Week 5 Flashcards
(124 cards)
1
Q
molting ecdysis
A
flexible yet tough cuticle requires molting in order to grow, but also provides protection while being thinner and lighter than mineral skeleton
2
Q
how times does annelids molt before maturing
A
4 times
3
Q
what does molting often include in nematoda
A
metamorphosis
4
Q
what does metamorphosis allow for nematoda to have
A
separate body plans in juveniles and adults
5
Q
are nematoda tripoblastic bilateria
A
yes
6
Q
what is pseudocoel a remnant of
A
blastocoel
7
Q
pseudocoelmates
a body cavity (psedocoel or coelom)
A
space for development of organ systems
simple means of circulating materials around the body
a hydrostatic skelton
8
Q
hydrostatic skeleton
A
fluid filled cavity is a more rigid structure for muscles to act against than the tissue filled body of an acoelomate
9
Q
do most pseudocoelmates have a complete digestive tract
A
yes
10
Q
Phylum Nematoda characteristics
A
roundworms 25,000 species marine, freshwater, wet soils, inside plants, and animals unsegmented, pseudocoelmate, protosome, tribloblastic, bilaterians vermirorm body posses a complete gut cuticle that molts ubiquitous and abundant
11
Q
vermifrom
A
worm like
12
Q
do nematodes have a complete, one-way digestive tract
A
yes
13
Q
what percentage of Phylum Nematoda is parastic
A
50%
14
Q
is Phylum Nematoda an important group of parasites
A
yes
15
Q
Phylum Nematoda form & functions
A
collagenous cuticles, secreted by hypodermis
4 juvenile stages, serparated by molts
mesoderm develops into muscle bundles around outside wall of body (longitudinal only, no circular)
degestive tract
dorsal and ventral nerve cords
nerve cords connected to circular ganglion (simple brain) around pharynx
16
Q
digestive tract of Phylum Nematode
A
mouth > pharynx > intestine > rectum > anus
17
Q
where does mesoderm develop into muscles bundles
A
around outside wall of body
18
Q
how do muscles work in Phylum Nematoda
A
muscles sends out processes to dorsal and ventral nerves cords
19
Q
how are muscles connected in Phylum Nematoda
A
connected not by nerves but by evaginations of muscles themselves
20
Q
where do nerve cord connect in Phylum Nematoda
A
to circular ganglion (simple brain) around pharynx
21
Q
Phylum Nematoda response to stimuli
A
fluid in pseudocoelom under high pressure
inelastic cuticle
these form a hydrostatic skeleton
only longitudinal muscles
contract muscles on one half of body then the other
can only bend in dorsal or ventral direction
22
Q
what causes roundness in Phylum Nematoda
A
high pressure, cuticle contains pressure, can use pressure as a hydrostatic skeleton
23
Q
can Phylum Nematoda move without a substrate
A
no
24
Q
Phylum Nematoda energy transformation
A
pharynx opens into complete digestive tract, unidirectional processing of food
first animal we’ve really looked at that has a true one way digestive system
pharynx needed to pump food into digestive system because of that high internal pressure
anus opens using dilator muscles, pressure pushes contents out
may have “teeth” or stylet to puncture cells, depending on diet
25
Phylum Nematoda reproduction
```
sexes vary depending on species
most are dioceious
some species have 3 or more sexes
copulatory spicules in males
ameboid sperm
```
26
ameboid sperm
move via pseudopods instead of flagellum
27
are spicules a true intromittent organ
no they do not conduct sperm
28
nematode who's who in human diseases
```
ascaris
pinworms
hookworms
trichina worms
filarial worms
guinea worms
```
29
Ascaris lumbricoides
giant round worms
30
how many people are infect with Ascaris lumbricoides
807 to 1.2 billon people
31
how many eggs can a single female Ascaris lumbricoides reproduce in a day
200,000 eggs
32
how is Ascaris lumbricoides contracted
eating raw veggies contaminated with shelled juveniles often passes infection,
33
Enterobius vermicules
pinworms "seatworms"
| relatively small, females with pointed posterior end, males curled
34
what is the most common nematode parasite in North America
Enterobious vermicularis
20% of children
10% of adults
35
what does "seatworm" refer to
main symptom of pinworm infection
| itchy butt
36
how does Enterobius vermicules develop
males develop from unfertilized eggs,
| females develop from fertilized eggs
37
Trichina worm
| Trichinella spp
can infect humans through cysts in undercooked pork
one of largest known intracellular parasties
transforms host muscle cells into nurse cells
38
what causes trichinosis
encysted Trichinella
| juveniles change host cell gene expression, become nurse cells that nourish worm
39
what can Trichina worms infect
wide variety of mammals
| humans, pigs, rats, cats, dogs,
40
what can a heavy infection of Trichina worms cause
possible neurological symptoms, heart disease, and death
41
filarial worms
live in lymph passages and block flow of lymph
| elephantiasis
42
elephantiasis
excessive growth of connective tissue, swelling
43
how many species of flarial worms infect humans
8
44
filarial worm: Dirofilaria immitis
carried by mosquitos
| found in mammals(canids, felids, humans)
45
what is the prevalence of Dirofilaria immitis in dogs
may be as high as 20%
46
what is the most common filarial worm in the US
Dirofilaria immitis
47
guinea worms: Dracunculus medinensis
up to 1 meter long, 2 mm in diameter
unusual live cycle
juveniles escape host via open blister, exposing the adult female as well
48
how do you contract guinea worm: Dracunculus medinensis
by drinking stagnant water with copepods infected with larvae
49
copepods
tiny crustaceans
50
what does the blister of Dracunculus medinensis cause
intense burning sensation, called "fiery serpent"
51
how so you remove Dracunculus medinensis
soaking in water to coax out worm and slowly pulling out
stop if resistance is met to avoid breaking worm
make take several days to fully extract
often kept wrapped around a stick to maintain tension
52
what are nematodes important for
ecosystem function
| especially carbon and nitrogen cycle
53
metamerism
serial repetition of similar body segments, along longitudinal axis (metamere or somites)
seen in protostomes and deuterostomes
annelids, arthoprods, chordaes, segment- specific genes involved
54
how are different body parts of an animal produced
activation of different combinations of genes in different segments
55
do all cells within an organism have the same DNA
yes
56
spicuncula
peanut worms, have lost segmentation, live in burrows
57
Phylum Annelida characteristics
segmented
vermiform
protostome bilateral coelomates
use a hydraulic skeleton and setae (chaetae) for locomotion
most possess a complete digestive tract, filtration nephridia, and a closed circulatory system
58
setae
bristles that help anchor things like earthworms in the soil and can help marine forms swim
lost in some groups
59
what do annelids have on nematodes
true coelomic cavity
complex circulatory system with muscular vessels and aortic arches
specialization of head region
60
metamerism
serial repetition of body parts
61
coelomic cavity of annelids
expanded, divided by septa, allows for more control of body and hydrostatic skeleton
62
circulatory system in annelids
```
closed circulatory system
main dorsal and ventral vessels
aortic arches
each segment has vessels that branch from ventral vessels into organs and muscles
blood collects back into dorsal vessels
```
63
aortic arches
function like heart, pump blood
64
Phylum Annelids body form
well developed coelom, fluid functions as hydrostatic skeleton, helps with nutrient and oxygen transport
peritoneum lines segment, including septa
have chitinous setae, some with parapodia
65
peritoneum
layer of mesodermal epithelium
66
parapodia
paddle like appendages
| chitinous setae on parapodia
67
what divides segments
septa
68
coelom of annelids
coelomic fluid helps with nutrient and oxygen transport, and also functions as a hydrostatic skeleton
69
what does each segment of an annelid have
2 coelomic compartments, separated by mesentaries (dorsal and ventral) which support internal structures
70
Phylum Annelid sementation
segmentation into metameres
| repeated nervous system structures for coordination
71
excretory system in Phylum Annelid
each segment contains a pair of nephridia
portion of the tubule that pierces the septum has a ciliated funnel on it
cilia beat and move fluid through into the next segment, then out of the excretory opening
niphridia selectivley uptake salts, glucose, and water
72
nephridiopore
excretory opening
73
what is so great about segmentation/metamerism
development of much greater complexity in structure and function possible
increased efficiency burrowing
independent and separate movements by different segments
fine control of movements= more sophisticated nervous system
built in redundancy- if one segment fails, others can still function
74
Annelid diversity
22,000 species
marine, freshwater, moist terrestrail
traditionally divided into three group: polychaetes, oligochaetes, leeches
75
polychaetes
mostly marine, make up most of the annelids, errant and sedentary forms
76
sedentaria
includes the earthworms and leeches, despite the fact that many move around
77
echiura
recently moved to his position on tree, used to be sister taxa to annelids
not segmented, but had a segmented ancestor and lost segmentation
78
clitellata
have clitellum
79
clitellum
used in reproduction
80
polychaete
have a lot of setae, generally have parapodia
saltwater only
make up 2/3rds of annelids
81
errantia
motile polychaetes
82
sedentaria
sedentary polychaetes, lives in tubes or burrows
83
lugworm
lives in burrow, eats sand to get food
84
oligochaete
have fewer bristle/setae than see in the polychaetes and have lost parapodia,
freshwater and moist terrestrial
85
tubifex
live head-down in tubes, often found in sewer lines
86
stylaria
long, pointed proboscis
87
do leeches have a fixed number of segments
yes,
88
leech characteristics
most freshwater, some marine or terrestrail
have suckers
many with y- shaped, cutting jaw
89
polychaetes
errant and sedentary forms
over 10,000 described species
mostly marine
90
polychaetes body form
head well developed, particularly in the errant form
prostomium-
persitomium-
parapodia-
91
prostomium
in front of mouth, basically the head, doesn't contain mouth, has sensory structures,
92
persitomium
first body segment, behind the head, contains the mouth,
93
parapodia
paddle like appendages that bear the setae
94
errant polychaetes
free living
jaws
scavengers or predators
95
sedentary polychaetes
tubes or burrows
| filter or deposit feeders
96
filter feeders
specialized segments that look like fans and move water,
| generate mucous to capture food particles and transport it to the mouth
97
deposit feeders
tentacles that extend from burrow to gather particles or suck water and sediment into burrow to get food particles out of sand
98
olychaete reproduction
dioecious
most sexual reproduction, some asexual
external fertilization
no distinct gonads, masses of developing gametes develop as swelling of peritoneum in some segments
99
how do polychaetes gametes develop in some
gametes develop in a chain of segments called an epitoke
100
what kind of larvae do polychaetes have
trochophore larvae
101
atoke
stays in sediment (can create new epitoke for next spwaning period/season)
102
how do polychaetes know when to swarm
by lunar phase, pheromones, water temperature, or combination
103
what is synchronous spawning good for
increasing chance of fertilzation in broadcast spwaners
104
why is synchronous spawning bad
attracts a lot of things trying to eat
105
oligochaetes
few setae
lack parapodia
>3,000 species
freshwater, terrrestrail, a few marine or parasitic
106
what is setae used for during locomotion
used to anchor self
107
oligochaetes response to stimulus
cephalization
| in some species the prostomium is prehensile and can be used to drag things like grass and leaves into their burrow
108
cephalization
paired ganglia make up the brain, connect to ventral nerve cord which has paired ganglia in each segment for coordination, generally more adapted for a burrowing lifestyle (some non-burrowing forms have tentacles on prostomium)
109
oligochaete reproduction
```
monoecious
clitellum
true gonads
mostly sexual reproduction
direct development (no larval stage)
```
110
oligochaete sexual reproduction
bring ventral surface together, mucocus secreted by clitellum and setae hold them together
sperm is discharged form genital opening and moves through seminal grooves on outside of body to the seminal receptacle of the other individual, after sperm exchanged, worms part way
111
what do oligochaete do after sexual reproduction
each worm produces a mucous band around clitellum, then a tougher band around that to form a cocoon with mucous inside
cocoon slide forward over head
as it passes oviduct it picks up eggs, and as it passes seminal receptacle picks up sperm from other worm
112
where does embryonic development take place
in cocoon until young worms hatch
| have direct development no larval stage because they are on land
113
hirudinea
```
leeches
700 species
mostly freshwater
no setae (few exceptions)
lack septa between segments
anterior and posterior suckers
bloodsuckers secrete anticoagulant (hirudin), lack digestive enzymes
```
114
what takes up most of the inside of leeches
connective tissue and muscle
115
do leeches burrow
no
116
what is the anterior suckers for in leeches
feeding
117
what is the posterior suckers for in leeches
for attachment and leverage
118
anticoagulant
hirudin
119
can leeches secrete anesthetic
yes,
120
what do leeches rely on for digestion
bacteria
121
leeches in medicine
| problem- microsurgical procedures that restore arteries, but not delicate veins
```
solution: leeches
vasodilation
anticoagulant
anethetic
cheap
cool
```
122
leech reproduction
```
monoecious
true gonads
sexual reproduction
internal fertilization
direct development
often a higher level of parental investment
```
123
when is clitellum present in leeches
only during breeding season, secretes cocoon for eggs and sperm, development occurs inside cocoon
124
where can leech cocoon be attached
to submerges objects or buried, some keep cocoon attached to ventral surface of parent for protection
