Phylum Platyhelminthes : General Characters, Classification and Example , Multiple Choice questions: NEET
🌑Defination
🔴Platyhelminthes are un segmented , Acoelomate , Triploblastic, bilateral symmetrical invertebrate with organ level of organisation.
🌑General features
🔴They are commonly known as flat worm because they have dorso-ventrally flattened body.
🔴These are mostly endoparasites found in animals including human beings.
🔴They are bilaterally symmetrical, triploblastic and acoelomate animals with organ level of organisation.
🔴Hooks and suckers are present as the parasitic adaptation inside the host body.
🔴Some of them absorb nutrients from the host directly through their body surface.
🔴They have some Special cells called flame cells or Protonephredia to help in osmoregulation and excretion.
🔴Sexes are not separate. Fertilisation is internal and development is through many larval stages.
🔴Some members possess high regeneration capacity.
🔴They have a brain with two longitudinal ventral nerve cord.
🔴They Respire through the body surface.
🔴Digestive system is incomplete because a single opening is present which serve as anus or mouth both.
🔴Planaria are well known for its regeneration power. It is capable to form its body part.
🔴They are found in both aquatic ( fresh or salt water) and terrestrial habitat
🔴Their body is unsegmented, bilateral symmetrical and leaf life.
🔴Planaria move by gliding on mucus which is released by ciliated dermis .
🔴Eye spot and Auricle are sense organ in Planaria.
🔴It has a developed Intestine but Respiratory and circulatory system is absent.
🔴Planaria is hermaphrodite and posses both male and female reproductive system in same individual.
🔴Planaria is carnivorous and some species are scavengers.
🟡 Taenia
🔴Taenia is commonly called as Tape Worm.
🔴The body of Tape worm is elongated and divided into many segment called Proglottids.
🔴The tapeworm body is divisible into three distinct parts anterior scolex or head, a short-un segmented neck, and a segmented strobila.
🔴Scolex is present at the anterior end of body. It has four cup-like muscular suckers having radial muscles.
🔴Scolex has Rostellum which has chitinous hooks for the attachment with the intestinal mucosa of host.
🔴Behind the scolex, well developed neck is present which grows continuously and proliferates Proglottids by fission or budding
🔴The neck is followed by the strobila and form main body.
🔴Strobila consists of 800 to 1,000 segments or proglottids arranged in a linear series in a chain-like fashion.
🔴A proglottid is a unit of the body enclosing a complete set of genitalia and surrounding tissue.
🟡 Fasciola
🔴It is commonly called as liver fluke. Fasciola gigantica is longest liver fluke.
🔴Body of fasciola is also flat with come like and contain two type of sucker as oral and ventral sucker.
🔴Alimentary canal of fasciola is incomplete.
🔴It is endoparasite in liver and bile duct of host.
🔴It requires two inter mediate host to complete its life cycle. These hosts are Snail and Fish.
🔴The life cycle include various larval stage like Miracidium, sporocyst, Redia, cercariae and Meta cercariae.
🔴It is hermaphrodite and has male and female sex organ in one individuals.
1. Consider the following sentences and select the number of correct statement.
Comments
Post a Comment