Bio Chapter 25 Section 2
Terms in this set (22)
What phylum do roundworms belong?
Roundworms are pseudocoelomates. Explain.
- False body cavity; Round
- First animal to have digestive tract
- Their gut is more evolved than that of a flatworm which are accelerates. That is why they are flat.
What kind of body cavity do rotifers have?
Where are roundworms found?
Describe some physical features of roundworms.
- Cylindrical (pseudocoelomates)
- Tapered at both ends
- Most are less than 1 mm long
Roundworms species can be what?
Roundworms were the first animals to develop what?
complete digestive tract
Explain how most roundworms move nutrients and gases throughout their bodies.
- No circulatory organs or respiratory organs
- Depend on diffusion to move the nutrients and gasses
- Exchange gasses and escrete metabolic waste through their moist outer body coverings
- More complex forms have excretory ducts that enable them to conserve water for living on land, while others have flame cells.
Describe roundworm movement.
- Muscles that run the length of their bodies
- Causes their bodies to move in a thrashing manner as one muscles contract and the other relaxes.
- These muscles also pull against the outside body wall and other pseuocoelom.
What type of "skeleton' do roundworms have?
Fluid within a closed space that provides rigid support for muscles to work against
Roundworm species have separate sexes. Therefore they reproduce
Examples of roundworms.
Many humans diseases related to parasitic roundworms can be attributed to three things. List them.
- Result of carelessness
- Lack of personal hygiene
- Poor sanitation
- Contracted by eating raw or undercooked pork or pork products or wild game infected with the larvae of Trichinella.
- After ingestion worms mature in one to two days.
- Female worms with fertilized egg will burrow into the intentional walls of the host
- After the eggs hatch the larvae burrow into muscles where they form a cysts causing muscle pain
- This can be prevented by cooking meat properly.
- Common in warm climate when people go barefoot
- When the hookworm comes into contact with skin it cuts its way inside and travels to the bloodstream to the lungs.
- Then to the windpipe where it is coughed up and swallowed.
- Moves into the small intestine where it attacked to the intentional walls and feeds on the blood and other tissue.
- Can be prevented by wearing shoes
What is the most common roundworm that causes human infection?
- ascarid worms
- Eggs found in soil in subtropical and tropical areas
- Enter through the mouth and live in intestines
- It can result when unwashed vegetables form contaminated soil are put in the mouth.
- It can be controlled by carefully washing vegetables and hands.
Filarial Worms in Humans
- Called elephantiasis
- Filarial worms- roundworm parasites that live in tropical areas.
- Intermediate host: mosquitos
- When the mosquito sucks blood from a person who is infected with the roundworm the embryos are passed into the insects bloodstream. The embryo then grown into a larvae. They are passed to another person when the mosquito bites again. Adult worms accumulate in the lymphatic system and and obstruct the flow of lymph. This fluid builds up in tissue causing legs and other body regions to enlarge.
- Controlling mosquitoes and using mosquito netting at night can aid and preventing this disease.
Filarial Worms in Cats and Dogs
- Heart worm
- Transmitted to dogs and cats through mosquito bites
- Once in the bloodstream the worms travel to the heart and block the flow of blood.
- Regular doses of oral medication prevent heartwood in dogs and cats.
Nematodes in Plants
- Species of roundworm the cause diseases in plants
- Can infect and kill pine trees, soybean crops and food plants such as tomatoes.
- When they infect plant roots they damage the plant.
- Some can be harmful an others beneficial to plants
- Some species are used to control the spread of cabbage worm caterpillars, Japanese battle grubs and many other pests of plants.
- Spraying a solution of nematodes and water on areas that are infested with crop pests is most effective when the targeted pest is at the stage in its life when it lives in the soil.
- They can also be used to control pests of human and animals.
- They eat flea larvae
- Most common nematode parasite in humans in the US.
- The highly incident of infection occurs in children.
- At night the female living in the intestine more out of the anus and lay eggs on nearby skin. When the skin is scratched the eggs are transferred to hands and them to any surface that is touched. They can survive for up to two weeks on surfaces and are ready to hatch if another person injects them.
- The can spread quickly among children who put toys and other objects in their mouthes.