Invertebrates Flashcards
1
Q
what is an invertebrate
A
An animal without a backbone
2
Q
what phylum is involved in the earliest split in the animal tree
A
cnetophores
3
Q
what is the animal kingdom?
A
monophyletic
4
Q
what is meant by monophyletic
A
all share a common ancestor
5
Q
what 4 characteristics are clues to evolutionary relationships
A
fossils
gene sequences
patterns of embryonic development
morphology and physiology
6
Q
what are the 3 types of patterns of embryonic development
A
number of cell layers
fate of blastopore
cleavage patterns
7
Q
what are the two types of distinct cell layers that form in early development
A
diploblastic
triploblastic
8
Q
what is diploblastic
A
animals have 2 cell layers, ectoderm and endoderm
9
Q
what is triploblastic
A
animals have 3 cell layers, ectoderm, mesoderm and endoderm
10
Q
in triploblastic animals, what are the 2 development patterns after the blastopore forms
A
protostomes
deuterosomes
11
Q
what are protostomes
A
blastopore develops into the mouth
12
Q
what are deuterosomes
A
blastopore develops into the anus, the mouth develops later
13
Q
what is cleavage (cleavage patterns)
A
the first few divisions of a zygote
14
Q
what is the cleavage pattern in protostome development
A
spiral and determinate
15
Q
what is the cleavage pattern in deuterosomes
A
radial and indeterminate
16
Q
what is indeterminate cleavage
A
if cells are separated from each other, each has the potential to develop in to an entire organism on its own
17
Q
what is determinate cleavage
A
if cells are separated from each other, they will die. Neither has the potential to develop into an organism on its own
18
Q
how is spiral cleavage achieved
A
blastomere cells cleave obliquely (45 degree angle) to animal vegetative axis
19
Q
how is radial cleavage achieved
A
deutersosome cells cleave parallel or perpendicular to the animal vegetative axis
20
Q
what is an animals body plan
A
general structure, arrangement of organs and systems and integrated functioning of the body parts
21
Q
what are some key features of an animals body plan (2)
A
symmetry
body cavity structure
22
Q
what is an animals symmetry
A
its overall shape
23
Q
when is an animal symmetrical
A
if it can be divided into similar halves on at least one plane
24
Q
what are the 3 types of symmetry
A
spherical, bilateral and radial
25
what is spherical symmetry
body parts radiate from a central point and can be divided by an infinite number of panes
26
what is radial symnmetry
body parts arranged around one main axis at the body centre, can be divided into similar halves (4 section one)
27
what is bilateral symmetry
can be divided into mirror halves by one pane
28
what influences the way an animal can move
its body cavity structure
29
in what type of animal may a body cavity be present or absent
triploblastic
30
what are the 3 types of body cavity
coelomate
pseudocoelomate
aceolomate
31
what are coelomates
body cavity is a coelom that develops within the mesoderm and is lined with peritoneum
32
what advantage does being coelomate have
more control over movements of fluid in the body cavity
33
what are pseudocoelomates
body cavity is a pseudocoel, a fluid filled space in which organs are suspended
34
where are muscles located in pseudocoelomates
only on the outside
35
what are acoelomates
have no fluid-filled body cavity
36
what is the space between the body and guts of acoelomates filled with
mesenchyme cells
37
what is the hypothetical ancestor of animals
colonial flagellated protist
38
which two phyla show radial symmetry
cnidaria and cnetophora
39
what are the cnetophores
comb jellies
40
what kind of symmetry do ctenophores show
radial
41
describe the kind of cell layering in cnetophores
diploblastic
42
describe the gut and nervous system of ctenophores
complete cut and nerve cells (advanced)
43
what are ctenes
comb-like rows of cilia
44
how do ctenophores move through water
by beating cilia on ctenes
45
how do ctenophores feed
cells on feeding tentacles discharge adhesive material to capture prey
46
what phyla are basal in the animal tree
sponges (Porifera)
47
what phyla are grouped as placozoans
sponges
48
apart from sponges, all animals are grouped as
eumetazoans
49
what are bilaterians
a large monophyletic group
50
what 3 characteristics do all bilaterians share
bilateral symmetry
triploblastic
at least 7 HOX genes
51
what are protostomes divided into
2 clades - lophotrochozoans and ecdysozoans
52
how many phyla are in the kingdom stramenopila
6
53
where are stramenopiles found
aquatic and soil borne
54
what do the cell walls of stramenopiles have
cellulose
55
what separates stramenopiles from fungi
diploid life cycle
56
what are the 6 phyla of stramenopiles
```
diatoms
water moulds
golden algae
brown algae
red algae
green algae
```
57
what are diatoms (stramenopila)
Marine and freshwater planktonic algae
58
what are diatoms responsible for
20% of global carbon fixation
59
what are most species of diatom
photosynthetic
60
reproduction in diatoms is mostly ...?
asexual by binary fission
61
what are golden algae
freshwater multicellular or unicellular organisms
62
what are water moulds similar to
fungi
63
what kind of conditions do water moulds require to thrive
very moist
64
what does sexual reproduction in water moulds produce
the oospore, which is a thick walled resting spore that is female
65
what are phytopthora
a genus of plant damaging oomycetes
66
what is the scientific name for potato late blight
phytopthora infestans
67
what is an example of potato late blight
irish potato famine of the 1840s
68
what is phythium
genus of parasitic oomycetes
69
what are 2 examples of phythium
root rot of plants growing in moist conditions
| skin infections on mammals
70
what are peronospora
downy mildews
71
what are 3 features of peronospora
obligate parasites
branched, determinate sporangiophores
sporangiophores protrude through host stomata
72
what is saprolegnia
elongated terminal sporangia
73
identify 3 features of saprolegnia
more than one egg per oogonium
abundant in water courses
can exist saprotrophically
74
what do saprolegnia effect
pathogens on fish, amphibians and invertebrates
75
give an example of a saprolegnia
white fin disease of fish
76
what are sargassum species of brown algae
free living forms
77
what are protists
eukaryotes that are neither plants, fungi or animals
78
protists do not constitute a clade therefore are....
paraphyletic
79
what is paraphyletic
descend from a common evolutionary ancestor, but not including the descendant groups
80
identify 3 former classifications of protists
protozoa
algae
fungal types
81
what are yeasts and seaweeds classified as
protists
82
what are chromalveolates
protists that play an important role in the carbon cycle in oceans
83
what do chromalveolates form
marine sediments
84
what is responsible for shellfish poisoning and rumination and some parasitic diseases in animals and plants
chromalveolates
85
what are alveolates/apicomplexans
obligate parasites that are intracellular
86
how do alvealates/apicomplexans reproduce
by spores/sporozoites
87
what is malaria an example of
an alveolate/apicomplexan
88
what is plasmodium falciparum
a severe and complicated form of malaria that infects young children and the non-immune
89
what are p.vax, p.ovale and p.maloria
types of malaria that are benign, uncomplicated and chronic
90
following acute infection in either p.vax, p.ovale or p.maloria what happens
chronic infection
91
following acute infection in plasmodium falciparum what 2 things may happen
death
| cerebral malaria - coma, convulsions
92
what is toxoplasma
an apicomplexan disease that results from infection with the toxoplasma gondii parasite
93
what are excavates
some very serious human diseases
94
what are kinetoplastids
unicellular parasites with one or two flagella and a single mitochondrion
95
what does the mitochondrion of kinetoplastids contain
a kinetoplast
96
what is a kinetoplast
a structure with multiple, circular DNA molecules and proteins
97
what are trypanosomes
kinetoplastids
98
what causes African Sleeping Sickness
African trypanosome
99
what is the vector of sleeping sickness
tsetse fly
100
what is the early stage of African sleeping sickness called
haemolymphatic
101
what is the treatment for the heamolymphatic stage of African sleeping sickness
suramin and pentamadine
102
what does the late stage of African sleeping sickness effect
CNS
103
what is the treatment for the late stage of African sleeping sickness
melarsoprol and NECT
104
what are phytomonas
a genus of trypanosome that infect plant species
105
what do Phytomonas cause
sudden wilt of plants
106
what are the 2 apicomplexan examples
malaria and t.gondii
107
what are the 2 trypanosome examples
African sleeping sickness and phytomonas
108
what is the phylum porifera
the sponges
109
what are sponges in the phylogeny of animals
a sister group to animals but still a basal group in the phylogeny
110
what are sponges
an aggregation of cells around a water canal system
111
can sponges move
no, they are sessile
112
how do sponges bring water in to their water chanel
by beating choanocyte flagella
113
what do choanocytes in sponges do
capture food particles from the water
114
what are sponges closely related to
colonial protists
115
what are the adults of sponges
colonial
116
what are the larvae of sponges
free-swimming
117
what are the body forms of sponges adapted to
water currents and waves
118
describe the cell layers in sponges
no distinct embryonic cell layers or true organs, but do have several cell types
119
describe the symmetry of sponges
no characteristic symmetry
120
what are the body cells of sponges
totipotent
121
what is totipotent
capable of giving rise to any cell type
122
describe the nervous system of sponges
no nervous system, with little coordination between cell types
123
describe the gut and body cavity of sponges
no gut
| internal space, no body cavity
124
identify the 5 cell types that make up sponges
```
spongocoel
choanocytes
mesohyl
pinacoderm
porocyte
```
125
what do pinocytes form in sponges
the pinacoderm
126
what is the role of the pinacoderm in sponges
take up food by phagocytosis
127
what do porocytes form in sponges
ostia
128
what is the ostia in sponges
incurrent pore
129
what is the name of the skeletal elements of sponges
spicules
130
what does the spicule skeleton of sponges do
discourage consumption by predators
131
what are the 3 classes of sponges
calcerea
desmospongia
hexactinellida
132
what are the class calcera within sponges
calcerous sponges
133
what are the 3 forms of sponges
asconoid
leuconoid
synconoid
134
what forms do calcerea sponges come in
asconoid
synconoid
leuconoid
135
what forms do desmospongia sponges come in
leuconoid
136
what is incompatible with efficient food particle capture in sponges
rapid water movement
137
what do the different forms of sponges differ in
diameter of water channel
138
what is the order of efficiency in the forms of sponges
asconoid
synconoids
leuconoids
139
how do sponges reproduce
both sexually and asexually
asexually - budding or fragmentation
sexually - cross-fertilisation by synchronous release of sperm
140
what are the body parts of a sponge
ostia
oscula
internal space
spongocoel
141
what is the oscula in sponges
excurrent pore
142
how do sponges demonstrate Bernullis' principle
efficient water flow and feeding
143
what is included in the phylum cnidaria
Jellyfish
Anemones
corals
144
what is the phylum cnidaria often called
the stinging thread
145
what does the stinging nature of cnidaria allow
to take prey
146
describe the cell layers of cnidaria
Diploblastic
147
what are the 2 cell layers in cnidaria
epidermis
| gastrodermis
148
what is between the 2 cell layers in cnidaria
mesoglea
149
what clade do cnidaria belong to
eumatozoa
150
what are characteristics of the clade eumatozoa
true tissues, no organs
151
describe the nervous system of cnidaria
have nerve nets and muscle cells
152
what is metagenesis
can live as 2 forms
153
what phylum show metagenesis
cnidaria
154
what are the two forms of cnidaria (metagenesis)
polyp
| medusa
155
what are the medusa form of cnidaria
free-swimming form that show sexual reproduction
156
what are the polyp form of cnidaria
sessile form that show asexual reproduction and adhere to substrates
157
what does the medusa form of cnidaria look like
upside-down polyp with a thicker ectoderm
158
what kind of gut do cnidaria have
blind gut sac, gastrovascular cavity with a single opening
159
what is a blind gut
an incomplete gut
160
what function does the single opening of the cnidarian gut have
mouth and anus
161
what does the gastrovascular cavity of cnidarians do
functions in digestion, circulation, gas exchange and as a hydrostatic skeleton
162
what are cnidocytes
the stinging cells found in the tentacles of cnidaria
163
what do cnidocytes function in
defence and capture of prey
164
what do cnidocytes contain
organelle like structures called cnidae
165
what are cnidae
tubule or thread that may deliver toxins, stick to prey or entangle an object
166
what are the 3 types of cnidae in cnidaria
nematocyst
spirocyst
ptychocysts
167
what are nematocysts
double walled capsule that delivers toxins
168
what are spirocysts
single walled capsule, adhesive in nature
169
what are ptychocysts
taxonimically restricted to ceriantheria, lacks spines and is strictly adhesive
170
what do nematocysts contain
cnidocil
operculum
stinging thread
171
what is the cnidocil of nematocysts
the trigger to sting that opens the operculum
172
what happens when the operculum of nematocysts in open
water rushes in and forces the thread out at high speed to due the built up pressure
173
what are the 4 classes of cnidaria
Hydrozoa
Scyphozoa
cubozoa
anthozoa
174
what are different in every species of cnidaria
their nematocysts
175
Describe the form of Scyphozoa
predominantly medusa over polyp form. but there is a polyp stage
176
describe the mesoglea of Scyphozoa
thick and firm giving rise to the name jellyfish
177
what is absent in jellies living in the open ocean
polyp stage
178
describe the medusa adults of scyphozoa (reproduction)
either male or female and release either sperm or ego reproduce
179
what are the 2 reproductive strategies of Scyphozoa cnidaria
can either bud or strobilla
180
what are most Hydrozoa cnidarians
marine colonial animals
181
what do most lifecycles of Hydrozoa cnidarians
alternative polyp and medusa forms
182
what is the best known hydrozoan cnidarian
hydra that exists in only polyp form
183
how can hydrozoan cnidarians reproduce
both sexually and asexually without having a medusa form
184
what do colonies of hydrozoan cnidarians do
they are interconnected and share a continuous gastrovascular cavity
185
give an example of a hydrozoan cnidaria
Portuguese man-of-war
186
what do polyps within colonies of hydrozoan cnidarians do
differentiate to perform specialised function such as digestion
187
what is the dominant form in cubozoa cnidarians
medusa with square shape
188
what do cuboxoa cnidarians have
4 evenly spaced tentacles and well developed eyes
189
what is an example of cubozoa cnidarians
box jellyfish
190
what are the 2 subclasses of anthozoa cnidarian
hexacorallia
| octocorallia
191
what is the important order within hexacorallia anthozoans
scleractinia
192
what are anthozoans
hard corals
193
what are hermatypic scleractinian corals
reef forming corals
194
what do the polyps of hermatypic scleractinian corals do
secrete a matrix of organic molecules on which they deposit calcium carbonate, which forms the skeleton
195
where do corals grow
clear and nutrient-poor waters
196
what do hermatypic scleractinian corals possess
photosynthetic dinoflagellate called zooanthellatae as endosymbioants
197
what do the zooxanthellae in hermatypic scleractinian corals do
increase calcium carbonate deposition rate
198
where are reef forming corals restricted to
clear surface waters with enough light to support photosynthesis
199
what are the 2 types of scleractinian corals
hermatypic
| atlermatipic
200
what are atlermatipic scleractinian corals
non reef building corals
201
what do atlermatipic scleractinian corals lack
zooxanthellae
202
where are atlermatipic scleractinian corals be found
deep, cold waters
203
identify 2 reasons why coral reefs have an ecological and economic importance
provide a CO2 cleansing service
undiscovered species are key to new medicines
204
identify 2 threats to coral reefs and their impact
global warming- elevated co2 levels accelerate bleaching
polluted runoff- excess nitrogen can lead to outgrowths of algae, which smother coral
205
identify 2 ways to try and protect coral reefs
monitor reef temperatures
| legal system - marine protected areas
206
what super phylum to Platyhelminthes belong to
lophotrochozoans within protostomes
207
Platyhelminthes display a variety of body forms, but what are all of them
dorso-ventrally flattened
208
what are the 2 habitats of platyhelminthes
free-living flatworms
| internal parasites
209
what do free-living flatworms show
cephalisation
210
what is cephalisation
paired sense organs in the head
211
how do free-living flatworms move
glide over surfaces by broad bands of cilia
212
what 2 things are included in internal parasites
flukes and tapeworms
213
how do internal parasites gain food
absorb food from the digestive tract of the host
214
what do many internal parasites lack
a digestive tract of their own
215
what kind of body cavity do Platyhelminthes have
acoelomate
216
describe the number of cell layers in platyhelminthes
triploblastic
217
what is the only internal cavity in Platyhelminthes
the gut
218
what is the symmetry found in Platyhelminthes
bilateral
219
what aided the first hunters (Platyhelminthes)
bilateral symmetry
| cephalisation
220
describe the cleavage of Platyhelminthes
spiral and determinate
221
what does the dorso-ventrally flattened nature of Platyhelminthes mean
they have no gas transport system so respiration is by diffusion
222
why is the flat shape of Platyhelminthes necessary
no cell can be too far from the outside as they respire by diffusion due to a lack off body cavity
223
describe the digestive tract of Platyhelminthes
mouth opens to a blind gut
224
why is the digestive tract of Platyhelminthes often highly branched
to increase surface area for absorption of nutrients and transport of food to all parts of the body
225
describe 3 characteristics of Platyhelminthes reproduction
most are hermaphroditic
internal fertilisation
complex sex organs
226
describe the nervous system of Platyhelminthes
simple nervous system with central ganglion with pairs of longitudinal nerves connected by transverse nerves
227
compare the sensory system of free-living and parasitic flatworms
free-living - well developed
| parasitic - less elaborate
228
what are the simplest animals with an excretory system
Platyhelminthes
229
what phylum contain a protonephridial system
platyhelmihtes
230
what does the prptonephridial system of Platyhelminthes consist of
ciliated flame cells
231
what is the purpose of the protonephridial system in Platyhelminthes
exretes waste and is also important for osmotic balance
232
what do some species of platyhelminths have (sensory)
ocelli
233
what are ocelli
simple eyes
234
what are the 4 classes of platyhelminth
turbellaria
cestoda
trematoda
monogeneans
235
what are the 2 characteristics that determine between the classes of Platyhelminthes
form of gut - present, absent, simple, branched and pattern of branching
pharynx - simple, folded or bulbous
236
what are turbellaria
free-living flatworms
237
what do Turbellaria Platyhelminthes prey on
bacteria to medium sized invertebrates
238
what do Turbellaria Platyhelminthes have that that helps them find prey
well developed sense organs
239
what are rhabdocoela platyhelminthes
have simple/no gut and a simple pharynx
240
what are triclad Platyhelminthes
have 3 branched intestines
241
what are polyclad Platyhelminthes
highly branched intestine and folded pharynx
242
what are 3 features of Turbellaria Platyhelminthes
simple lifestyle
amazing regenerative powers
both sexual and asexual reproduction
243
how do Turbellaria Platyhelminthes reproduce asexually
fission/clone themselves by transverse or Lon gitudional division
or budding
244
how do Turbellaria Platyhelminthes reproduce sexually
simultaneous hermaphrodites, fertilise eggs internally by copulation
245
what is an example or a Turbellaria Platyhelminth
New Zealand flatworm
246
what is the New Zealand flatworm a predator of
earthworms
247
identify 3 adaptions to parasitism Platyhelminthes have
sensory capability for host finding
resistant life stages
variable and complex life cycles
248
what are monogea Platyhelminthes
external flukes
249
what are most monogea platyhelminthes
ecto-parasites of fish
250
what do monogea Platyhelminthes have that makes them well adapted to paraitism
organs of attachment - suckers, clamps and hooks
251
describe the life cycle and reproduction of monogea Platyhelminthes
simple without asexual phases
252
give and example of a monogea platyhelminth
monogenean skin/salmon fluke
253
what is an issue associated with the monogenean skin/salmon fluke
serious fish aquaculture problem
254
what are trematoda
internal flukes
255
what are the bodies of trematode Platyhelminthes similar to
leeches with suckers at both ends
256
what do trematodes consume
host tissue
257
what is an example of a trematode platyhelminth
blood fluke
258
what disease in humans do blood flukes cause
schistosomiasis
259
what kind of life cycle do blood flukes have
indirect 2 host lifecycle with sexually reproductive stage in humans and asexual stage in molluscs
260
what are Cestoda Platyhelminthes
internal parasites eg tapeworms
261
describe where Cestoda Platyhelminthes are found
alimentary tract of vertebrates
262
identify 2 defining characteristics of Cestoda
scolex
| proglottids
263
what is the scolex of Cestoda Platyhelminthes
anterior attachment organ
264
what are the reproductive units of Cestoda Platyhelminthes
proglattids
265
what does each proglottid contain
several ovaries and 1000 distinct testes
266
what are the 2 tapeworms that infect man
beef
| pork
267
what does the mesoderm allow for in platyhelmithes
formation of more elaborate organs - simple nervous and osmoregularity systems
268
what do the phylum annelids come under
spirilian lophotrochozoans
269
what do annelids which is unique to them
segmentation
270
what does segmentation in annelids allow
better locomotion by individual movement of separate segments
271
what does the evolution of a more sophisticated nervous system in annelids allow
fine control of movements
272
describe the body cavity of annelids
true coelom made of schizocoel - except leeches
273
what kind of symmetry do annelids have
bilateral
274
what type of cleavage to annelids have
spiral
275
what do most annelids have on their body surface
chitenous bristles
276
what 2 things may the chitenous bridles of annelids be
setae or chetae
277
what varies in annelids
degree of chephalisation
278
describe the nervous system of annelids
development of a centralised nervous system with a brain and ganglions all down length
279
describe the circulatory system of annelids
closed
280
what is a closed circulatory system
have a heart, arteries and blood vessels
281
what are the bodies of annelids coated with
a thin, secreted permeable wall
282
how do annelids respire
gas exchange through skin, gills or parapodia and polychaetes
283
what restricts annelids to moist environments
they respire through gas exchange from skin, gills or parapodia
284
what is present in each segment of annelids that helps remove waste and maintain osmotic balance
excretory systems
285
what is a mete mere in annalids
a segment
286
what are annuli in annelids
external circular grooves
287
what are septa in annelids
internal divides between segments
288
what does the presence of septa in annelids cause
multiple enclosed coeloms
289
what are the 3 things that continue through the entirety of an annelids body
nerve chord
blood vessels
intestine
290
what are the 2 classes of annelids
polychaeta
| clitella
291
what are the largest group of annelids
polychaetes
292
what may polychaete be (2)
free-swimming (erant) or sedimentary
293
identify 3 main characteristics of polychaetes
well developed head
parapodia on each segment
many stiff bristles
294
identify 3 things a well developed head gives to polychaetes
eyes
tentacles for prey capture or filter feeding
possibly jaws
295
what are parapodia of polychaetes
extensions of the body wall
296
what do parapodia function in
gas exchange as gills and movement
297
how are setae arranged in polychaetes
bundles on parapodia usually
298
identify a family within the polychaetes
pogonophorans
299
what have pogonophoran lost that other annelids have
digestive tract
300
what do the class clitella lack that polychaetes have
parapodia
301
what is unique to the class clitella
the reproductive organ the clitella
302
what are the 2 sub-classes within the class clitella
oligochaete and hirudinea
303
what subclass of clitella do earthworms belong to
oligochaete
304
what are oligochaetes
terrestral and freshwater segmented worms
305
identify 3 characteristics of oligochaetes
reduced head
no parapodia, eyes or tentacles
few setae
306
what does the clitellum function in
reproduction in clitella
307
what sub-class of clitella do leeches belong to
hirudinea
308
what do hiridinea lack
setae
parapoida
tentacles
309
what is unique in the phylum to hirudinea
anterior and posterior suckers
310
what do the anterior and posterior suckers in hirudinea function in
temporary anchors that and movement
311
in what subclass of annelids is the colom not segmented
hirudinea
312
what are leeches
ectoparasites
313
what do leeches do to hosts
make an incision and secrete an anticoagulant and feed on blood
314
how do oligochaetes move
lengthen and shorten body
lengthen - circular muscles contract
shorten - longitudinal muscles contract
315
what is the constant fluid volume in oligochaetes called
hydrostatic skeleton
316
what types of muscles are present in hirudinea
circular
longitudinal
diagonal
dorsoventral
317
what is unique about the coelom on hirudinea
it is reduced due to the loss of septa dividing the coelom and the space is taken up by extra muscles
318
why are setae absent in hirudinea
they do not burrow
319
how to hirudinea move
anterior and posterior suckers alternatively anchor to substrate
320
what is the main form of reproduction in polychaetes
sexual
321
how can polychaetes reproduce
both sexually and asexually
322
how do polychaetes carry out asexual reproduction
fragmentation
323
where are the gametes of polychaetes produced
peritoneal tissue
324
how to oligochaetes reproduce
they are hermapohroditic but mainly reproduce sexually by external fertilisation using clitellum
325
how do hirundinea reproduce
simultaneous hermaphroditic with internal fertilisation
326
when is the clitellum visible in oligochaetes
always
327
when is the clitellum visible in hirudinea
only during the reproductive season
328
what does the clitellum do during copulation
holds worms together while each gives and relieves sperm
329
what do worms do after mating
each secrets a mucus cocoon, depositing eggs with the sperm
330
what are nematodes
the round worms
331
where can nematodes be found
everywhere
332
name 3 unusual locations of nematodes
vinegar
beer mats
hot springs
333
what do nematodes parasitize
almost every type of plant and animal, including humans
334
what clade are nematodes in
ecdysozoans within protostomes
335
what is the major innovation of ecdysozoans
development of a sturdy ectoskeleton
336
what must occur for nematodes to grow
cuticle must be melted and replaced with a larger one
337
how many times does nematode most its cuticle as it grown
4
338
describe the segmentation in nematodes
unsegmented
339
describe the symmetry in nematodes
bilateral
340
describe the cell layers in nematodes
triploblastic
341
describe the nervous system of nematodes
well developed
342
what is absent in nematodes (circulation)
no vascular blood system so diffusion and osmosis circulate nutrients and waste products throughout the body
343
what do the cuticle and body cavity of nematodes do
maintain shape
344
what is the cuticle in nematodes
a protective layer that provides some body support
345
what does the cylindrical shape of nematodes mean
it cannot respire exclusively via diffusion as tissues are too far from the exterior
346
what solves the problem of respiration not being exclusively by diffusion in nematodes
pseudocoelom
347
what does the presence of a pseudocoelom in nematodes do
distributes gas and nutrients to body through gut wall and collects waste
348
as well as the cuticle and body cavity, what also. maintains the shape on nematodes
hydrostatic skeleton
349
what muscles are present in nematodes for locomotion
only longitudinal, arranged in 4 zones
350
how do nematodes move
by undulations or wave-like motions of the body
as 1 segment contracts it pulls the remainder of the body forward
351
what do nematodes require for movement
a film of moisture
352
what is correct about the sexes in nematodes
they are usually separate and sexual dimporphism is often seen
353
can nematodes by hermaphroditic
yes
354
describe the reproductive process in nematodes
eggs deposited by female, embryo develops, juvenile hatches from egg
355
how many juvenile stages are present in nematodes
4
356
what are etomopathogenic nematodes
beneficial nematodes
357
what do many etomopathogenic nematodes form
mutualistic symbioses with insect pathogenic bacteria
358
what can etomopathogenic nematodes be used as
effective bio-control methods on pests
359
identify 4 examples of human parasites (nematodes)
ascariasis
hookworm
pinworm
filarial nematodes
360
what do the life cycles of parasitic nematodes have
cyst stages that transfer to new hosts or intermediate life cycles using vectors or intermediate hosts
361
what is the example ascariasis
human intestinal roundworm
362
how is the human intestinal roundworm transmitted
by eggs in soil
363
how do hookworms gain blood meal
burrow their anterior hook into intestines of man
364
what is similar about the lifecycle and transmission of the human intestinal roundworm and hookworm
direct
365
what human disease does the filarial nematode parasite cause
elephantiasis
366
what is the vector of the filarial nematode parasite
mosquitos
367
where do adult pinworms live
large intestine
368
how do female pinworms lay eggs
migrate to anal region at night and deposit eggs
369
how are pinworms avoided
good hygiene
370
what occurs in all soils and marine sediments
nematodes
371
what is a famous nematode model organism
C.elegans
372
what is C.elegans a model organism for
genetics
| developmental research
373
what was the first animal to have its entire genome sequenced
C.,elegans
374
identify 3 reasons why nematodes are so successful
have environmentally protective cuticle
biochemical adaptions to existence in extreme condtiooms
use a variety of reproductive strategies
375
compare the shape of flatworms, roundworms and annelids
flatworms - flattened
roundworms - cylindrical with tapering ends
annelids - cylindrical with tapping ends
376
compare segmentation in flatworms, roundworms and annelids
flatworms - no
roundworms - no
annelids - yes
377
compare the body cavity of flatworms, roundworms and annelids
flatworms - acoelomate
roundworms - pseudocoelomate
annelids - coelomate
378
what is the most diverse group of lophotrochozoans
molluscs
379
what are the second largest phyla after arthropods
molluscs
380
how many classes of molluscs are there
7
381
why are molluscs important to man
food
medicine
agriculture
382
what is the fate of the blastopore in molluscs
protostome
383
what kind of cleavage do molluscs have
spiral
384
describe the symmetry in molluscs
bilateral
385
describe the number of cell layers in molluscs
triploblastic
386
describe the body cavity of molluscs
coelomate
387
describe the segmentation in molluscs
unsegmented
388
what are the 3 main components of the generalised molluscan body plan
head-foot
visceral mass
mantle
389
what does the mantle do in most aquatic species
extend beyond visceral mass to form a mantle cavity
390
what does the mantle enclose
a water space within are gills for gas exchange
391
what in molluscs creates a water current
cilia on gills
392
what feature do the gills of molluscs have
they are highly vascularised for gas exchange
393
what do some species of molluscs use gills for that isn't gas exchange
filter feeding
394
what is the radula of molluscs
an essential feeding organ
395
what does the circulatory system of all molluscs except cephalopods consist of
heart
| haemocoel - open circulatory system
396
what form does the coelom of molluscs take
a small chamber around the heart
397
describe the sexes of most molluscs
distinct
398
how do aquatic molluscs reproduce
external fertilisation
399
what is the name of marine mollusc, free-swimming larvae
trochophores
400
what do most marine snails and bivalves have (stage)
veliger stage
401
what is the veiled stage in molluscs
a 2nd free-swimming larval stage
402
what are the 3 classes of molluscs studied
gastropods
bivalvia
cephalopods
403
what are gastropods (4)
snails, slugs, nudibranchs and limpets
404
how do most gastropods move
by gliding on the foot
405
what do most garotopods have that are located dorsally
shells
406
what species of gastropod have lost their shells
slugs
407
identify 3 features of gastropods
prominent head
well developed sensory structures
radula for feeding
408
describe the died of gastropods
herbivores or predatory carnivores
409
describe the sex of gastropods
hermaphroditic
410
what was the key adaption of gastropods that allowed them to colonise land
internal fertilisation
411
describe the shell of gastropods
single shell
| usually coiled
412
where is the visceral mass of gastropods located
inside the shell and rotated 180 degrees during development (torsion)
413
where is the mantle cavity located in gastropods
forward over head
414
what did torsion allow in gastropods
spiral coiling of shell
415
identify the 3 sub-classes of gastropods
Prosobranchia
opisthobranchia
pulmonate
416
what 2 species are in prosobranchia
conchs
| cone snails
417
what are included in opisthobranchia
nudibranchs
418
describe the sex of nudibranchs
hermaphrodites
419
what are included in pulmonata
snails and slugs
420
what are the only molluscs that live in a terrestrial environment
snails and slugs
421
describe the development of pulmonata
direct, no larvae
422
what are the most highly evolved class of molluscs
cephalopods
423
what are the two main sub-classes of cephalopods
nautiloidea
| coleoidea
424
what is the diet of cephalopods
carnivores
425
what feature of cephalopods helps catch prey
arms or tentacles with suckers
426
what feature of cephalopods tears food
radula
427
how do cephalopods swim
by means of jet propulsion using the modified mantle and siphon
428
what is fused to the foot in cephalopods
head
429
what did primitive cephalopods possess
a shell
430
what are the only extant members of the cephalopod phylum with a shell
nautilus
431
what happened to the molluscan shell in coleoidea
has been internalised of absent
432
describe the sexes in cephalopods
sexes seperate
433
what is modified in male cephalopods for spermatophore transfer
one tentacle known as the hectocotylus
434
how do cephalopods reproduce
males insert their hectocotylus into the mantle cavity of the female, near or within the oviduct
435
identify 2 tricks male octopus have to survive the mating process
keep at arms length - male has very long hectocotylus
detached arm - sexual dimorphism in blanket octopus
436
describe the development of cephalopods
direct - after hatching they look like mini adults
437
describe the sense organs (eyes) of cephalopods
well developed
| camera type eye that is able to focus
438
describe the power of swimming in nautilus
poor swimmers, with weak propulsion from the siphon
439
how many tentacles do nautilus have that are modified for transferring spermatophores
4
440
how many suckers do nautilus have that bear suckers
80-90
441
how many gills do nautilus have
4
442
what are nautilus
early cephalopods with chambered shells
443
what are included in the subclass coleoidea of cephalopods
squid
cuttlefish
octopus
444
when present, what is the shell of coleoidea cephalopods
internal
445
describe the swimming of coleoidea
good swimmers, by means of jet propulsion through siphon and beating fins
446
how many tentacles do coleoidea have that bear suckers
8-10
447
how many gills do coleoidea have
2
448
what do coleoidea possess for protection
ink sacs
449
what are the only molluscs with a closed circulatory system
cephalopods
450
what do cephalopods show due to a highly developed brain
complex behaviours such as courtship, socialising and memory
451
what are the pigment cells of cephalopods that allow them to change colour
chromatophores
452
what produces the colour changes of chromatophores in cephalopods
the contraction and expansion of the pigment cells controlled by the nervous system
453
how many pairs of arms do squid have
4
454
how many pairs of tentacles do squid have
1 that are retractable
455
describe the fins of squid
always present
| do not merge at rear
456
how many pairs of arms do cuttlefish have
4
457
how many pairs of tentacles to cuttlefish have
1 that are retractable
458
describe the fins of cuttlefish
always present
| merge along the midline or rear
459
what coleoidea do not have shells
octopus
460
how many pairs of arms do octopus have
4
461
describe the fins of octopus
usually no fins present
462
what is torsion
twisting of body parts during larval development in gastropods
463
when does torsion occur
only in the veliger stage in gastropods
464
identify an advantage of torsion for defence
defence against predators in larvae + adults as it allows head to be retracted into shell
465
identify 3 advantages of torsion in aquatic species of gastropods
less silting
better sensory perception
stability of snail, with shell repositioning
466
identify an advantage of torsion in terrestrial species
better ventilation due to anterior positioning
467
identity a disadvantage of torsion in gastropods
fouling of gills or sense organs on head
468
identify 3 evolutionary solutions to torsion
longitudinal slit through shell
asymmetrical cavity
detorsion of 90 degrees
469
what are included In the class Bivalves
muscles
clams
oysters
scallops
470
describe the feature unique to bivalves
two halves, hinged
471
describe the head of bivalves
reduced, often totally absent
472
describe the radula of bivalves
absent
473
why is the radula of bivalves absent
they are filter feeders
474
how do bivalves feed
by bringing water in through incurrent siphon and filtering food particles with large gills
475
what allowed bivalves to colonise other habitats than the sediment surface
siphons and filter feeding
476
identify an invasive bivalve
zebra mussel
477
identify the 3 main classes of molluscs
gastropods
bivalves
cephalopods
478
what are included in the class Scaphopoda
tusk or tooth shells
479
what are Scaphopoda surrounded by that they use to locate and capture food
captacula
480
what is unique to the class monoplacophora
limpet-like single conical shell
481
describe the sexes in monoplacophora
seperate
482
what are included in the class polyplacophora
chitons
483
describe the body shape of chitons
oval
| dorsally flattened
484
describe aplacophora's body feature
without shell
485
identify the 4 main features of a gastropods body plan
torsion
single dorsal shell
distinct head
muscular foot for gliding/swimming
486
identify the 4 main features of a bivalves body plan
2 shells
reduced or absent head
modified gills for filter feeding
sessile lifestyle
487
identify the 3 main features of a cephalopods body plan
reduction or loss of shell
head-foot modified (tentacles/arms)
siphon for jet propulsion
