Which organs are used by flatworms and earthworms for excretion?
Which organs are used by flatworms and earthworms for excretion?
Flatworms lack a circulatory system, so their flame cells excretory system picks up wastes directly from the body tissues. The cells of segmented worms, such as earthworms, produce urea that is excreted through long tubules called nephridia, that work in conjunction with the earthworm’s circulatory.
What is the name of excretory organ in earthworm?
nephridia
What is the excretory system of flatworms?
Flatworms have an excretory system called protonephridia. Protonephridia are made up of many flame cells. The function of these cells is to regulate the osmotic pressure and maintain its ionic balance. So the correct answer is ‘protonephridia’.
Do flatworms have malpighian tubules?
(2) Flatworms have an excretory system that consists of two tubules. Malpighian tubules are convoluted, which increases their surface area, and they are lined with microvilli for reabsorption and maintenance of osmotic balance.
How do flatworms remove waste?
Many invertebrates such as flatworms use a nephridium as their excretory organ. At the end of each blind tubule of the nephridium is a ciliated flame cell. As fluid passes down the tubule, solutes are reabsorbed and returned to the body fluids. Water is reabsorbed and waste is expelled from the insect.
How do flatworms reproduce?
Flatworms are hermaphroditic (having both male and female sex organs) and they typically reproduce both sexually and asexually. The majority of sexual reproduction is through cross-fertilization (where both individuals fertilize each other).
Are flatworms harmful to humans?
Not only are they an invasive species that can cause real environmental damage, but they also are known to carry a parasite called rat lungworm that can cause a form of meningitis in humans. Besides that, this flatworm produces toxic secretions that may trigger an allergic reaction in some people.
How many eggs do flatworms lay?
In all species the adults have complex reproductive systems, capable of producing between 10,000 and 100,000 times as many eggs as a free-living flatworm.
Do flatworms have a stomach?
Do flatworms have a stomach? -Yes7. Describe digestion in flatworms. -They have incomplete digestive systems and use extracellular and intracellular complementary digestion11.
Why must flatworms be flat?
Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end.
Do flatworms have brains?
Flatworms’ bodies are bilaterally symmetrical and they have a defined head and tail region. They have a central nervous system containing a brain and a nerve cord. Clusters of light-sensitive cells on either side of their head make up what are called eyespots.
Do flatworms have eyes?
Planarian flatworms, which often live in dark, watery environments shielded from direct light, don’t have complex eyes like we do. But many do have two lensless, primitive “eyespots” on their heads that can detect the intensity of light.
Why do flatworms not need blood?
There is no need for a special circulatory system as a human has because the flatworm doesn’t breathe with lungs and doesn’t need to transport oxygen around its body. The flatworm simply diffuses oxygen via its skin. This acts in the same way that blood does in that it moves the oxygen around the animal.
How many flatworms are there in the world?
20,000 flatworm
What diseases do flatworms cause?
Cestodes cause life-threatening diseases such as neurocysticercosis and echinococcosis, in which larval tapeworms form cysts inside human tissues (Figure 3B,E). Trematodes such as Clonorchis sinensis and Opisthorchis viverrini are among the few pathogens known to cause cancer.
What are the harmful effects of flatworms in man?
They feed on blood cells and cause a disease called schistosomiasis. The symptoms vary, depending on which parts of the body the worms inhabit, but can include fever, abdominal pain, coughing, diarrhea, and enlargement of the liver and spleen.
What is the meaning of flatworms?
flatworm. [ flăt′wûrm′ ] Any of various parasitic and nonparasitic worms of the phylum Platyhelminthes, characteristically having a soft, flat, bilaterally symmetrical body. Flatworms lack a coelom (body cavity), respiratory system, and circulatory system, but are the most primitive invertebrates to have a brain.
What happens when free-living flatworms are damaged?
Free-living flatworms can reproduce asexually by regeneration. This is a process in which body parts that are missing due to damage or predation can be regrown. A planarian that is cut in half horizontally can grow a new head on the tail end and a new tail on the head end, forming two new organisms.
What do free-living flatworms eat?
Unlike their parasitic cousins in the flatworm group (the tapeworms and flukes), most turbellarians are free-living, and most are carnivores, eating tiny aquatic invertebrates such as rotifers, small crustaceans, and other worms.
Do flatworms have a Coelom?
The features that distinguish flatworms from worms in other phyla include their flat body, their primitive digestive cavity with only one opening, and their lack of a body cavity, or coelom.
Are flatworms Pseudocoelomates?
The flatworms are acoelomate organisms that include free-living and parasitic forms. The nematodes, or roundworms, possess a pseudocoelom and consist of both free-living and parasitic forms.
Do flatworms have teeth?
They inhabit freshwater, and are carnivores (even without teeth) or scavengers. Most are less than a centimeter long. (Click on either of the pictures above for a larger image). Flatworms were once divided into three groups.
Do flatworms shed?
Roundworms are more cylindrical in shape and tapered to a fine point at one end. Similarly, roundworms have a rigid outer covering called a cuticle that they shed repeatedly throughout their lives and as they grow. Flatworms do not have this; their bodies, instead, are covered with cilia, hairlike growths.