What are the key concepts in the Bilateria lineage?5 points.

Cephalisation Compartmentalisation Development of organ systems The coelom SegmentationBIO2231 3ab

BilateriaWhat is Cephalisation?5 points.

Concentration of sense organs into a 'head' Associated with directional movement Directs sensory capabilities forward Development of the central nervous system (CNS) Longitudinal nerve chords evolve from a nerve net Increasing concentration of CNS in the head (brain) BIO2231 3ac

BilateriaWhat is Compartmentalisation?2 points.

Cephalisation is a case of specialisation of parts of the body for particular functions Separation of the body into specialised sections is a feature of the bilateral animalsBIO2231 3ad

DescribeThe development of the gut3 points.

Porifera : no gastrulation = no gut Cnidaria : gastrocoel is the gut and circulatory system (sac like sometimes with canals) Bilateria: Tube like gut develops from gastrocoel by the formation of an anusBIO2231 3af

What is Triploblastic?5 points.

Having a body derived from three embryonic cell layers. Ectoderm Mesoderm Endoderm The mesoderm is derived from the endoderm BIO2231 3ag

What are the different body plans of Bilateria?5 points.

Acoelomate Pseudocoelomate Coelomate Schizo- Entero- BIO2231 3aj

DescribeThe Coelom7 points.

Development of the body cavity Provides support for muscular action (therefore also related to directional movement) Functions as a hydrostatic skeleton (using fluid pressure in the coelom see Annelids later in the course) Facilitates increased body size Room for organ development and cushioning Diffusion of gases, nutrients, wastes into & out of organs Used for storage BIO2231 3ao

BIO2231 - Bilateria → Flatworms Flashcards by Andrew crisp

How are Cnidaria and Ctenophora distinguished from other Eumetazoa?

3 points.

Eumetazoa are divided into two major branches on the basis of BODY SYMMETRY

<ul><li>Cnidaria and Ctenophora are radially symmetrical </li><li>All other animals are (at least in some life stages) bilaterally symmetrical </li><li>The Bilateria generally have an ANTERO POSTERIOR axis</li></ul>

_{BIO2231 3aa}

How well did you know this?

Not at all

Perfectly

What are the key concepts in the Bilateria lineage?

5 points.

<ul><li>Cephalisation </li><li>Compartmentalisation </li><li>Development of organ systems </li><li>The coelom </li><li>Segmentation</li></ul>

_{BIO2231 3ab}

How well did you know this?

Not at all

Perfectly

Bilateria

What is Cephalisation?

5 points.

Concentration of sense organs into a 'head'

<ul> <li>Associated with directional movement</li> <li>Directs sensory capabilities forward</li> <li>Development of the central nervous system (CNS)</li> <ul> <li>Longitudinal nerve chords evolve from a nerve net</li> <li>Increasing concentration of CNS in the head (brain)</li> </ul></ul>

_{BIO2231 3ac}

How well did you know this?

Not at all

Perfectly

Bilateria

What is Compartmentalisation?

2 points.

<ul><li>Cephalisation is a case of specialisation of parts of the body for particular functions </li><li>Separation of the body into specialised sections is a feature of the bilateral animals</li></ul>

_{BIO2231 3ad}

How well did you know this?

Not at all

Perfectly

What is Gastrulation?

Gut formation

<div>One end of the embryo folds inwards, expands and fills blastocoel, producing layers of embryonic tissue ECTODERM & ENDODERM</div>

_{BIO2231 3ae}

How well did you know this?

Not at all

Perfectly

Describe

The development of the gut

3 points.

<ul> <li>Porifera : no gastrulation = no gut</li> <li>Cnidaria : gastrocoel is the gut and circulatory system (sac like sometimes with canals)</li> <li>Bilateria: Tube like gut develops from gastrocoel by the formation of an anus</li></ul>

_{BIO2231 3af}

How well did you know this?

Not at all

Perfectly

What is Triploblastic?

5 points.

Having a body derived from three embryonic cell layers.

<ul> <li>Ectoderm</li> <li>Mesoderm</li> <li>Endoderm</li></ul>

<ul> <li>The mesoderm is derived from the endoderm</li> <li></li></ul>

_{BIO2231 3ag}

How well did you know this?

Not at all

Perfectly

What is a Protostomia?

Early mesoderm cells form at junction between Ectoderm and Endoderm.

The mouth of the Protostomia (proto, “first”; stoma, “mouth”) develops from the first opening into the embryonic gut (blastopore)._{BIO2231 3ah}

How well did you know this?

Not at all

Perfectly

What is a Deuterostomia?

Early mesoderm cells form from buds off the embryonic gut.

<div>During development the mouth of deuterostomes develops from an opening into the embryonic gut other than the blastopore.</div>

<div>The blastopore develops into the anus. </div>

<div>The coelom (a fluid-filled body cavity lined with mesoderm) develops from buds off the embryonic gut.</div>

_{BIO2231 3ai}

How well did you know this?

Not at all

Perfectly

What are the different body plans of 
Bilateria?

5 points.

<ul> <li>Acoelomate</li> <li>Pseudocoelomate</li> <li>Coelomate</li> <ul> <li>Schizo-</li> <li>Entero-</li> </ul></ul>

_{BIO2231 3aj}

How well did you know this?

Not at all

Perfectly

What is an acoelomate?

A Protostomia where the Mesoderm fills blastocoel.

_{BIO2231 3ak}

How well did you know this?

Not at all

Perfectly

What is a pseudocoelomate?

A Protostomia where the Mesoderm lines one side of the blastocoel.

_{BIO2231 3al}

How well did you know this?

Not at all

Perfectly

What is a schizocoelomate?

A Protostomia where the band of mesoderm surrounds gut and then splits open.

_{BIO2231 3am}

How well did you know this?

Not at all

Perfectly

What is a Enterocoelomate?

A Deuterosomia

<div>The band of mesoderm surrounds the gut and opens</div>

<div>A similar form to schizocoelous but a different development process.</div>

_{BIO2231 3an}

How well did you know this?

Not at all

Perfectly

Describe

The Coelom

7 points.

Development of the body cavity

<ul> <li>Provides support for muscular action (therefore also related to directional movement)</li> <li>Functions as a hydrostatic skeleton (using fluid pressure in the coelom</li> <li>see Annelids later in the course)</li> <li>Facilitates increased body size</li> <ul> <li>Room for organ development and cushioning</li> <li>Diffusion of gases, nutrients, wastes into & out of organs</li> <li>Used for storage</li> </ul></ul>

_{BIO2231 3ao}

How well did you know this?

Not at all

Perfectly

Which phylums are Protostomia?

6 points.

<div>Lophotrochoza (spiral cleavage)</div>

<ul> <li>Platyhelminthes</li> <li>Mollusca</li> <li>Annelida</li> <li>Bryozoa</li></ul>

<div>Ecdysozoa (cuticle moulting</div>

<ul> <li>Arthropoda</li> <li>Nematoda</li></ul>

_{BIO2231 3ap}

Which phylums are Deuterostomia?

2 points.

<ul> <li>Chordata (Coelomates with endoskeleton, dorsal neural tube</li> <li>Echinodermata ( sea stars, sea urchins, sea cucumbers etc)</li></ul>

_{BIO2231 3aq}

What is Metamerism?

5 points.

= segmentation

<ul><li>A form of compartementalisation </li><li>Serial repetition of segments </li><li>Can involve internal/external structures </li><li>Linked to increased mobility </li><li>Allows complexity and specialised functions</li></ul>

_{BIO2231 3ar}

Describe

Bilateria - Tissues

4 points.

<div>Groups of similar cells + cell products organised to perform a specific function </div>

<ul> <li>Epithelial </li> <li>Connective </li> <li>Muscular </li> <li>Nervous</li></ul>

_{BIO2231 3as}

Describe

Bilateria - Organ systems

3 points.

<div>Compartmentalisation of the body at finer scales into organ systems </div>

<ul> <li>Digestive system - uptake of nutrients </li> <li>Circulatory system - move nutrients, respiratory gasses and waste products around </li> <li>Excretory system - osmoregulation and getting rid of waste products</li></ul>

_{BIO2231 3at}

Describe

Digestive systems

3 points.

Regionalisation of Gut (Foregut, Midgut & Hindgut)

<ul> <li>foregut and hindgut - ectodermal</li> <li>midgut - endodermal</li> <li>Local differences in pH and enzymes</li> <li>Mainly associated with one way gut with separate mouth and anus</li> <li>Provides "disassembly line" </li> <li>Typically physical breakdown, chemical breakdown, absorption, egestion</li></ul>

_{BIO2231 3au}

Circulatory systems

4 points.

<ul><li>Most basic form = circulation of fluid within the coelom </li><li>Intermediate form open circulatory system with contractile elements </li><li>Developed form closed system </li><li>Circulatory systems are usually less developed in small animals</li></ul>

_{BIO2231 3av}

Excretory systems

Function to remove waste products of metabolism Often linked to osmoregulation due to disposal of wastes in solution_{BIO2231 3aw}

What are Nephridia?

Ciliated tubules

<div>Nephridia remove metabolic wastes from an animal's body. Nephridia come in two basic categories: metanephridia and protonephridia.</div>

_{BIO2231 3ax}

Definition

Phylum Platyhelminthes

11 points.

Flatworms

Tissue organ organisation
Bilaterally symmetrical
Triploblastic acoelomate
Gastrulation

Digestive cavity (gut)
No anus!

Dorsoventrally flattened
Cephalized (head present)
Two major groups

Free living
Parasitic forms (show secondary loss of features)

_{BIO2231 3ay}

Describe

Platyhelminthes systems - musular system

Below the epidermis are layers of circular and longitudinal muscle fibres

_{BIO2231 3az}

Describe

Platyhelminthes systems - nervous

6 points.

Ladder shaped:

longitudinal nerve cords
transverse nerves
Cerebrial ganglia (brain)

Sensory organs:

Eye spots, statocysts

_{BIO2231 3ba}

Describe

Platyhelminthes systems - excretory

2 points.

Osmoregulation

A network of water collecting tubules adjacent to flame cells or protonephridia

_{BIO2231 3bb}

Describe

Platyhelminthes systems - Digestive

3 points.

Some species possess a digestive system
Mouth, pharynx and branching gut where nutrients are absorbed
Intestine: one opening, blind ending

_{BIO2231 3bc}

Describe

Platyhelminthes - outer body covering

2 points.

In free living forms: ciliated epidermis

Rhabdites (epidermal cells) produce mucous

Parasitic forms: non ciliated syncytial tegument

Resistance to immune system and/or gut enzymes

_{BIO2231 3bd}

Platyhelminthes

Class Turbellaria

12 points.

Almost all free living
Most are marine (planarians are freshwater)
Movement by ciliated epidermis and mucous
Muscle contractions permit turning, folding twisting and swimming
Nutrition

Live prey or dead animal remains
Muscular pharynx insert into prey and pump to bring in food fragments
Highly divided guts
Triclad and Polyclad

Branching of gut
Tri --: three main branches e.g., planarians
Poly --: many branches

_{BIO2231 3be}

Platyhelminthes

Superorder:Neodermata

10 points.

Flukes ( Trematoda & Monogenea )
Tapeworms (Cestoda)

Advantages

protected from predators
Reduced locomotion
Stable environment
Abundance of nutrients

Problems

How to stay in place? (i.e. avoid being physically removed)
How to resist host defences ? (digestive enzymes / immune system)
How to find a mate?
How disperse and locate another host?

_{BIO2231 3bf}

What is the tegument?

The integument of an organism, especially a parasitic flatworm

Integument = a tough outer protective layer, especially that of an animal or plant.

e.g. "this chemical compound is found in the integument of the seed"

_{BIO2231 3bg}

Describe

Class Trematoda

8 points.

Flukes

Tegument ( syncitial)
Layer of glycoproteins to avoid detection by host immune system
Possess 2 suckers

Oral sucker (feeding)
Ventral sucker (attachment)

Complex life cycles

Intermediate hosts
Molluscs > vertebrates

_{BIO2231 3bh}

What is a Schistosoma?

5 points.

Blood Fluke

Common blood fluke of SE Asia causes Schistosomiasis
Eggs penetrate intestinal tissue and bladder
Schistosomiasis (Bilharzia ) is a major infectious disease

400-600 million people infected
280,000 deaths/year

_{BIO2231 3bi}

Definition

Class Cestoda

6 points.

Tapeworms

Similar Tegument to Flukes

Body in two parts
Anterior Scolex for attachment (hooks & suckers)

Posterior series of proglottids (contain sex organs and eggs)
No digestive system !

Absorption of nutrients through body wall

_{BIO2231 3bj}

Describe

Other flatworm like things

4 points.

Nemertea (ribbon worms)

Possess a specialized coelom
through gut with anus
anterior mouth

Xenacoelomorpha (acoels , nemertodermatids, and xenoturbellids)

Flattened
acoelomates (an animal that does not possess a body cavity)
ventral mouth
no anus or discrete organs

_{BIO2231 3bk}