Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Zoology > Chapter 14: Phylum Platyhelminthes > Flashcards

Chapter 14: Phylum Platyhelminthes Flashcards

0
Q

Platyhelmithes are the ________ animals with bilateral symmetry. Their _______ is well defined. They are __________. They are also highly specialized_______.

A

simplest, mesoderm, triploblastic, parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What are the two major evolutionary advances ? (2)

A

-Cephalization - concentration of sense organs in anterior region
-Primary Bilateral Symmetry
I> body can be divided along only ONE plane of symmetry to yield two mirrored images of each other.
I> active, directed movement most efficient with an elongated body form with anterior, posterior, dorsal and ventral sides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Platyhelminthes are Acoelomates meaning>
space between the epidermis and digestive cavity?
atypical acoelomates>

A
  • have only one internal space, the digestive cavity
    L> between the epidermis and digestive cavity is filled with parenchyma
    -no digestive cavity!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Are Platyhelminthes acoelomate Protostomes or deuterostomes ?

A

Protostomes! their mouth develops first via blastopore !

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Some platyhelminthes are _______; others are _____.

The parasitic clades share an external body covering called a ___________. (also called ______)

A

free-living, parasitic, syncytial tegument, neodermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the four classes of Platyhelminthes?

A

Turbellaria, Trematoda, Monogena and Cestoda

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Class Turbellaria are mostly___________. Habitat wise they are mostly _______ dwellers in ________ or ________.
Freshwater planarians are found in? (3) Terrestrial flatworms are limited to ____________. (2)
All members of monogena and Trematoda and Ceatoda are ______?

A
  • free-living forms, bottom, marine, freshwater
  • freshwater planarians are found in streams, pools and hot springs
  • terrestrial are limited to moist places
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Epidermis and Muscles?

Most have cellular ________ on a basement membrane. Rod shaped ________ that swells and form a protective mucous sheath.

A
  • ciliated epidermis, rhabdites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Most turbellarians have dual-gland adhesive organs.These are?

A
  • viscid gland cells which fasten microvilli of anchor cells to substrate.
  • secretions of releasing gland cells provide a quick chemical detachment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Some turbellarians and others in this phylum have a Syncytial epidermis which is ?

A

-nuclei are not separated by cell membrane !

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Those that are not turbellarians lack _______ and have a ______

A

cilia and have a tegument

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Under the basement membrane there are what??(hint muscles) (3)

A

muscle fibres which run circularly, longitudinally and diagonally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Parenchyma cells fill spaces in the body which are mostly what?

A

non contractile portions of muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Nutrition and Digestion??? Cestodes have no _________ system.
Others in this phylum have a ______, _____, and ______.
In planarians the ________ may extend through the ventral mouth.

A

digestive, mouth, pharynx, intestine, pharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The intestine has how many branches?

A

three! one anterior and two posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The gastrovascular cavity is lined with what type of epithelium?

A

columnar!

16
Q

Characteristics of the mouth of trematodes and monogeneans? (3)

  • opens?
  • pharynx?
  • intestine?
A
  • opens near the anterior end
  • pharynx is not extensible
  • intestine ends blindly, varies in branching
17
Q

Planaria are carnivorous and detect food via ___________.
Food is trapped in ______________ from glands and _______.
They wrap themselves around prey
They extend the ________ to suck up bits of food.

A

chemoreceptors, mucous secretions, rhabdites, proboscis

18
Q

Monogeneans and Trematodes?
-Feed on what? (3)
-Proteolytic enzymes from the intestine are secreted for _______.
-Phagocytic cells in gastrodermis complete digestion at ________ level.
-Undigested food is egested out via _______.
Cestodes rely on the host’s ____________. They absorb the _______ nutrients.

A
  • host cells, cellular debris, and body fluids
  • extracellular digestion
  • intracellular
  • pharynx
  • digestive tract, digested
19
Q

Protonephridia?

  • flame cell?
  • excretory system occurs how?
  • osmoregulation?
A
  • osmoregulation
  • beating flagella drive fluids down collecting ducts
  • wall of the duct beyond the flame cell bears folds or microvilli to reabsorb ions and molecules
  • metabolic waste is removed via diffusion across the cell wall
  • collecting ducts join and empty at nephridiopores (mostly for osmoregulation…therefore absent in marine turbellarians)
20
Q

Marine Turbellarians lack Protonephridia b/c they have no need to expel _____?

A

excess water

21
Q

Monogeneans have two excretory pores. Location of each?

A
  • open laterally near anterior end

- flame cell protonephridia present also in the parasitic taxa.

22
Q

Ducts of tematodes open into ___________ that opens to a terminal pore.

A

excretory bladder

23
Q

Cestodes have two main excretory canals. Located?

A

one on each side.

metabolic waste is removed largely by diffusion through the body wall.

24
Q

Nervous System yo?

  • Subepidermal Nerve Plexus?
  • longitudinal nerve cords?
  • Fresh Water Planarians?
A
  • resembles nerve net of cnidarians, most primitive ns found in flatworms…turbellarians
    -one to five pairs of cords lie under the muscle layer…more derived worms have fewer nerve cords.
    -one ventral pair of nerve cords forming a ladder type pattern.
    I> brain is a bilobed ganglion anterior to the ventral nerve cords
25
Q

Neurons are organized into?(3)

A

-sensory, motor and association types…this is an important development in evolution of the NS

26
Q

Sense organs?

  • Ocelli( appear in what classes)
  • Tactile and Chemoreceptive cells
  • Statocysts
  • Rheoreceptors
  • sensory nerve endings are found in?
A
  • light sensitive eyespots… present in Turbellarians, Monogeneans and larval trematodes.
  • abundant, especially in the ear-shaped auricles
  • equilibrium
  • sense direction of water currents
  • the oral suckers and genital pores of parasitic groups
27
Q

Reproduction and Regeneration?

  • Fission-turbellarians?
  • Regeneration - retaining of polarity?
A

-turbellarians constrict behind the pharynx and separate into two animals ..each half regenerates missing parts….causes rapid pop growth..some do not separate right away making chains of zooids.
-if the head or tail are cut off…each end grows the missing part-retains polarity….
L>extracts of heads added to culture of headless worms prevents regeneration ..

28
Q

Some asexual reproduction occurs where?

A

in the intermediate host

29
Q

Nearly all are ___________ but cross fertilize.

A

monoecious

30
Q

Endoleicthal eggs with spiral determinate cleavage are _____ and ____

A

typical , ancestral

31
Q

Some turbellarians and all other groups have female gametes with little yolk. The yolk is contributed by the sex organ _____. What brings yolk cells to the zygote for ectolecithal development? A cleavage pattern cannot be distinguished. The zygote and yolk cells surrounded by eggshell move into the ____.

A
  • Vitellaria
  • Vitelline ducts
  • uterus
32
Q

Male structures?

  • testes connect to
  • vas defrens connect to? And run to ?
  • what is the copulatory organ?
A
  • one or more testes are connected to vasa efferentia that connect to one vas defrens
  • vas defrens run to a seminal vesicle
  • A papilla like penis or extensible cirrus is the copulatory organ
33
Q

Turbellarians develop both _____ and _____ organs opening at a _____ pore. After copulation, ____ and ____ enclose in small cocoon.
-what occurs next?plants, marine forms , embryos resemble?

A
  • male, female , common, yolk cells, eggs
  • attach by a stalk to plants
  • embryos emerge and resemble little adults
  • some marine forms are ciliated, free-swimming larvae
34
Q

Larval trematodes emerge as _________. Which penetrate a snail or eaten by a host.
Cestodes hatch only after being _______ ?
Trematoda, Monogenea and Cestoda are united into a single clade called?

A
  • ciliated larvae
  • consumed by a host
  • Neodermata

Zoology (55 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions