chordata quiz

Mesozoic is known as age of the ____

Reptiles

How are deuterostomes and protostomes different?

• Deuterostomes have radial cleavage, anus is formed from the blastopore, coelom formed via enteroceoly. All deuterstomes are ceolomates.

• Protostomia have spiral cleavage, mouth is formed from the blastopore, and coelom is formed via schizocoely (when the coelom is present).

How are deuterstomes and protostomia similar

Both are triploblastic

What are the three phyla in deuterostomia

• Echinodermata (closest related to hemichordara)

• Hemichordata

• Chordata *humans found here

What are the morphological features or echnodermata?

• Endoskleton 

  • A skeleton below a soft layer made of large plates (ossicles)

• Has a water-vascular system

• Basic pentaradial symmetry in adults

Why do echnioderms have pentaradial symmetry but fall within bilateria?

• Fossil record of echnioderms show they had bilateral symmetry

• At the larval stage present day fauna have bilateral symmetrical 

When did echinoderms diverge?

During the cambrian period

Where are echinoderms found?

• They are bottom dwellers

• Live in arine habitats because they arent strong osmoregulators, they avoid brackish and fresh waters

What are the five classes in echniodermata?

• Asteroidea

• Echinoidea

• Crinoidea

• Ophiuroidea

• Holothuroidea 

What do asteroidea eat?

• Benthic so they eat sessile prey

Describe morphological features of asteroidea

• A central disc with tapering arms coming from it

• The body is flattened, flexible and covered with a hardened epidermis

• Under the epidermis, there is an endoskeleton made up of small calcareous plates (ossicles)

• Ambulacral grooves running from the mouth to the tips of the arms (the vertical slits found ventrally on the star fish) 

Draw asteroidea

What body structure is a product of biomineralization?

ossicles

Describe morphological features of Ophiuroidea

• 5 slender arms that do not taper

• Central disc is pentagon shaped, very prominent

• Ambulacral grooves are closed and covered with ossicles

• Tube feet

Which two phyla are active predators?

• Asteroidea

• Ophiuroidea 

What are morphological characteristics of Echinoidea?

• endoskeleton with tests- sharp spiky protrusions 

• move via tube feet and muscular contraction

• benthic

What are morphological characteristics of Crinoidea?

• Calyx- body disc

• Five arms that branch into more frilly arms 

• Attached to a substratum for most of their life

• move via tube feet and muscular contractions

• suspension feeders- they eat food suspended in water

How do Crinoidea eat?

• They are suspension feeders, bringing food from the water column into their mouths

Describe morphological features of Holothuroidea?

• Greatly reduced ossicles

• Soft bodied

• Rely on tube feet and muscular contraction to move

• Mostly benthic, some pelagic

• Unique defense mechanis, when irritated they can case out part of their viscera (gut material) via  muscle contraction

How do holothuroidea eat?

• Suspension or deposit feeding

  • Eating sand, process sediment and excrete wast

What 3 characteristics distinguish echinodermata?

• Ossicles

• Water vascular system

• Pentaradial symmetry in  adults

Define Mass extinction

• Episodic events in which large numbers of taxa go extinct simultaneously 

When was the permian period

299-252 MYA

When did the permian mass extinction event take place?

252 MYA

Who was most impacted by the Permian Mass Extinction? What specific phyla?

• Shallow marine invertebrates because they could not move away, mainly marine life

• Trilobita, anthozoa, crinoidea

What characteristics do organisms who were most impacted by the permian mass extinction have in common?

• Aquatic, shallow waters

• Benthic

• Hard structures meaning they underwent biomineralization

What organisms emerged following the permian mass extinction?

• Complex chordates

The extinction of which phyla had the biggest impact on its environment and why?

• Rugosa. The result is the loss of reef building.

What order replaced rugosa following the Permian mass extinction?

scleractinia

What was the cause of this mass extinction?

Vollcanism. Pollution of air changes the greenhouse gases, warming the Earth and that warming resulted in increased ocean acidification. Quick climate change

What is the tethes?

Centralized shallow sea

Which groups proliferated after this extinction event?

• Non motile 

• Carbonate shells

• Organisms found at low latitudes, close to the equator

• chordates

What was the result of the eruption of the Siberian traps?

• Volcanic emissions of carbon dioxide, sulfide, halogen, and metals into the atmosphere

Why are the emissions of halogens detrimental?

They deplete the ozone rapidly, which increases UV radiation and causes acid rain

What was the shift in sea surface temperatures (SST)?

Estimated to have increased from 24-30 C to 35-39 C over 39,000 years. This change happened in such a short period of time that the fauna could not keep up.

How are sea surface temperatures measured?

Via oxygen in conodont apatite and branciopod calcite

What resulted from the sharp increase in sea surface temperatures?

• Anoxic events which made its way into shallow waters resulting in taxa suffocating. This extended for millions of years.

• Ocean acidification occurs 

• Organisms that make hard structures using calcium carbonate were especially susceptible to extinction and can only tolerate a specific pH

When did Chordata emerge?

• During the cambrian

Chordata have ____ species, but ____ morphologically diverse

less, more

What were chordata’s ancestors like?

Soft bodied with difficult ancestry to trace

What 5 characters distinguish chordata from all other animal phyla?

Notochord

Dorsal tubular nerve chord

Pharyngeal pouches and slits

Endostyle or thyroid gland

Postanal tail

Draw the body plan of a chordate, labeling their 5 key features

What is the function of the notochord?

• To provide a skeleton so muscles can attach to it. 

• Assists in undulation and swimming

• Stiffen the body

What is a notochord?

A flexible rod of fluid cells enclosed by a fibrous sheath, extending the length of the body

What is found in the dorsnal nerve chord?

The anterior end becomes enlarged to form the brain

What is the function of pharyngeal pouches and slits?

• Water and food particles are drawn by ciliary action through the mouth and flow out through the pharyngeal slits where food is trapped in mucus

• Water pases by the pharynx- simple vessels surrounded by connective tissue

What are pharyngeal slits?

• Openings that lead from the pharyngeal cavity to the outside

What is the difference between invertebrate and vertebrate chordates?

• Invertebrates draw water and food particles in via ciliary action through the moth and out of the pharyngeal slits where food is trapped in mucus

• Vertebtrates use muscular contraction to pump water through the pharynx

How did vertebrates develop internal gills?

• Vertebrates developed a capillary network, improving efficiency of gas transfer between blood and the water outside

What's the difference in the endostyle/thyroid gland between vertebrates and invertebrates?

• Invertebrates- the endostyle secretes mucus which traps small food particles brought into the pharygeal cavity making it an efficient filter feeding aparatus

• Verebrates- hormone secreter

What's the function of the postanal tail?

• Stiffening of the body plan, motility, and movement in water

What is the human version of the post anal tail?

• The coccyx

Draw the body plan of Chordata, labeling 5 key features

Protochordata is the subphylum of ____

Chordata

Tunicata is the subphylym of ____ 

protochordata

What is the tunicate

• A hard outer layer made of cellulose

What characteristics in the Tunicata body plan diminish over time?

• Notochord and tail and the dorsal nerve chord becomes reduced

Draw the tunicate body plan

• Must include the pharyngeal slits

• Endostyle

• Tunic

• Anus

• Heart

•  Mantle

• Incurrrent and excurrent siphon

How does tunicata eat?

• Endostyle secretes a mucous net to trap particles for consumption. Then the nutrients are absorbed in the gut and waste is expelled from the anus.

How does water pass through tunicata

• Water enters through the incurrent siphon and passes through a ciliated pharynx. Water pases through the slits into an atrium then out through the excurrent siphon.

Describe the tunicata circulatory system

• A ventral heart with two large vessels. Heart pumps blood in one direction for a few beats, then pauses, then drives blood the other direction

What chordate characteristics do adult tunicates exhibit?

• Pharyngeal slits and endostyle

What is the common name of phylym Cephalochordata?

lancelets

What are one of the species of Cephalochordata?

Amphioxus

How does Cephalochordata eat?

Food flows in through the mouth and into the pharynx where it's trapped by mucus. Food then passes through an atrium leaving the body by an atriopore.

Describe morphological characteristics of Cephalochordata?

• They have a circulatory system like a fish

• Have metapleural folds

• Lack a heart and fins