Biology 11- 27.2 (tapeworms and roundworms)

class or tapeworms and roundworms

Nematoda

Proglottid

-a reproductive structure which each segments is made of
-youngest ones at head, mature ones at end

what is a proglottid made up of

-Male and female reproductive organs
-Sperm in testes can fertilize eggs in proglottids or other tapeworms
-OR sperm produced by testes can fertilize the same tapeworm

What happens to fertilized eggs?

Burst in hosts intestine OR
after it passed out of body's host in feces

Scolex

the head on tape worms which have suckers and a ring of hooks

digestive system of roundworm

-Long, tube shaped tract
-2 openings
-Food enters through mouth
-Undigested food exits through anus

food requirements of roundworm

-Carnivores
-Some eat algae, fungi, or detritus
-Many live in soil and attach to plant roots and suck cell contents (causes alot of damage)
-Likes specific plants

breathing of roundworms

-Done through body (diffusion)
-No internal transport system
-Diffusion carried nutrients and wastes through body

nervous and muscular system of roundworms

-Ganglia or groups of nerve cells (NOT BRAIN)
-Sense organs
-Nerves run down body - responsible for sending sensory information and controlling movement
Muscles run down body

How roundworms move

Aquatic: contract muscles to move like a snake through water
Soil dwelling: push their way around by wiggling aroung

reproduction of roundworms

-SEXUAL
-Most have seperate male and female, some are hermaphrodites
-Fertilization takes place inside
-2 or 3 hosts to complete life cycle

How ascaris roundworms spread

-Lay eggs there so it goes through feces
-If it gets eaten by another animal the eggs hatch again in the new host

Acoelomate

-No body cavity
-Organs in direct contact with ectoderm
-Mesoderm hold everything together

Pseudocoelomate

-"False/fake cavity"
-Mesoderm only partially lines a fluid filled cavity
-Organs loosely held in place and bot well organized

True coelomate

-True body cavity
-Evolutionary advantage: more room for organs, organ systems and increased surface area for diffusion
-Peritoneum: complete inner lining, allows organs to attach to each other and move around

Nematoda sex organs

-Male: sex organs at rear end, testes produce sperm duct to the seminal vesicles
-Spicules are found at the male's posterior and eject sperm into female
-Female: sex organs at middle of organism
-Ovaries are wrapped around a uterus on each side of worm
-Each uterus connects to a common vagina and opens through a genital pore on the ventral side

testes

the organ responsible for producing sperm

spicule

needle-like mating structure found in males

Phylum which roundworms belong in

Nematoda

Parasitic roundworm

Ascaris

Adult vs young parasitic roundworm

Adults live in intestines so eggs will leave the host in their feces
Young ones will hatch in the small intestine of a NEW host to burrow into the intestine walls and enter blood vessels