9 public questions tagged with this topic.
Echinoderms possess a unique water vascular system, which aids in locomotion, food capture, and respiration.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Mollusca and Echinodermata
Mollusks have an open circulatory system, except for cephalopods like squids and octopuses, which have a closed circulatory system.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Mollusca and Echinodermata
Poriferans have a unique water canal system, which helps in food gathering, respiration, and excretion.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Arthropoda
Echinoderms, such as starfish, lack a specialized excretory system and rely on diffusion for waste removal.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Aschelminthes and Annelida
Birds lack a diaphragm; instead, they use air sacs for respiration.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Phylum Ctenophora and Platyhelminthes
Mollusks have an open circulatory system, but cephalopods (e.g., squids and octopuses) have a closed circulatory system.
Ref: NCERT Class 11 Biology Chapter 4: Animal Kingdom Basis of Classification - Symmetry Coelom Segmentation
True fishes or Pisces display circulatory architecture comprising two cardiac chambers, single thin-walled atrium receiving deoxygenated blood from sinus venosus and single thick-walled ventricle pumping to ventral aorta and gills via bulbus arteriosus. Oxygenated blood proceeds via dorsal aorta to systemic tissues in single circuit, no pulmonary bypass, resulting in low systemic blood pressure. This two-chambered heart contrasts with three-chambered design in amphibians and reptiles with double circulation partially mixing, and four-chambered separation in birds, mammals and crocodilians enabling high-pressure systemic supply essential for endothermy.
Ref: Campbell Biology, 12th ed., Chapter 42: Fish Circulation; NCERT Class 11, Chapter 4, Pisces Heart
Class Agnatha includes extant jawless craniates, representing earliest diverging vertebrate lineage lacking jaws derived from mandibular branchial arch, also lacking true paired appendages, dentine and bone in many forms. Characteristics include persistent notochord surrounded by arcualia, single median nostril in lampreys, multiple gill pouches opening separately, keratinized tooth-like structures and cartilaginous skeleton. Modern examples are Petromyzon lamprey and Myxine hagfish. Chondrichthyes, Osteichthyes and extinct Placodermi are jawed gnathostomes. Agnatha thus serves as stem group crucial for understanding evolution of jaws, paired fins and vertebral mineralization in chordate phylogeny.
Ref: NCERT Class 11 Biology, Chapter 4: Cyclostomata Agnatha; Campbell Biology, 12th ed., Chapter 34
Kingdom Plantae is the highest taxonomic group dedicated exclusively to plants. It comprises all autotrophic, eukaryotic organisms with cellulosic cell walls, grouping together all the various plant Divisions. This separates them fundamentally and at the highest taxonomic level from the heterotrophic organisms grouped in Kingdom Animalia.
Ref: NCERT Class 11 Biology
