🇮🇳
NEET Master Hub Visit Hub ➔
🇺🇸
USA Grade 10 View Page ➔

Phylum Platyhelminthes : General Characters, Classification and Example , Multiple Choice questions: NEET


Definition 

  • Platyhelminthes are unsegmented , 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 with body sac plan, 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 Protonephridia to help in osmoregulation and excretion. 
  • Sexes are not separate. Fertilisation is internal and development is through many larval stages. 


To watch detail video lecture on 
Platyhelminthes here 



  • 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.

Examples of Platyhelminthes  

Planaria 

  • 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.

Read also notes and MCQs of Phylum Coelenterata 

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.

 Read also Notes and MCQs on Phylum Porifera 

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. Hence it is digenetic .
  • 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.

Are you looking for a structured Study Guide and Unit Test on this topic? Check out our Grade 10 Study Guide here


Comparison table for the Flat worms .

Feature

Planaria (Dugesia)

Liver Fluke (Fasciola)

Tapeworm (Taenia)

Habitat

Free-living (Freshwater)

Endoparasite (Liver/Bile duct)

Endoparasite (Intestine)

Host

No Host (Free)

Digenetic (Snail & Sheep)

Digenetic (Pig & Human)

Digestion

Gastrovascular Cavity present

Present but incomplete

Absent (Absorbs nutrients)

Specialty

High Regeneration Power

Suckers for attachment

Scolex with Hooks & Suckers



 1. Consider the following sentences and select the number of correct statement.

A.Members of Platyhelminthes have  dorso-ventrally flattened body.
B. Members of platyhelminthes are commonly called as Round worm .
C. They are Mostly endoparasite in animals including Human.
D. Animals are Bilateral Symmetrical and pseudocoelomate.
A. One.         B. Two
C. Three.      D. Four  
Answer : B  

2. Which of the following feature is  present in members of Platyhelminthes.

A. Organ level of organisation and Triploblastic
B. Pseudocoelomate and Radial symmetry
C. organ system level of organisation and Diploblastic 
D. Acoelomate and Radial symmetry
Answer : A  

3.Which of the following is not a characteristics of   present of Flat worm.
A. Acoelomate 
B.Organ system level of organisation.
C. Bilateral symmetrical
D. Triploblastic 
Answer : B 

4.Which of the following is not a characteristics of  present of Flat worm.
A. Acoelomate 
B.Organ system level of organisation.
C. Bilateral symmetrical
D. Triploblastic 
Answer : B 

5.Which of the followings special cell or structure  is  involved in  Excretion and osmoregulation of Flat worm.
A. Nephredia 
B. Flame cells 
C. Proto nephredia 
D.Flame cells and Protonepheredia both . 
Answer : D 

6.Which of the following Flat worm has high generation capacity.
A. Fasciola.  B. Taenia
C.Planaria D. All of the above
Answer : C 

7. Consider the following statement and select the correct code:
1.  In Flatworm , hooks and suckers are present as the parasitic adaptation inside the host body.
2. Some of th flatworm  absorb nutrients from the host directly through their body surface. 
A. Only 1   
B. Only 2
C. Neither 1 nor 2 
D. Both 1 and 2 
Answer : D 

8.  In Flatworm, Development is indirect with 
A. One larval stage
B. Two larval stage
C. Three larval stage
D. Many larval stage 
Answer : D  

9. Consider the following condition that were appeared  first in flat worms and select the correct code;
1. Triploblastic 
2. Organ level of organisation 
3. Bilateral symmetry 
A. 1  2 and 3
B. 2 and 3
C. 3 only 
D. 1 only 
Answer : A  

10. Identify the following diagram.
A. Fasciola
B. Lumbricus
C. Ancyclostoma 
D. Planaria
Answer : A  

11. Which one of following is a Tape worm.
A. Fasciola
B. Planaria
C. Ascaris
D. None of the above 
Answer : D  

12. Fasciola complete its life cycle with which of the following two intermediate host.
A. Fish and copepods
B. Mosquito and sheep 
C. Snail and fish
D. Snail and Sheep 
Answer : C  

13. Which one of the following is a human liver fluke.
A. Fasciola 
B. Taenia
C. Planaria
D. Ascaris
Answer : A  

14. Which one of following features  is  not present in  all members of the flat worm.
A. Excretion by flame cells
B. Acoelomate 
C. Bilateral symmetrical 
D. Absorption of food through body surface
Answer : D  

🚀 Agla Kadam (Next Steps)

Biology ki taiyari ko aur mazboot banayein!

Doston ke saath **Share** karein aur comment mein batayein agla topic kya ho!

Comments

Post a Comment