pigments

In an Annelids closed circulatory system, oxygen is usually caries in combination with molecules called ______ _____ which are usually dissolved in the plasma rather than contained in blood cells

•Pair of SUPRApharyngeal ganglia

-Run dorsoventrally along pharynx

•SUBpharyngeal ganglion

-Coordinate between segments

•Double ventral nerve cord

•Paired ganglion in each segment

Name the 4 main parts of an Annelids Nervous system

Dorsal aorta- rear to front

Ventral aorta- front to rear

Explain how blood travels in a Polychaetas body

subpharyngeal ganglia

The ________ coordinates movement between an Annelids different segments

segmental

In Annelids, the _______ ganglia coordinate swimming and crawling movements in isolated segments

supraphatyngeal

In Annelids, it is thought that the ______ ganglia control motor and sensory functions involved with feeding and forward locomotion

ventral

In Annelids, the ____ nerve cord contains giant fibers involved with escape reactions

They can determine which direction the light is coming from

Annelids usually have 2-4 pairs of eyes located on the prostomium. Some even have cuplike (concave) photoreceptors. What is the benefit to this?

Out of the 3 metabolic wastes, ammonia takes the least amount of energy to produce BUT it also needs the most amount of water to neutralize

Annelids excrete ammonia. What is a benefit AND drawback to this?

Protonephridium

•Tubule with closed bulb

•Connect outside other end

Metanephridium

•Open ciliated funnel

–Nephrostome

–Nephridiopore

-Intestine

The excretory organs of Annelids, like those of many invertebrates, are nephridia. Name the 2 types of nephridia Annelids possess

break points

Many Annelids have ____ _____ that allow worms to sever themselves when a predator grabs them.

T

T or F: Most Annelids can regenerate lost body parts

T

T or F: The majority of Annelids reproduce sexually

nephridiopore

Many Annelids release eggs through their _______

Epitoky

-Usually an epitoke has a body that is modified into two body regions where the anterior segments carry on normal maintenance and the posterior end is filled with gametes.

Formation of a reproductive individual (an epitoke) that is different than the nonreproductive form (an atoke). What is this called?

Oligochaeta and Hirudinea

Name the two Subclasses of Class Clitellata

Oligochaeta

This subclass of Annelida are primarily freshwater and terrestrial, lack parapodia and have few setae

-Earthworm

Earthworm

Lumbricus terrestris (Phylum Annelida) is commonly known as ______.

clitellum

Band of thickened, specialized segments in annelids that secretes a mucus ring into which eggs and sperm are released

F: They are monoecious, but always reproduce sexually via the exchange of sperms between animals

T or F: Since Oligochaetes are monoecious, they self-fertilize

Vesicles

receptacles

Seminal _______ are sites for maturation and storage of sperm. Seminal ______ receive sperm during copulation

typhlosole

Found in Earthworms, _______ is a large fold in the upper surface of the intestine of the earthworm that increases surface area to increase absorption

Hirundea

Phylum Annelida, Class _______ lacks parapodia and head appendages and most species lack setae. They always have 34 segments with secondary divisions called annuli. They are dorsoventrally flattened.

anterior

Oligochaetes have 1 or 2 testes and 1 pair of ovaries on the ______ segments of their body.

-The ovisacs hold eggs

F: They are monoecious, but cannot self-fertilize

T or F: Oligochaetes are hermaphroditic

T

T or F: In Oligochaetes, the clitellum forms into a cocoon for the deposition of eggs and sperm

Gippsland earthworm

Name this species

leeches

Unlike earthworms, _____ have oblique muscles which allows them to make "inch-worm" movements

Hirudin

Leeches secrete a anticoagulant called _______. This has been bio-mimicked for blood clots.

Paraphyletic

Based on this phylogeny, would you say that Polychaetas are a mono, para or polyphyletic group?

T

T or F: Mollusks are known as the first coelomates

Two-part body (head-foot and visceral mass)

Calcerous shell secreted by mantle

Mantle cavity

Bilarteral symmerty

Protostome characteristics (trochophore, reduced coelom, open circulatory system)

Radula

What are some characteristics of the Phylum Molluska?

visceral mass

In Mollusks, the _______ contains organs of digestion, circulation, reproduction, and excretion

Cephalopoda

All mollusks have an open circulatory system except one class. Name this Class

mantle

In Mollusks, the ______ attaches to the visceral mass, covers most of the body, and may secrete a shell

radula

The mouth of most mollusks possesses a rasping structure called a _____, which consists of a chitinous belt and rows of posteriorly curved teeth

pericardial sac

Mollusks possess a reduced coelom that surrounds the heart, nephridia and gonads. What other name is the reduced coelom known as?

Periostracum (outer, protein layer)

Prismatic (thickest layer made of Calcium carbonate)

Nacreous

What are the 3 layers of a Mollusks shell?

A grain of sand gets between the mantle and nacreous layer of a mollusk. This irritates the animal and they will secrete a material to cover the grain. However it will continue to irritate the animal so they will continue to secrete layers forming a Pearl.

How do pearls form?

mantle cavity

The space between the mantle and the foot is known as the ____ ____. This structure opens to the outside and functions in gas exchange, excretion and elimination

visceral mass

Which region of the Mollusk's body plan contains the digestion and reproductive organs?

odontophore

The radula overlies a fleshy, tongue-like structure supported by a cartilaginous _____. Muscles associated with this structure permit the radula to protrude from the mouth

F: This has been modified into a beak

T or F: Cephalopods have a radula

Gastropoda

Phylum Mollusks, Class ______ include the snails, limpets and slugs. They demonstrate torsion during early development and are the largest molluscan class. They are also an important host for trematode parasites

Torsion

______ is a 180 degree, counterclockwise twisting of the visceral mass, mantle, and mantle cavity.

1.Protect the head

-Foot enters last

2.Freshwater for gills

-Not dirty from crawling

3.Anterior sensory organs

-Stimuli in direction moving

Even though the adaptive significance of torsion in Gastropods is speculative, there are 3 plausible advantages to torsion. Name them

dextral, sinistral

If a snail'a shell has a right-handed coil, they are known as _____.

If a snail has a left-handed coil, they are known as _____

Fibonacci sequence

snails shells

________ is a sequence of numbers in which each number is the sum of the preceding two.

What animals display this?

Pro: Asymmetrically coiled shell makes it more compacts and less bulky for snail to carry around

Con: There has been a trade off between compact shell and room for organs. It is thought that Mollusk's ancestors had a pair, instead of single, organs

Name one pro and one con to a coiled shell

flattened foot with cilia

Gastropods use a ________ for locomotion

protostyle

The digestive tract of of gastropods, like that of most mollusks, is ciliated. Food is trapped in mucous strings and incorporated into a mucoid mass called the ______

Proboscis

Some predatory snails have a modified anterior portion that contains a _______ that contains the radula. This enables the snails to extract animals from hard to reach places.

siphon

-Some gastropods have an incurrent and excurrent siphon

In gastropods, gas exchange ALWAYS involved the mantle cavity. Primitive gastropods had tow gills; modern gastropods have lost one gill due to shell coiling. Some gastropods have a modified, rolled extension of the mantle called a ______.

T: During part of its circuit around the body, blood leaves the vessels and directly bathes cells in tissue spaces called sinuses.

T or F Gastropods, like most mollusks, have an open circulatory system

hydraulic skeleton

ex. tentacles

In addition to transporting nutrients, wastes, and gases, the blood of mollusks act as a ________ skeleton. This consists of fluid under pressure that may be confined to tissue spaces to extent body structure and to support the body

6 ganglia

Gastropods nervous system is characterized with ___ _______ located in the head-foot and visceral mass

cones

Gastropods have well developed sensory structures. Their eyes can be simple pits of photoreceptor cells or they may consist of a lens and cornea. What prevents gastropods from seeing in color?

Osphradia

In gastropods, _____ are chemoreceptors in the anterior wall of the mantle cavity that detect sediment and chemicals in the inhalant of water

T: This allows them to know which way is up by detecting the gravitational pull

T or F: Gastropods contain statocysts in their foot

nephridia

Modern Gastropods possess only one ______ that opens to the mantle cavity, or in land snails, on the right side of the body adjacent to the mantle cavity and anal opening.

nephridia

________ are excretory organs that filter fluid in the coelom

uric acid

ammonia

Terrestrial gastropods produce the metabolic waster, _______, in a semi-solid form to preserve water.

Aquatic gastropods produce ______ since they have an abundance of water.

Nudibranchs

______ are sea slugs that lack a shell and have exposed gills

protandric

Sometimes mollusks will come together to mate and their are too many of a certain sex. Some members will change their sex so that breeding may occur. What is this called?

valves

In molluscs, the two convex halves of the shell are called ____

Bivalvia (Pelecypoda)

Phyla Molluska, Class _____ includes clams, oysters, mussels and scallops. Each member is protected by two valves that are laterally compressed. They are filter feeders.

umbo

In Bivalves, the oldest part of the shell is the ______. This is a swollen area near the shell's anterior portion

Adductor muscle

In Bivalves, these muscles are located at either end of the dorsal half and keep the shell closed

nacre

If a sand grain lodges between the shell and the mantle of a Bivalve, the mantle will secrete _______ around the irritant, gradually forming a pearl

1.Metamerism modified by tagmatization

2.Chitinous skeleton

3.Paired, jointed appendages

4.Growth accompanied by ecdysis

5.Ventral nervous system

6.Reduced coelom to cavities surrounding gonads and sometime excretory systems

7. Open Circulatory system

8. Complete Digestive system

9. Metamorphosis often present

Name 9 general characteristics of the phylum Arthropoda

monophyletic

Arthropoda is a _______ taxon that is part of the protostome clade Ecdysozoa

Chelicerata, Myriapoda, Hexapoda, Crustacea, Trilobitomorpha (extinct)

The phylum Arthropoda is divided into 5 subphyla. Name them

F: They have MORE tagmatization

T or F: Just like Annelids, Arthropods demonstrate metamerism but they have less tagmatization

1. Metamerism

2. Exoskeleton

3. Hemocoel

4. Metamorphosis

Name 4 key features that has contributed to Arthropods success.