16 public questions tagged with this topic.
Annelids exhibit metameric segmentation, meaning their body is divided into repetitive segments. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Biology - Zoology portion covering relevant system and function.
Nephridia are the excretory structures in annelids like earthworms, responsible for the removal of nitrogenous waste.
Ref: NCERT Class 11 Biology Chapter 16: Excretory Products and their Elimination Urine Formation - Glomerular Filtration
Annelids move by contracting longitudinal and circular muscles along with the help of setae (bristles) for traction.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Arthropoda
Parapodia are lateral appendages in Nereis that help in swimming and locomotion.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Aschelminthes and Annelida
Earthworms belong to phylum Annelida and exhibit true segmentation but do not have jointed appendages like arthropods.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Aschelminthes and Annelida
The clitellum in annelids secretes mucus that aids in cocoon formation during reproduction.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Aschelminthes and Annelida
Annelids do not have Malpighian tubules; they use nephridia for excretion.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Basis of Classification - Symmetry Coelom Segmentation
Annelids exhibit metameric segmentation, meaning their body is divided into repetitive segments.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Basis of Classification - Symmetry Coelom Segmentation
Both annelids and arthropods exhibit metameric segmentation, where the body is divided into repetitive segments.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Basis of Classification - Symmetry Coelom Segmentation
Trochophore larva is free-swimming ciliated planktonic prototroch larva characterized by equatorial ciliary band prototroch derived from trochoblasts, apical sensory tuft, ventral stomodaeum, pair protonephridia, serving as developmental link between Annelida and Mollusca. Occurs in primitive marine polychaete annelids and basal molluscan classes including Polyplacophora Bivalvia as early stage preceding veliger. In annelids develops into metatrochophore with added segments, in molluscs metamorphoses into veliger adding foot mantle shell. Presence indicates shared spiralian ancestry within Lophotrochozoa spiral cleavage emphasizing conserved larval morphology and evolutionary kinship between segmented worms and conchiferan molluscs through developmental studies.
Ref: Campbell Biology, 12th ed., Chapter 33: Trochophore larva Annelida Mollusca; NCERT
Leeches represent highly specialized derived annelids classified under Class Hirudinea distinguished by dorsoventrally flattened body, fixed number 32 internal segments externally subdivided by annulations, complete loss setae and septa except anterior, presence anterior sucker surrounding mouth and large posterior sucker for attachment and inchworm locomotion, clitellum only during breeding secreting cocoon, hermaphroditic with direct development, predominantly freshwater but also marine terrestrial, many sanguivorous ectoparasites feeding on vertebrate blood. Coelom reduced to sinuses filled with botryoidal tissue, vascular system modified into haemocoelomic sinuses. Hirudo medicinalis example historically employed for anticoagulant hirudin secretion.
Ref: NCERT Class 11 Biology, Chapter 4: Hirudinea leeches; Campbell Biology, Annelida
Earthworms belong to Class Oligochaeta within Phylum Annelida meaning few bristles, characterized by reduced setae per segment typically four pairs, lack parapodia and head appendages, absence eyes, hermaphroditic system with clitellum secreting cocoon, primarily terrestrial and freshwater habitats with direct development lacking free larval stage. Exemplar Lumbricus terrestris shows over 100 metameric segments, closed circulation with five aortic arches as hearts, metanephridial excretion, cutaneous respiration, typhlosole. Oligochaeta contrasts markedly with Polychaeta bearing numerous chaetae parapodia separate sexes for marine life, and Hirudinea leeches lacking setae possessing suckers and fixed segment number throughout body.
Ref: NCERT Class 11 Biology, Chapter 4: Oligochaeta earthworms; Campbell Biology, Annelida
