Chapter 18: Superphylum Ecdysozoans, Phylum: Nematoda - Roundworms Flashcards
Many prefer what name for this phylum?
-Nemata
They are found in virtually all habitats in all biomes. The top soil may contain ____ per acre. Nematode parasites exist in nearly all ___ and ___ species.
- billions
- animal
- plant
Free-living nematodes feed on what four things?
- bacteria, yeast, fungal hyphae and algae
Predatory nematodes feed on what four things?
- rotifers, tardigrades, small annelids and other nematodes
They are important as food for what four things?
- insects, mites, larvae and fungi
Those in phylum Nematoda have a ____ shape and a ____ cuticle.
- cylindrical, nonliving
One of the characteristics used for placing the nematodes in the superhylum is that the cuticle is shed during _____ stages.
- juvenile growth
They lack ___ or ___ except for one species.
- motile cilia or flagella
There is only ____ present in the body wall which contribute to the thrashing movement seen in this phylum.
- longitudinal muscles
They express eutely which means what?
- they have a fixed number of somatic cells once maturity is met, further growth is only seen via cell enlargement not division.
They lack _______ (hint: aid in excretion). The pharynx is ___. The outer, thick, noncellular cuticle is secreted by underlying ____.
- protonephridia
- muscular
- hypodermis
The hypodermic is ____ with nuclei located in four hypo dermal cords projecting inward.
- synctyial ( mass of multinucleated cytoplasm not divided into other individual cells)
They possess dorsal and ventral ____ cords with nerves. The lateral cords have ____ canals.
- hypodermal
- excretory
The cuticle has layers of crisscrossing ___, providing elasticity but restricting expansion.
- collagen
The longitudinal muscles lie beneath the ____. What is absent?
- cuticle
L> circular muscles
The longitudinal muscles run in __ bands, marked off by hypodermal cords. Each muscle has a ____ fibrillar portion and a ____ sarcoplasmic portion. The sarcoplasmic cell body extends into the ___ and stores ____.
- four
- contractile
- noncontractile
- pseudocoel , glycogen
Unlike in other animals, the cell body process or muscle arm extends to the ____ or _____.
ventral, dorsal nerve
Compressing and stretching of the ____ eturns the body to resting position when muscles relax.
- cuticle
Digestion:
The alimentary canal consists of the ___, ___, ___,___, and ___.
- mouth, pharynx, non muscular intestine, short rectum and anus
The pharynx does what?
- sucks food in
The intestinal wall is __ thick. The food moves ___ as new food enters and the body moves.
-one cell, back
Defecation occurs from opening the ___ and allowing ______ pressure to expel waste.
- anal
- pseudocoelomic
Some parasitic adults have an _____ metabolism without the _____ and ____.
- anaerobic
- krebs cycle
- cytochrome system (electron transport)
Free-living nematodes and free-living stages of parasitic nematodes utilize both ____ and ___.
- krebs cycle
- cytochrome system
There is a ring of ___ and ____ around the pharynx leading to the dorsal and ventral nerve cords.
- nerve tissue
- ganglia
Most are _____ with males ____ than females.
- dioecious
- smaller
Fertilization occurs _____. (hint: location)
- internally
Eggs are stored in the ___ until deposited.
- uterus
The ____ is shed between each of the four juvenile stages.
- cuticle
Some of the parasitic nematodes are parasites to ___. Most tend to be ___. (location globally)
- humans
- tropical
Ascaris lumbricoides ( parasitic round worm) :
-Occurs in up to _% of people in some areas of ___.
-A,meglaocephala is found where in horses?
- A. suum is found where in pigs?
- A female Ascaris may lay ___ eggs a day which pass out in the host’s __.
L> Embryos develop to juveniles in ___.
- 25%, Southeastern US
- intestines
- intestines
- 200,000
- 2 weeks
What is one of the most common parasite found in humans estimated about 64% of the population in southern US and over 1 billion people world wide.
- A. lumbricoides
Visible eggs remain after sings of decal matter have ___.
The eggs can survive a ____ period in soil
- disappeared
- long
Ascaris Infection process:
- The host swallows ______, juveniles arch and burrow through the ____.
- Carried through the ___ to the ___, they break into ___ and are carried up to trachea.
- Coughed up and swallowed , they ___ in the ___ after two months.
- They feed on ___ contents and may block or perforate the ___.
- Infection rates tend to be higher in ____ and ____. Due to what?
-embryonated eggs, intestinal wall
- heart, lungs, alveoli
- mature, small intestine
- intestinal, intestines
- children, males
L> Toys, unwashed vegetables, soiled fingers
Hookworms :
-Anterior end of these small worms has a ___ ?
- The most common hookworm is?
- The sexes are separate or not?
- Large ___ in mouth cut into intestinal mucosa and suck host’s __.
- They pump through more blood than they ___. Heavy infection can cause what?
-Eggs will pass out in feces and juveniles hatch in
__.
- If human skin comes into contact with soil, infective juveniles burrow through __ to __.
- They tan travel in the blood to the ___, ___ to be swallowed and mature in the __.
- hook like curve
- Necator americanus
- separate
- plates, blood
- digest, anemia
- soil
- skin, blood
- lungs, coughed up, intestine
Trichina Worm :
Trichinella spiralis causes a potentially lethal what?
- trichinosis
Trichina Worm:
Cycle:
-Adult worms burrow into ____ and females ____ produce juvenile worms. -Juveniles penetrate ___ and circulate throughout the body to all ___ and ___. -Penetrate _____, redirecting gene expression of the ___.
- intestinal mucosa, directly - blood vessels, tissues and spaces
- skeletal muscle cells, musculature
Trichina Worm:
When poorly cooked meat containing encysted juveniles is eaten, worms are ___ and mature in the ___.
-liberated - intestine
Trichina Worm:
The infect ___, __,___,___, and __.
- humans, hogs, rats, cats and dogs
Trichina Worm:
Hogs become infected eating uncooked scraps of infected __ or __.
- meat, rats
Trichina Worm:
Four other sibling species with variable distribution, freezing resistance etc Heavy infections can cause __.
- death
Trichina Worm:
Juveniles cause redirection of gene expression in host cell and it loses its ____ and becomes a ___ that nourishes the worm.
- striations, nurse cell
Pinworms:
They are the ___ parasite in the US but cause ___ disease.
- most common helminthic, little
Pinworms:
- Adults live in the ___ and __.
- large intestine, cecum
Pinworms:
- Females migrate to the ___ region at ___ and lay eggs causing itching.
- anal, night
Pinworms:
-Scratching the _____ contaminates hands and bedclothes.
- anal region
Pinworms:
- Eggs develop ___ and become ___ within six hours at body temperature.
- rapidly, infective
Pinworms:
-When swallowed, the eggs hatch in the ___ and mature in the ___.
- duodenum
- large intestine
Pinworms:
-Members of this order have ___ males from ___ eggs. -Females are ___ and come from _____eggs.
- haploid, unfertilized - diploid, fertilized ( haplodiploidy )
Fliarial worms:
-There are __ species of filarial nematodes that infect humans and some cause serious diseases.
-8
Fliarial worms:
- Wucheria bancrofti and Brugia malayi live in the ____.
lymphatic system
Fliarial Worms: Wucheria bancrofti and Brugia malayi:
- They cause ____ and ___ of the lymphatic’s vessels.
- Females release __ young, tiny ___, into blood and lymph.
- inflammation, blockage - live, microfilariae
Fliarial Worms: Wucheria bancrofti and Brugia malayi:
- Mosquitoes ingest the microfilariae when they ___. The worms develop to ___ stage and move into the mosquito bite wound when it feeds.
- feed, infective
Fliarial Worms: Wucheria bancrofti and Brugia malayi:
-Elephantiasis is caused by ____ exposure. Describe the symptoms?
- repeated
- swelling and growth of connective tissue causes enormous swelling of body parts.
Fliarial Worms:
- onchocerciasis or _____ is carried by ___ and infects 37 million people in tropics.
- Dirofilaria immitis or _____ is carried by ____ and is the most common US filarial worm.
- river blindness, black flies - Dog heartowrm, mosquitos
List in order the life cycle of a Guinea worm!
- 1st stage larvae + emerging female worm
- Copepod
- 3rd stage larvae L>drank in water via host - Released larvae in host
Adaptive diversification :
- Nematodes show the most impressive adaptation. They are found in ___ habitat available to most animals.
- The body structure is ___ enough to allow adaptation - Life cycle ranges from __to___.
- Have been known to survive in ____ conditions
- almost every
- plastic
- simple to complex -suboptimal
