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TU B.Sc. First Year Syllabus: Zoology
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TU B.Sc. First Year Zoology (Zool. 101) — Complete Syllabus Overview

Zoology is one of the major subjects offered under the Four-Year Bachelor of Science (B.Sc.) programme of Tribhuvan University’s Institute of Science and Technology (IoST), Kirtipur, Kathmandu. The First Year Zoology course, officially titled Non-Chordata and Protochordata (Course No. B.Sc. Zool. 101), is a 100-mark theory paper accompanied by a 50-mark practical paper (Zool. 102), making the combined First Year Zoology assessment worth 150 marks. The course totals 150 lecture hours organized across 6 major units.

The course introduces students to the full diversity of the animal kingdom below the vertebrates — from the simplest unicellular protozoans through all major invertebrate phyla (Porifera, Cnidaria, Platyhelminthes, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata) — and concludes with the Protochordata (Hemichordata, Urochordata, Cephalochordata), the invertebrate-chordate bridge group. It is the foundational course for all four years of the B.Sc. Zoology programme and directly relevant to the MECEE-BL medical entrance examination and careers in wildlife, conservation, fisheries, parasitology, and biological research.

Subject Information at a Glance

  • Course Title: Non-Chordata and Protochordata
  • Course No.: B.Sc. Zool. 101 (Theory) | B.Sc. Zool. 102 (Practical)
  • Year: First Year — Four Year B.Sc. Programme
  • Full Marks: 100 (Theory) + 50 (Practical) = 150 total
  • Pass Marks: 35 (Theory) | 20 (Practical) — both must be passed separately
  • Total Lecture Hours: 150 (Theory) | 180 practical periods (Practical)
  • Examination: Annual (end-of-year exam conducted by IoST, TU)
  • Conducting Institution: Institute of Science and Technology (IoST), Tribhuvan University; Central Department of Zoology (CDZ), Kirtipur
  • Curriculum Version: Revised Course of Study 2073 BS (2016)
  • Eligibility: Passed +2 Science (Biological Group) or equivalent with minimum C grade in all subjects

Why Zoology?

Zoology — the scientific study of animals — is one of the broadest and most foundational disciplines in biological science. From the microscopic protozoan parasites that cause malaria and leishmaniasis, to the enormous biodiversity of Nepal’s invertebrate and vertebrate fauna, zoology underpins our understanding of animal form, function, evolution, behavior, ecology, and physiology. In a country like Nepal — one of the world’s 25 biodiversity hotspots, with extraordinary faunal richness spanning five ecological zones from the Terai to the high Himalayas — zoological expertise is directly relevant to national priorities in conservation, wildlife management, disease surveillance, fisheries, agriculture, and environmental impact assessment.

The TU B.Sc. Zoology programme is specifically designed to build from foundational animal diversity in First Year (non-chordates and protochordates), through vertebrate diversity and comparative anatomy in Second Year, to advanced topics in cell biology, genetics, ecology, entomology, parasitology, and fisheries in Third and Fourth Years. Graduates contribute across a range of sectors: government wildlife and conservation agencies, fisheries development, medical and veterinary parasitology, zoological research institutions, environmental consulting, and academic teaching.

Zool. 101 Theory Syllabus — Unit-wise Detail

Unit 1: Introduction to the Animal Kingdom (15 teaching hours)

  • Scope, history and importance of zoology: major branches — invertebrate zoology, vertebrate zoology, comparative anatomy, embryology, ecology, ethology, parasitology, entomology, ichthyology, herpetology, ornithology, mammalogy; history of zoological study with reference to Aristotle, Linnaeus, Cuvier, Darwin, and major contributors to taxonomy and evolutionary biology
  • Classification systems: objectives and principles of classification; artificial, natural, and phylogenetic classification systems; binomial nomenclature (Linnaean system — genus + species); rules of zoological nomenclature (ICZN — International Code of Zoological Nomenclature); hierarchical classification (Kingdom → Phylum → Class → Order → Family → Genus → Species)
  • Two-kingdom system, five-kingdom system (Whittaker 1969), and three-domain system (Woese and Fox 1990): placement of animals; comparison; current phylogenetic perspectives
  • Concept of species: biological species concept (Mayr — reproductive isolation); morphological species concept; phylogenetic species concept; difficulties in defining species
  • Fundamental concepts in animal organization:
    • Symmetry: asymmetry (Porifera), radial symmetry (Cnidaria, Echinodermata), bilateral symmetry (all higher animals); significance of symmetry in animal evolution
    • Body plan: levels of organization — cellular (Protozoa), cell-aggregate (Porifera), tissue (Cnidaria), organ (Platyhelminthes), organ system (Annelida and above)
    • Body cavity (coelom): acoelomate (Platyhelminthes), pseudocoelomate (Aschelminthes), eucoelomate — schizocoelous (Annelida, Arthropoda, Mollusca) and enterocoelous (Echinodermata, Chordata); significance of coelom in animal evolution
    • Segmentation (metamerism): definition; homonomous and heteronomous segmentation; examples in Annelida, Arthropoda, Chordata; evolutionary significance
    • Germ layers: diploblastic (ectoderm + endoderm — Cnidaria) vs. triploblastic (ectoderm + mesoderm + endoderm — Platyhelminthes and above); significance in organ system development
  • Phylogeny of animal kingdom: concept of phylogeny; major phylogenetic hypotheses for animal relationships; protostomes vs. deuterostomes (cleavage pattern, blastopore fate, coelom formation); lophotrochozoa, ecdysozoa, and deuterostomia as major animal clades; cladistic analysis (concept); molecular phylogenetics and its impact on traditional classification
  • Fauna of Nepal: overview of animal diversity — invertebrates and vertebrates; major taxonomic groups represented; Nepal as part of the Indo-Burma biodiversity hotspot; faunal zones (Terai, Hills, Mountains) and their characteristic fauna; threatened and endemic species (snow leopard, red panda, one-horned rhinoceros, Bengal tiger, gangetic dolphin, gharial — overview); role of protected areas in conserving Nepal’s fauna

Unit 2: Protozoa (20 teaching hours)

This unit covers the unicellular eukaryotic animals — protozoans — in systematic detail, with special emphasis on medically important species of direct relevance to Nepal’s public health.

  • General characteristics: unicellular nature; eukaryotic; heterotrophic nutrition; diverse locomotion organelles (flagella, cilia, pseudopodia, gliding); reproduction by binary fission, multiple fission, budding, conjugation; encystment and excystment; ecological and medical importance
  • Classification: Whittaker’s Protista and modern classification into four major groups by locomotion organelle — Mastigophora (Flagellata), Sarcodina (Rhizopoda), Ciliophora (Ciliata), Sporozoa (Apicomplexa)

Euglena viridis (Mastigophora — Flagellata)

  • Systematic position: Phylum Sarcomastigophora → Subphylum Mastigophora → Class Phytomastigophorea → Order Euglenida → Genus Euglena
  • Habit and habitat: freshwater ponds and pools rich in organic matter; forms green scum; solitary, free-living
  • Morphology: spindle-shaped to oval; flexible pellicle (euglenoid movement); anterior gullet and reservoir; two flagella (one long emergent, one short within reservoir); contractile vacuole; eyespot (stigma); chloroplasts; paramylum (food reserve); nucleus
  • Nutrition: holophytic (photosynthetic in light); saprophytic (in darkness — animal-like); mixotrophic nature; debate on plant vs. animal classification
  • Reproduction: asexual only — longitudinal binary fission (starting from flagellar end); palmella stage; cyst formation (unfavourable conditions)
  • Significance: indicator of organic pollution in water; model organism in cell biology; nutritional supplement research (Spirulina connection); represents transitional position between plants and animals

Paramecium caudatum (Ciliophora — Ciliata)

  • Systematic position: Phylum Ciliophora → Class Oligohymenophorea → Order Peniculida → Genus Paramecium
  • Habit and habitat: freshwater — stagnant water, ponds, puddles, decaying organic matter
  • Morphology: slipper-shaped; pellicle with hexagonal depressions; cilia covering entire body surface; oral groove, buccal cavity, cytostome, cytopharynx; trichocysts (defense); two contractile vacuoles with radiating canals; macronucleus (vegetative functions) and micronucleus (reproduction); food vacuoles
  • Locomotion: ciliary movement — effective and recovery stroke; coordination by infraciliary system; steering by reversing ciliary beat
  • Nutrition: holozoic — bacteria and algae swept into buccal cavity by oral cilia; food vacuole formation; intracellular digestion; egestion through cytopyge
  • Respiration and excretion: through general body surface; nitrogenous waste as ammonia; contractile vacuoles for osmoregulation
  • Reproduction:
    • Asexual: transverse binary fission — macronucleus divides amitotically; micronucleus divides mitotically; two daughter cells
    • Sexual: conjugation (temporary union of two compatible mating types — exchange of micronuclei; fertilization; separated; each undergoes nuclear reorganization); autogamy (self-fertilization — macronucleus disintegrates, micronucleus undergoes meiosis, nuclear fusion within single organism)
  • Life cycle diagram: conjugation cycle fully labeled

Monocystis lumbrici (Sporozoa — Apicomplexa — Gregarines)

  • Systematic position: Phylum Apicomplexa → Class Conoidasida → Order Eugregarinida → Genus Monocystis
  • Habit and habitat: endoparasite in seminal vesicles and seminal funnels of earthworm (Pheretima posthuma)
  • Morphology: trophozoite (mature) — elongated, spindle-shaped, uninucleate; lacks apical complex in adult; vermicular movement (myonemes); no mouth — absorptive nutrition
  • Life cycle: three phases — schizogony (asexual multiplication — not prominent in Monocystis; occurs within host sperm mother cells), gametogony (formation of gametes within gametocysts — two trophozoites associate as syzygy → enclose in gametocyst → each forms numerous gametes → isogametes fuse → zygotes), sporogony (zygote develops into oocyst → meiosis → 8 sporozoites in each oocyst — banana-shaped → oocysts released; new host (earthworm) infected by ingesting sporocysts from soil → sporozoites released → infect seminal vesicles)
  • Life cycle diagram: complete labeled diagram showing three phases

Plasmodium vivax (Sporozoa — Apicomplexa)

  • Systematic position: Phylum Apicomplexa → Class Conoidasida → Order Haemosporida → Genus Plasmodium
  • Habit: endoparasite with two hosts — human (intermediate host — asexual stages) and female Anopheles mosquito (definitive host — sexual stages)
  • Life cycle in human host:
    • Pre-erythrocytic (exo-erythrocytic) schizogony: sporozoites injected by mosquito bite → liver parenchyma cells → trophozoite → schizont (cryptozoite) → merozoites (cryptomerozoites) → released from liver; some form hypnozoites (dormant — cause relapses in P. vivax)
    • Erythrocytic schizogony: merozoites enter RBCs → ring stage trophozoite (Schüffner’s dots in P. vivax — characteristic) → growing trophozoite (amoeboid) → schizont → 12–24 merozoites → rupture of RBC (every 48 hours — causing tertian fever) → merozoites reinfect new RBCs; cycle continues
    • Gametogony: some merozoites → microgametocytes (male) and macrogametocytes (female) — remain in RBCs; taken up by feeding mosquito
  • Life cycle in mosquito host:
    • In mosquito midgut: RBC ruptures; microgametocyte → 8 microgametes (exflagellation); macrogametocyte → macrogamete; fertilization → zygote → ookinete (motile)
    • Sporogony: ookinete penetrates midgut wall → oocyst → sporozoites (1000s) → oocyst ruptures → sporozoites migrate to salivary glands → injected into new human host during bite
  • Pathogenicity: malaria — fever, chills, rigors occurring every 48 hours (tertian pattern) in P. vivax; anaemia; splenomegaly; haemoglobinuria (blackwater fever — mainly P. falciparum); cerebral malaria (P. falciparum — most dangerous); comparison of all four species (P. vivax, P. falciparum, P. malariae, P. ovale) — periodicity, severity, RBC preference, diagnostic features
  • Distribution in Nepal: P. vivax predominantly in Terai districts — Jhapa, Kanchanpur, Bardiya, Kailali; seasonal transmission (monsoon peak); DHM/EDCD elimination programme
  • Life cycle diagram: complete labeled diagram (human and mosquito cycles)

Unit 3: Non-Chordata I — From Porifera to Annelida (55 teaching hours — largest unit)

Phylum Porifera (Sponges) — 8 hours

  • General characteristics: sessile, aquatic (mostly marine, some freshwater), multicellular but without true tissues; cellular level of organization; body with pores (ostia) and canals; choanocytes (collar cells); internal skeleton (spicules — calcareous, siliceous; or spongin fibres); no nervous system; high regenerative ability
  • Classification: Class Calcarea (calcareous spicules — Sycon, Leucosolenia), Class Hexactinellida (6-rayed siliceous spicules — Euplectella — Venus’s flower basket), Class Demospongiae (siliceous spicules + spongin or spongin only — Spongilla, Euspongia — commercial sponge)
  • Canal systems: asconoid (simple — Leucosolenia), syconoid (folded — Sycon), leuconoid (most complex, most efficient — Spongilla); comparison and evolutionary significance
  • Sycon (Scypha): systematic position; morphology (vase-shaped, solitary, marine); internal structure — wall structure (incurrent canals, radial canals, excurrent canals, spongocoel, osculum); cells — pinacocytes, choanocytes (collar cells), amoebocytes (archaeocytes), porocytes, scleroblasts; water current mechanism (choanocyte flagella → through ostia → incurrent canals → prosopyles → radial canals → apopyles → spongocoel → osculum); reproduction — asexual (budding, gemmules in freshwater Spongilla), sexual (hermaphrodite — sperms released, eggs fertilized in mesohyl → amphiblastula larva → parenchymula larva → settles → adult); life cycle diagram; economic importance of sponges (bath sponges, silica in glassware, surgical absorbents, bioindicators)

Phylum Cnidaria (Coelenterata) — 10 hours

  • General characteristics: aquatic (mostly marine); radially symmetrical; diploblastic (ectoderm + endoderm with mesoglea); tissue level of organization; cnidocytes (nematocysts) — unique stinging cells; gastrovascular cavity (coelenteron) — single opening serves as mouth and anus; polymorphism (polyp — sessile; medusa — free-swimming); nerve net (first nervous system in animals); no excretory system; reproduction by alternation of generations (metagenesis); ecological importance (coral reefs — marine biodiversity hotspots)
  • Classification: Class Hydrozoa (Hydra, Obelia, Physalia — Portuguese man-of-war); Class Scyphozoa (true jellyfish — Aurelia); Class Anthozoa (sea anemones, corals — Metridium, Fungia); Class Cubozoa (box jellies — Chironex)
  • Obelia (Hydrozoa): systematic position; colonial hydroid form; structure of colony — stolon, hydrocaulus, hydrotheca, gonotheca; polymorphism — nutritive polyp (hydranth/gastrozooid — feeding) and reproductive polyp (gonozooid/blastostyle — produces medusae); structure of hydranth — hypostome, tentacles, cnidocytes; asexual reproduction (budding within colony); sexual reproduction (medusa produced by blastostyle → free-swimming → medusa has gonads → gametes → fertilization → planula larva → settles → new hydroid colony); alternation of generations (metagenesis); life cycle diagram; economic importance of Cnidaria (coral reefs — tourism, fisheries, biodiversity; nuisance of jellyfish blooms)

Phylum Platyhelminthes (Flatworms) — 10 hours

  • General characteristics: bilaterally symmetrical; dorsoventrally flattened; acoelomate; triploblastic; organ level of organization; no circulatory or respiratory system; protonephridia for excretion (flame cells); nervous system — ladder-type with ganglia; hermaphroditic; complex life cycles with larval stages; free-living (Turbellaria) and parasitic (Trematoda, Cestoda) forms
  • Classification: Class Turbellaria (free-living — Planaria); Class Trematoda (flukes — Fasciola, Schistosoma); Class Cestoda (tapeworms — Taenia, Echinococcus)
  • Fasciola hepatica (Liver Fluke — Trematoda): systematic position; habit and habitat (adult in bile ducts of sheep, cattle, occasionally humans); morphology (leaf-shaped; oral sucker, ventral sucker/acetabulum; tegument; no mouth separate from sucker); internal anatomy (digestive — branched intestine; excretory — protonephridia, flame cells; reproductive — hermaphrodite — complex male and female organs — testes, ovary, Mehlis’ gland, Laurer’s canal, vitellaria); life cycle (adult in sheep bile ducts → eggs passed in faeces → miracidium (ciliated free-swimming larva) → enters Lymnaea (snail — intermediate host) → sporocyst → redia → cercaria → released from snail → encysts as metacercaria on aquatic vegetation → ingested by sheep → excysted → migrates to bile ducts → adult); pathogenicity — liver rot (fascioliasis) — hepatic damage, bile duct obstruction; diagnosis; treatment; control; distribution in Nepal
  • Taenia solium (Pork Tapeworm — Cestoda): systematic position; habit and habitat (adult in human small intestine; larva in pig muscles); morphology — scolex (holdfast — 4 suckers + rostellum with hooks — helps distinguish T. solium from T. saginata which lacks rostellum), neck (region of growth), strobila (chain of proglottids — immature, mature, gravid); tegument (absorbs nutrients directly — no digestive system); proglottid structure — mature proglottid (hermaphrodite — testes, vas deferens, cirrus; ovary, vagina, uterus, vitellaria); gravid proglottid (uterus packed with eggs); life cycle (gravid proglottids/eggs shed in faeces → pig ingests eggs → hexacanth embryo (oncosphere) released in pig intestine → penetrates gut wall → migrates to muscles → develops into cysticercus cellulosae (bladder worm — scolex + fluid-filled bladder) → human eats undercooked pork → scolex evaginates in intestine → attaches → grows into adult tapeworm); cysticercosis in humans (if human ingests eggs — larvae form cysts in brain — neurocysticercosis — serious neurological condition; commonest cause of acquired epilepsy in developing countries); taeniasis and cysticercosis in Nepal — public health burden in communities consuming undercooked pork; pathogenicity; diagnosis; treatment; control; life cycle diagram

Phylum Aschelminthes (Nemathelminthes — Roundworms) — 7 hours

  • General characteristics: bilaterally symmetrical; pseudocoelomate (body cavity not lined by mesodermal peritoneum); cylindrical, unsegmented body; complete digestive system (mouth to anus — first phylum with anus); cuticle (resistant — allows survival in harsh environments); longitudinal muscles only (causes thrashing motion); protonephridia or no excretory system; no circulatory or respiratory system; dioecious (sexes separate); sexual dimorphism (females larger than males); resistant eggs; many are parasites of animals and plants
  • Classification: Class Nematoda (roundworms — Ascaris, Wuchereria, Enterobius, Ancylostoma, Strongyloides, Trichinella); Class Rotifera; Class Gastrotricha; Class Nematomorpha
  • Ascaris lumbricoides (Giant Intestinal Roundworm — Nematoda): systematic position; habit and habitat (adult in small intestine of humans — also pigs); morphology — size (females 20–35 cm, males 15–30 cm with curved posterior end; cuticle with four longitudinal lines — dorsal, ventral, two lateral); cross-section anatomy — cuticle, hypodermis (syncytial), muscle layer (longitudinal only), pseudocoelom, intestine, reproductive organs; alimentary canal — mouth (3 lips), pharynx (muscular), intestine, rectum, anus; nervous system — nerve ring, ventral and dorsal nerve cords; excretory system — H-shaped system with lateral canals and excretory pore; reproductive system — female (two ovaries, oviducts, uteri — meet at vagina; enormous reproductive capacity — 200,000 eggs/day); male (two testes, vas deferens, seminal vesicle, ejaculatory duct, spicules — chitinous copulatory organs); life cycle: eggs passed in faeces → embryonated eggs (infective stage — contain L2 larva) → ingested by human → hatch in small intestine → L3 larvae → penetrate gut wall → liver (via portal vein) → heart → lungs → trachea → swallowed → small intestine → L4 → adult (Löffler’s syndrome — pulmonary migration phase causing eosinophilia, cough, fever); pathogenicity — intestinal obstruction, bile duct obstruction, malnutrition, growth retardation in children; ascariasis prevalence in Nepal — particularly in children in rural areas where sanitation is poor; diagnosis (stool O&P — eggs); treatment (albendazole, mebendazole); control (sanitation, hand washing, deworming programmes); life cycle diagram
  • Wuchereria bancrofti (Filarial Worm — Nematoda): systematic position; habit and habitat (adult in lymphatic vessels and nodes of humans; microfilariae in peripheral blood — nocturnal periodicity; intermediate host — Culex mosquito); morphology — adult (thread-like, white; males 40 mm, females 60–100 mm); life cycle: adult worms in lymphatics → females release microfilariae (sheathed — L1 larvae) → microfilariae circulate in peripheral blood (nocturnal — 10 PM – 2 AM peak) → ingested by female Culex mosquito during night blood meal → L1 → L2 → L3 (infective stage in mosquito mouthparts) → deposited on human skin during bite → enter skin through bite wound → lymphatics → L4 → adult (takes 6–12 months); pathogenicity — lymphangitis, lymphadenopathy, elephantiasis (lymphoedema of limbs and genitalia — due to repeated infection causing chronic lymphatic obstruction and inflammatory response); hydrocele; tropical pulmonary eosinophilia; lymphatic filariasis in Nepal — endemic in Terai districts; National Programme for Elimination of Lymphatic Filariasis (mass drug administration — DEC + albendazole); diagnosis (night blood smear for microfilariae; ICT card test for circulating antigen); life cycle diagram

Phylum Annelida (Segmented Worms) — 10 hours

  • General characteristics: bilaterally symmetrical; triploblastic; eucoelomate (true coelom — schizocoelous); metamerically segmented body (true segmentation — each segment separated by septa); complete digestive system; closed circulatory system (first in invertebrates — blood in vessels); excretion by nephridia (metanephridia in most — open coelomostome + nephridiopore); nervous system — ventral nerve cord with ganglia per segment; locomotion by setae (chaetae) and coelom as hydrostatic skeleton; hermaphroditic (Oligochaeta) or dioecious (Polychaeta); aquatic and terrestrial; ecological importance (soil fertility, food for higher animals)
  • Classification: Class Polychaeta (mostly marine, with parapodia and setae — Nereis, Sabella, Aphrodite); Class Oligochaeta (few setae, no parapodia — Pheretima, Lumbricus); Class Hirudinea (leeches — no setae, anterior and posterior suckers — Hirudo)
  • Pheretima posthuma (Indian Earthworm — Oligochaeta): systematic position; habit and habitat (moist soil rich in organic matter; nocturnal; found throughout Nepal in agricultural and garden soils)
    • External morphology: cylindrical; segments (metameres) — 100–120; clitellum (segments 14–16 — saddle-shaped glandular structure for cocoon formation); prostomium; mouth (segment 1); anus (last segment); dorsal pore (from segment 12 onwards — exudes coelomic fluid); setae arrangement (8 per segment in two pairs — ventrolateral and lateral positions on each segment); genital apertures — male pores (segment 18), female pore (segment 14), spermathecal pores (4 pairs — segments 5/6, 6/7, 7/8, 8/9)
    • Internal anatomy:
      • Digestive system: mouth → buccal cavity (1–2) → pharynx (3–4) → oesophagus (5–7) → gizzard (8–9 — muscular grinding organ) → stomach (9–14 — calciferous glands for neutralizing soil acids) → intestine (15 onwards — internal typhlosole dorsal fold increasing surface area) → anus; digestion and absorption
      • Circulatory system: closed; dorsal blood vessel (blood flows anteriorly); ventral blood vessel (blood flows posteriorly); lateral hearts (pairs in segments 7, 9, 12, 13 — muscular aortic arches pumping blood from dorsal to ventral); subneural blood vessel; blood composition — haemoglobin dissolved in plasma (not in cells)
      • Excretory system: nephridia — three types: septal nephridia (on septa from segment 15 onwards — open into intestine — enteronephric); integumentary nephridia (on body wall — open externally — exonephric); pharyngeal nephridia (in segments 4–6 — open into pharynx — enteronephric); nephridium structure — nephrostome (ciliated funnel), ciliated tubule, glandular part, muscular part, bladder, nephridiopore
      • Nervous system: supra-pharyngeal ganglia (“brain” — segment 3) + connectives → sub-pharyngeal ganglia → ventral nerve cord (double, fused) → paired ganglia per segment → segmental nerves; sensory cells in body wall
      • Reproductive system: hermaphroditic; cross-fertilization only; testes (2 pairs — segments 10, 11 — in testis sacs); seminal vesicles (3 pairs); seminal funnels; vas deferens; prostate glands; male pores (segment 18); ovaries (1 pair — segment 13); oviducts; female pore (segment 14); spermathecae (4 pairs — store spermatozoa received during copulation)
      • Cocoon formation: clitellum secretes mucous ring → worm backs out → eggs + stored spermatozoa deposited → closed at both ends to form cocoon → young earthworms emerge
    • Life cycle diagram: reproductive cycle and cocoon formation
    • Economic importance: vermicomposting (worm castings — rich in nitrogen, phosphorus, potassium — natural fertilizer); soil aeration and drainage; soil mixing; bait for fishing; food for birds; indicators of soil health; earthworm cultivation (vermiculture) as livelihood option in Nepal
  • Hirudo medicinalis (Leech — Hirudinea): systematic position; morphology (leaf-shaped; anterior and posterior suckers; 33 segments but external annuli give appearance of more; no setae; no parapodia); internal anatomy (digestive system with crop having pouches for blood storage; circular and longitudinal muscles; hermaphroditic); anticoagulant secretion (hirudin); habit (freshwater ponds; ectoparasite — feeds on blood of vertebrates); medical use (hirudotherapy — bloodletting, reconstructive surgery to prevent clot formation; leeching in traditional medicine); economic importance

Unit 4: Non-Chordata II — From Arthropoda to Echinodermata (35 teaching hours)

Phylum Arthropoda (Joint-legged Animals) — 15 hours

  • General characteristics: largest phylum in the animal kingdom (>80% of all known species); bilaterally symmetrical; triploblastic; eucoelomate (coelom greatly reduced — haemocoel predominant); metamerically segmented; jointed appendages (arthropodium) — one pair per segment; exoskeleton of chitin (provides protection, attachment for muscles — moulted periodically — ecdysis); open circulatory system (blood — haemolymph — in haemocoel); respiration by gills (aquatic), book lungs (arachnids), tracheal system (insects, myriapods); excretion by green glands (Crustacea), Malpighian tubules (insects, arachnids); brain (protocerebrum + deutocerebrum + tritocerebrum); compound eyes (in many); dioecious; economic importance (bees — pollination and honey; silkworm — silk; shellfish — food; insect vectors of disease; pest control)
  • Classification:
    • Subphylum Trilobita: extinct (Paleozoic)
    • Subphylum Chelicerata: Class Merostomata (horseshoe crabs — Limulus); Class Arachnida (spiders, scorpions, ticks, mites — Argiope, Scorpio, Sarcoptes, Ixodes)
    • Subphylum Crustacea: Class Branchiopoda (Daphnia — water flea); Class Cirripedia (barnacles — Balanus); Class Malacostraca (crayfish, crabs, prawns, lobsters — Palaemon, Cambarus, Carcinus)
    • Subphylum Myriapoda: Class Chilopoda (centipedes — Scolopendra); Class Diplopoda (millipedes — Julus)
    • Subphylum Hexapoda/Insecta: Class Insecta — 6 legs; 3 body parts (head, thorax, abdomen); wings (in most); most diverse animal class
  • Palaemon (Freshwater Prawn — Crustacea): systematic position; habitat (freshwater rivers, streams — Nepal has significant prawn fisheries in Terai rivers); external morphology — cephalothorax (head + thorax fused, covered by carapace) + abdomen (6 segments + telson); appendages — antennules (2), antennae (2), mandibles, maxillules, maxillae, 3 pairs of maxillipeds, 5 pairs of pereiopods (walking legs — chelate first 2 pairs), 5 pairs of pleopods (swimming legs), uropods (with telson form tail fan for backward escape swimming); internal anatomy — digestive (cardiac stomach with gastric mill, pyloric stomach with filter, digestive gland — hepatopancreas, intestine); circulatory (open — heart with ostia, arteries, haemocoel); excretory (green glands/antennal glands in base of antennae); nervous system (brain + ventral nerve cord with ganglia); reproductive (dioecious; female carries eggs under pleopods); economic importance (food fisheries; aquaculture potential in Nepal)
  • Insects — General: Class Insecta characters; metamorphosis — ametabolous (no metamorphosis — silverfish), hemimetabolous (incomplete — grasshopper, cockroach — egg → nymph → adult), holometabolous (complete — butterfly, fly, bee — egg → larva → pupa → adult); importance in Nepal — bees (honey production — traditional beekeeping; pollination of agricultural crops — cardamom, mustard, apple); silkworm (Bombyx mori — silk industry); mosquitoes (vectors — Anopheles for malaria, Culex for filariasis, Aedes for dengue and Japanese encephalitis — major public health concerns in Nepal); locust (agricultural pest)
  • Periplaneta americana (American Cockroach — Insecta): systematic position; habitat (omnivorous household pest; nocturnal; found throughout Nepal in urban environments); external morphology — head (compound eyes, antennae, mouthparts — mandibles, maxillae, labium, labrum, hypopharynx — biting-chewing type), thorax (pronotum, mesonotum, metanotum; 3 pairs of legs; 2 pairs of wings — tegmina [leathery forewings] + membranous hindwings), abdomen (10 segments; cerci; anal styles in male; ootheca formation); internal anatomy — digestive system (crop, gizzard, midgut with 8 gastric caecae, malpighian tubules 60–150 — excretory function, hindgut, rectum); circulatory system (open — dorsal heart with 13 chambers and ostia; haemolymph); respiratory system (tracheal system — 10 pairs of spiracles; tracheae and tracheoles — oxygen directly to tissues); nervous system (cerebral ganglia/brain; ventral nerve cord — 6 abdominal ganglia + thoracic + suboesophageal ganglia); reproductive system (dioecious; male — 2 testes, accessory glands, phallomere; female — 2 ovaries, colleterial glands — form ootheca; ootheca contains 14–16 eggs; nymphs hatch — hemimetabolous)

Phylum Mollusca — 10 hours

  • General characteristics: second largest animal phylum (after Arthropoda); bilaterally symmetrical (secondary asymmetry in gastropods due to torsion); triploblastic; eucoelomate (reduced); soft-bodied, unsegmented; distinctive body plan — head-foot (locomotion, sensing), visceral mass (organs), mantle (secretes shell — CaCO₃); radula (rasping feeding organ — absent in bivalves); open circulatory system (except Cephalopoda); respiration by ctenidia (gills) or pulmonary cavity (land snails); excretion by nephridia; varied reproduction; economic importance (food — snails, mussels, oysters, squid, octopus; nacre and pearls from oysters; cone snail venom; schistosomiasis — snail intermediate host)
  • Classification: Class Polyplacophora (chitons — Chiton); Class Gastropoda (snails, slugs — Pila, Helix, Limax — largest class); Class Bivalvia/Pelecypoda (clams, oysters, mussels — Unio, Ostrea, Mytilus); Class Cephalopoda (squids, octopus, nautilus — Octopus, Loligo, Sepia, Nautilus)
  • Pila globosa (Apple Snail — Gastropoda): systematic position; habit and habitat (freshwater ponds, rice fields — Nepal’s Terai rice paddies; amphibious); morphology — spiral shell (sinistral or dextral; spire; sutures; aperture; operculum — horny plate closing aperture when retracted); foot (broad muscular — locomotion); head (2 pairs of tentacles — upper pair with eyes; mantle cavity divided — aquatic gill + pulmonary sac for aerial breathing — amphibious adaptation); torsion (180° rotation of visceral mass during development — characteristic gastropod feature); internal anatomy — digestive (buccal mass with radula — scraping feeding; stomach; digestive gland; intestine; anus into mantle cavity); circulatory (open — 2-chambered heart — one auricle + one ventricle; haemocoel); respiratory (ctenidium [gill] for water breathing + pulmonary sac [lung] for air breathing — adaptation for seasonal drought in Nepal’s paddy fields); excretory (nephridium — kidney); nervous system (ganglia — cerebral, pedal, pleural, visceral — connected by nerve cords); reproductive (dioecious; female with oviduct; male with penis; eggs laid in clusters on vegetation above water); economic importance (edible; intermediate host for Angiostrongylus cantonensis — rat lungworm causing eosinophilic meningitis)
  • Unio (Freshwater Mussel — Bivalvia): systematic position; habit and habitat (freshwater rivers and streams — Nepal’s rivers contain native freshwater mussel species); morphology — two valves (shells) joined by hinge ligament; hinge teeth (interlocking); pallial line and sinus; external (periostracum — outer protein layer), prismatic (crystalline CaCO₃), nacreous (mother of pearl — inner layer — produces pearls) layers; foot (axe-shaped — burrowing); siphons (inhalant and exhalant); internal anatomy — mantle (secretes shell; encloses mantle cavity); gills (ctenidia — 2 pairs — lamellibranch; modified for filter feeding — mucus traps food particles → labial palps → mouth; water flow driven by gill cilia); digestive (stomach with crystalline style; digestive gland; intestine); circulatory (open — 3-chambered heart — 2 auricles + 1 ventricle; rectum passes through ventricle in some species); excretory (nephridia); nervous system (3 pairs of ganglia — cerebro-pleural, pedal, visceral); reproductive (dioecious or hermaphroditic; larvae — glochidium parasite on fish gills — obligatory for completing life cycle); economic importance (freshwater pearls; food; water quality indicator — mussel mortality signals pollution)

Phylum Echinodermata — 10 hours

  • General characteristics: exclusively marine; adults radially symmetrical (5-fold — pentamerous), larvae bilaterally symmetrical; deuterostome (embryological link to Chordata); triploblastic; eucoelomate; endoskeleton of calcareous ossicles (mesodermal origin — unique); water vascular system (hydraulic system using sea water — locomotion, food capture, gas exchange, excretion — unique to Echinodermata); ambulacral grooves and tube feet (podia); open circulatory system; no excretory organs; haemal system (poorly understood blood vascular system); high regenerative ability; no brain; diffuse nervous system; dioecious; separate sexes; external fertilization; larvae free-swimming (bipinnaria, brachiolaria, ophiopluteus, echinopluteus, doliolaria — vary by class); ecological importance (coral reef community, bioturbation, sea urchin grazing)
  • Classification: Class Asteroidea (sea stars — Asterias); Class Ophiuroidea (brittle stars — Ophiura); Class Echinoidea (sea urchins — Echinus, Clypeaster); Class Holothuroidea (sea cucumbers — Holothuria); Class Crinoidea (sea lilies, feather stars — Antedon)
  • Asterias (Starfish — Asteroidea): systematic position; habit and habitat (rocky seashores and shallow marine environments — not endemic to Nepal but studied as representative echinoderm); morphology — central disc + 5 arms (rays); aboral surface (dorsal — madreporite — entry point for water vascular system; spines; pedicellariae; papulae — dermal gills for gas exchange); oral surface (ventral — ambulacral grooves with tube feet in rows; mouth centrally); internal anatomy — body wall (epidermis, dermis with ossicles and spines, muscles, peritoneum); coelom (spacious — houses organs, bathes in coelomic fluid); water vascular system (madreporite → stone canal → ring canal → radial canals → lateral canals → ampullae → tube feet — suckers; mechanism of tube foot extension and attachment — ampulla contraction squeezes fluid into tube foot); digestive system (cardiac stomach [evertable through mouth for extracorporeal digestion of bivalve prey — wraps around prey, digests externally], pyloric stomach, pyloric caeca [paired per arm — digestion and absorption], short intestine, anus [aboral]); hemal system; nervous system (nerve ring + radial nerve cords + epidermal plexus); reproductive system (dioecious; gonads [pairs per arm] — shed gametes into seawater; fertilization external; bipinnaria → brachiolaria → settle → metamorphose into juvenile starfish); regeneration (lost arms regenerate — if disc is intact; some species reproduce by fission); economic importance (predators of molluscs — pest in oyster farms; regeneration research; indicator species; ecotourism)

Unit 5: Protochordata (25 teaching hours)

Protochordata represents the invertebrate-chordate transition — animals that possess some but not all chordate characteristics, providing crucial evidence for the origin of vertebrates.

  • Definition and significance: protochordates possess some chordate characters (notochord, pharyngeal gill slits, dorsal hollow nerve cord — in some stages) but lack a true vertebral column; they occupy the evolutionary bridge position between invertebrates and true chordates; study of their embryology and adult morphology provides key evidence for chordate origins and vertebrate evolution
  • Phylum Hemichordata: characters (worm-like; marine; tripartite body — proboscis + collar + trunk; gill slits; no true notochord — buccal diverticulum only — not homologous; collar cord; open circulatory system; dioecious); classification — Class Enteropneusta (acorn worms — Balanoglossus, Saccoglossus); Class Pterobranchia (Cephalodiscus, Rhabdopleura)
  • Balanoglossus (Acorn Worm — Hemichordata — Enteropneusta): systematic position; habit and habitat (marine; burrows in sand and mud; Indo-Pacific and Atlantic ocean shores); morphology — cylindrical worm (10 cm – 2.5 m); three body regions — proboscis (conical, muscular, ciliated — burrowing and feeding; lined by proboscis coelom — proboscoel); collar (short, cylindrical; surrounds anterior part of trunk; collar coelom — mesocoel; collar cord — hollow nerve tissue — chorda-like); trunk (long; gill region with pharyngeal gill slits; hepatic sacs [greenish — digestive]; genital region; abdominal region; posterior; anus at tip); internal anatomy — alimentary canal (mouth beneath collar → buccal cavity with buccal diverticulum [NOT a true notochord — important distinction] → pharynx with gill slits — ciliated for filter feeding → oesophagus → hepatic region → intestine → anus); coelom (protocoel, mesocoel, metacoel — tripartite); circulatory system (open — dorsal and ventral vessels; glomerulus — excretory); nervous system (dorsal nerve cord in collar region; ventral nerve cord in trunk; diffuse epidermis nerve net); reproductive (dioecious; gonads in rows along genital region; external fertilization; tornaria larva — superficially similar to bipinnaria larva of starfish — evidence for deuterostome relationship); tornaria larva: structure, similarity to echinoderm larvae, significance as evolutionary evidence; life cycle diagram; economic/evolutionary importance of Balanoglossus

Urochordata (Tunicata) — 10 hours

  • General characteristics: exclusively marine; solitary or colonial; adults sessile (lose chordate characters in metamorphosis — regressive metamorphosis); larvae (tadpole larva) possess all three chordate characters — notochord (in tail only), dorsal hollow nerve cord, pharyngeal gill slits; tunic (test) of tunicin (cellulose-like polysaccharide — unique among animals); filter feeders; closed circulatory system with reversible heartbeat; excretion by accumulation (storage excretion); hermaphroditic; asexual reproduction by budding; three classes
  • Classification: Class Ascidiacea (sea squirts — sessile adults — Ciona, Herdmania, Botryllus); Class Thaliacea (free-swimming — salps — Salpa); Class Larvacea/Appendicularia (neotenic — retain larval form throughout life — Oikopleura)
  • Herdmania (Sea Squirt — Ascidiacea — Urochordata): systematic position; habit and habitat (sessile; attached to rocks, shells, piers in shallow marine water; solitary); external morphology — barrel or sac-shaped body; two siphons — inhalant (oral/buccal siphon) and exhalant (atrial/cloacal siphon) — used for filter feeding and water circulation; tunic (thick, tough outer covering — tunicin + protein); internal anatomy — body wall (tunic + mantle — with muscles and blood vessels); atrium (surrounds pharynx); pharynx (basket-like — wall perforated by numerous stigmata/gill slits — pharyngeal sac; lined with cilia and mucus for filter feeding — food trapped in mucous sheet secreted by endostyle → food groove → oesophagus); endostyle (mucus and iodine-binding gland on pharyngeal floor — homologous to thyroid gland of vertebrates — major evolutionary significance); digestive system (oesophagus → stomach → intestine → rectum → opens into atrium → exhalant siphon); circulatory system (open — simple tubular heart with alternating contraction direction — reversal of blood flow every few minutes — unique feature); nervous system (adult — ganglionic; cerebral ganglion between two siphons; no dorsal hollow nerve cord in adult — regressed); excretory system (no specialized organs — pylosomes for storage excretion); reproductive system (hermaphroditic — ovary + testis; gametes released into atrium → fertilization external or in atrium → tadpole larva → metamorphosis); tadpole larva: structure (free-swimming; tail contains notochord and dorsal hollow nerve cord; pharyngeal gill slits in trunk; sensory organs — ocellus for light, statocyst for gravity; represents ancestral chordate state); metamorphosis: tadpole settles and undergoes regressive metamorphosis — tail with notochord and nerve cord resorbed; body reorganized; adult loses most chordate characters (except pharyngeal slits and endostyle); evolutionary significance of Urochordata; life cycle diagram

Cephalochordata — 5 hours

  • General characteristics: fish-like; marine; shallow sandy sea floors; possess all three chordate characters throughout life — notochord (extends from anterior tip to posterior — hence “cephalochordata” — cephalic notochord), dorsal hollow nerve cord, pharyngeal gill slits; also have: myotomes (V-shaped muscle blocks — precursors of vertebrate body muscles), metapleural folds (possible precursors of paired fins/limbs), hepatic caecum (liver homologue), gill bars, circulatory system without heart; filter feeders; no distinct head (hence “Acrania — headless”); simple nervous system (no brain as such — anterior expansion of nerve cord); dioecious; external fertilization; true segmentation (myotomes)
  • Classification: Family Branchiostomidae — Genus Branchiostoma (Amphioxus = Lancelet); Asymmetron
  • Branchiostoma (Amphioxus/Lancelet — Cephalochordata): systematic position; habit and habitat (shallow marine sand; cosmopolitan; burrows in sand with anterior end exposed for filter feeding; can swim; found in warm shallow seas — Indian Ocean, Western Pacific)
    • External morphology: fish-like; laterally compressed; rostrum (anterior); oral cirri (tentacle-like projections around mouth for filter feeding); wheel organ (cilia for creating feeding currents); velum (partition at pharynx entrance); fin rays (dorsal fin, ventral fin, caudal fin — composed of fin ray boxes [collagen]); atrio-pore (ventral — exhalant opening from atrium); anus (slightly left of midline — due to slight asymmetry)
    • Internal anatomy:
      • Notochord: extends from very anterior tip to posterior end; composed of disc-shaped muscle cells (not cells in other chordates — unique feature); provides rigidity for swimming; homologous to vertebral column (phylogenetically — precursor); notochord cells vacuolated with peripheral muscles — unique notochord musculature in Amphioxus
      • Nerve cord (neural tube): dorsal hollow nerve cord above notochord; slightly enlarged at anterior end (cerebral vesicle — NOT a true brain); photoreceptors (lamellar body), balance receptor (frontal eye); segmental nerves from nerve cord; spinal eye (cells with melanin) — photoreceptive
      • Pharynx: large (occupies most of body length); walls with numerous gill slits (pharyngeal clefts) with gill bars; gill bars with primary and secondary bars; endostyle (iodine-binding — homologous to thyroid gland); food trapped in mucous sheet; food groove (epibranchial groove); atrium surrounds pharynx — water exits through atrio-pore
      • Digestive system: mouth (circular — surrounded by oral cirri and wheel organ) → velum → pharynx → intestine → hepatic caecum (right side — secretes digestive enzymes — liver homologue) → intestine → anus
      • Circulatory system: closed type; no heart (pulsatile vessels — aorta and veins pulsate rhythmically); blood colourless (no haemoglobin in blood — cutaneous and branchial gas exchange); portal vein (intestine → hepatic caecum — hepatic portal system homologue); branchial arteries in gill bars
      • Excretory system: protonephridia with solenocytes (flame cells with flagella — not cilia — unique protonephridia in deuterostome — significant evolutionary feature)
      • Reproductive system: dioecious; about 26 pairs of gonads (in atrial wall segments — mesodermal origin); no ducts — gametes released into atrium → atrio-pore → external fertilization; amphioxides larva → metamorphosis
    • Evolutionary significance of Amphioxus: most chordate-like invertebrate; presence of all three chordate synapomorphies throughout life; shows primitive vertebrate organization without vertebral column; key evidence for vertebrate origin; genome of Branchiostoma lanceolatum has been sequenced — confirms it shares genes with vertebrates; used as model organism for studying vertebrate evolution
    • Life cycle diagram: showing larva and adult

Unit 6: Evolutionary Relationships and Invertebrate Biodiversity of Nepal (5 teaching hours)

  • Evolutionary relationships among non-chordates: cladistic analysis of major phyla; traditional vs. molecular phylogeny; protostome vs. deuterostome divergence; lophotrochozoa (Annelida, Mollusca, Platyhelminthes, and related phyla) vs. ecdysozoa (Arthropoda, Nematoda — share moulting); evidence from embryology (cleavage type, blastopore fate, coelom type), morphology (body plan, segmentation, symmetry), and molecular data (18S rRNA, Hox genes)
  • Invertebrate biodiversity of Nepal: general overview of invertebrate groups recorded in Nepal — soil fauna (earthworms, nematodes, arthropods as indicators of soil health); freshwater invertebrates of Nepal’s rivers and lakes (Ephemeroptera, Plecoptera, Trichoptera — EPT index as bioindicator of river health; freshwater molluscs; crustaceans); forest invertebrates (insects, spiders, scorpions); high altitude invertebrates (chironomids in Himalayan lakes and glaciers — extremophiles); parasitic invertebrates of public health significance in Nepal (Plasmodium, Ascaris, Wuchereria, Fasciola, Taenia — reviewed from earlier units in conservation biology context)
  • Threatened and endemic invertebrates of Nepal: IUCN status of selected invertebrate species; conservation challenges; gaps in invertebrate conservation policy (invertebrates often overlooked in favour of charismatic megafauna)
  • Conservation of invertebrates in Nepal: role of protected areas (Chitwan, Bardia, Koshi Tappu — freshwater invertebrate diversity); role of community forests in maintaining invertebrate diversity; citizen science approaches for invertebrate monitoring in Nepal

Zool. 102 Practical Syllabus (50 Marks, 180 Periods)

1. Protozoa

  • Preparation and study of wet mounts of Euglena (pond water culture) and Paramecium (hay infusion culture)
  • Observation of locomotion: Euglena (flagellar movement — euglenoid movement); Paramecium (ciliary movement — avoidance response)
  • Study of permanent slides: Plasmodium (thin blood films — ring stage, trophozoite, schizont, gametocyte); Monocystis (stages from earthworm seminal vesicle preparations)
  • Study of museum specimens and photomicrographs: Plasmodium vivax and P. falciparum — distinguishing features (Schüffner’s dots, banana-shaped gametocytes of P. falciparum)

2. Porifera and Cnidaria

  • Study of museum specimens: Sycon (Scypha), Euspongia (commercial bath sponge), Spongilla (freshwater sponge), Leucosolenia
  • Permanent slide study: LS/TS of Sycon (canal system, choanocytes); gemmule of Spongilla
  • Museum specimens: Obelia colony, Aurelia (jellyfish), sea anemone (Metridium), coral specimens
  • Permanent slide study: portion of Obelia colony (hydranth + gonangium); section of hydranth; Obelia medusa
  • Drawing and labeling of canal system types (ascon, sycon, leucon) from diagrams

3. Platyhelminthes and Aschelminthes

  • Museum specimens: Fasciola hepatica (whole mount), Taenia solium (scolex, proglottids), Moniezia (sheep tapeworm — for comparison)
  • Permanent slide study: Fasciola hepatica (whole mount — internal organs); mature proglottid of Taenia (hermaphrodite reproductive organs); gravid proglottid of Taenia (uterus branches — T. solium has <13 branches vs. T. saginata >13 — diagnostic)
  • Museum specimens: Ascaris lumbricoides (male and female — pinch test, sexual dimorphism); Wuchereria bancrofti (demonstration slides of microfilariae in blood smear — Giemsa stain)
  • Permanent slides: cross-section of Ascaris (cuticle, hypodermis, muscle, pseudocoelom, reproductive organs — distinction of male and female from section)
  • Study and drawing of life cycles from charts: Fasciola, Taenia, Ascaris, Wuchereria

4. Annelida

  • Study of live earthworms (Pheretima): external morphology — counting segments, identifying clitellum, dorsal pores, genital openings, setae arrangement under hand lens
  • Dissection of earthworm: dorsal dissection — exposing dorsal blood vessel, hearts, nephridia, reproductive organs (testes, seminal vesicles, ovaries, spermathecae); digestive system (pharynx, gizzard, intestine, typhlosole visible)
  • Transverse section of earthworm (permanent slide): identifying layers (cuticle, epidermis, circular muscle, longitudinal muscle, peritoneum), coelom, nephridium, ventral nerve cord, dorsal blood vessel, intestine with typhlosole
  • Study of museum specimens: Hirudo (leech — anterior and posterior suckers), Nereis (polychaete — parapodia, setae)
  • Permanent slides: nephridium of Pheretima; transverse section of Hirudo

5. Arthropoda and Mollusca

  • Study of preserved specimens: Palaemon (prawn — external morphology, appendage types); Scolopendra (centipede); Julus (millipede); Scorpio (scorpion); spider specimens
  • Dissection of Periplaneta americana (cockroach): digestive system (crop, gizzard, gastric caecae, malpighian tubules, intestine); nervous system (brain, nerve cord, ganglia); reproductive system (male and female separately)
  • Permanent slide study: wing venation of insects; mouthparts (biting-chewing in cockroach vs. sucking in mosquito/butterfly); compound eye section
  • Study of Pila globosa (apple snail): external morphology (shell measurement — spire height, body whorl, aperture); operculum; dissection — mantle, gill, pulmonary sac, digestive gland, gonad
  • Study of Unio (freshwater mussel): shell (external — hinge, umbo; internal — nacre, pallial line, muscle scars); dissection — mantle, ctenidia (gills), labial palps, digestive gland, foot
  • Museum specimens: various mollusc shells (gastropods, bivalves, cephalopod — Sepia — cuttlebone)
  • Permanent slide: glochidium larva of Unio; radula (scanning electron micrograph or prepared slide)

6. Echinodermata

  • Museum specimens: Asterias (sea star), sea urchin (Echinus — test), sea cucumber (Holothuria), brittle star (Ophiura), sea lily (Antedon)
  • Study of Asterias: aboral surface (spines, pedicellariae, madreporite, papulae); oral surface (ambulacral grooves, tube feet, mouth)
  • Dissection of Asterias (one arm removed): water vascular system (ring canal, radial canal, lateral canals, ampullae, tube feet); pyloric caecae (digestive glands); gonads; body wall ossicles
  • Permanent slides: bipinnaria larva (study and drawing); cross-section of arm of Asterias

7. Protochordata

  • Museum specimens: Balanoglossus (whole preserved specimen — proboscis, collar, trunk, gill slits); Amphioxus (Branchiostoma — whole preserved specimen — dorsal fin, oral cirri, atrio-pore, anus, myotomes visible through body wall); Herdmania (sea squirt — tunic, two siphons)
  • Permanent slide study: whole mount of Amphioxus (Branchiostoma) — identifying notochord, nerve cord, pharyngeal gill slits, myotomes, fin ray boxes, hepatic caecum, gonads; cross-section of Amphioxus through different body regions (pharyngeal region — notochord, nerve cord, endostyle, gill bars, atrium; intestinal region)
  • Permanent slides: Amphioxus cross-section (pharyngeal level); tadpole larva of tunicate; tornaria larva of Balanoglossus (if available)
  • Drawing and comparison exercise: comparison table of chordate characters in Balanoglossus, Herdmania, and Amphioxus — which characters each possesses and which are absent

8. Field Visit and Museum Work

  • Visit to Natural History Museum (Swayambhu, Kathmandu) or CDZ Zoological Museum for study of type specimens, preserved specimens of all major invertebrate groups, and Nepal-specific fauna
  • Survey of invertebrate fauna of a nearby aquatic (pond or river) or terrestrial (garden or forest) habitat; species list; dominant groups; simple food web construction; report submission
  • Collection and preservation of invertebrate specimens from the field visit; labeling and deposition in practical collection

The Four-Year TU B.Sc. Zoology Programme Structure

  • First Year (Zool. 101/102): Non-Chordata and Protochordata — invertebrate diversity from Protozoa to Protochordata
  • Second Year (Zool. 201/202): Chordata, Comparative Anatomy and Evolution — vertebrate diversity (Agnatha, Pisces, Amphibia, Reptilia, Aves, Mammalia), comparative anatomy of organ systems, ethology, and biogeography with detailed Nepal fauna coverage
  • Third Year: Cell Biology and Genetics (Zool. 301) + one elective specialization area (Ecology, Entomology, Parasitology, or Fish and Fisheries)
  • Fourth Year: Advanced electives in specialization + Project Work/Thesis (Zool. 406) — original research project in ecology, parasitology, entomology, or fisheries context

Career Opportunities for TU B.Sc. Zoology Graduates

  • Wildlife and conservation: Department of National Parks and Wildlife Conservation (DNPWC), WWF Nepal, ICIMOD, NTNC (National Trust for Nature Conservation), Snow Leopard Conservancy Nepal — wildlife monitoring, protected area management, species conservation, environmental impact assessment for development projects
  • Fisheries and aquaculture: Department of Fisheries, District Fisheries Development Offices, freshwater fisheries development along Nepal’s river systems — particularly hydropower reservoir fisheries and cold-water fish (trout — Himalayan rivers) and warm-water fish (Terai rivers and ponds)
  • Medical and veterinary parasitology: EDCD (Epidemiology and Disease Control Division), NHRC, veterinary hospitals — Plasmodium, Wuchereria, Fasciola, Taenia, Ascaris control programmes directly relevant to Nepal’s public health priorities
  • Entomology: vector control programmes (malaria, dengue, JE vector control — EDCD; WHO Nepal), agricultural pest management (Department of Agriculture), beekeeping development (national honey production and pollination services)
  • Academic and research: university-level teaching (requires M.Sc. and TU/TSC qualification); research positions at TU’s Central Department of Zoology, NAST, BPKIHS Zoology Department; international research partnerships (ICIMOD, WWF, IUCN Nepal)
  • Environmental impact assessment (EIA): zoological surveys for EIA reports required for infrastructure projects — hydropower plants, roads, airports — under Nepal’s Environment Protection Act; consultant zoologists in growing demand
  • Zoological museums and public education: Natural History Museum (NHM, Swayambhu); national parks interpretation centres; biodiversity documentation projects

Recommended Textbooks and References

Primary Textbooks (as listed in the official Zool. 101 syllabus)

  • Barnes, R.D. Invertebrate Zoology. Holt-Saunders International Edition (standard international reference — classification followed from this text as per official syllabus)
  • Barrington, E.J.W. Invertebrate Structure and Function. Nelson, London
  • Dhami, P.S. and Dhami, J.K. A Textbook of Zoology, Vol. I. Pradeep Publications, New Delhi (most widely used Nepali-accessible South Asian reference for TU B.Sc. First Year Zoology)
  • Verma, P.S. and Agrawal, V.K. A Textbook of Invertebrate Zoology. S. Chand and Co., New Delhi
  • Ruppert, E.E., Fox, R.S. and Barnes, R.D. Invertebrate Zoology: A Functional Evolutionary Approach. Thomson Brooks/Cole (comprehensive modern reference)
  • Hegner, R.W. and Engemann, J.G. Invertebrate Zoology. Macmillan, New York

Reference Books and Nepal-specific Resources

  • Shrestha, T.K. Wildlife of Nepal. Curriculum Development Centre, TU (essential Nepal fauna reference)
  • Shrestha, T.K. Herpetology of Nepal. Ms. Bimala Shrestha, Kathmandu (amphibians and reptiles of Nepal)
  • Jnawali, S.R. et al. (2011). The Status of Nepal’s Mammals: The National Red List Series. DNPWC, Kathmandu
  • Grimmett, R., Inskipp, C. and Inskipp, T. (2000). Birds of Nepal. Christopher Helm (standard Nepal ornithology reference)
  • Shah, K.B. and Tiwari, S. (2004). Herpetofauna of Nepal: A Conservation Companion. IUCN Nepal

Difference Between NEB Grade 12 and TU B.Sc. First Year Zoology

Students entering TU B.Sc. First Year Zoology from NEB Grade 12 Biology will encounter significant expansion in both depth and breadth. Grade 12 Biology covers: Evolutionary Biology, Faunal Diversity (classification of all major phyla up to class level, Paramecium and Plasmodium habits and life cycles, and earthworm and frog anatomy). TU Zool. 101 covers all of this — but at a fundamentally deeper level. Phylum classification is extended from surface-level listing to detailed morphological and evolutionary analysis of body plan, coelom, segmentation, and symmetry across all phyla. Individual organisms are studied with complete internal anatomy, cell-level structure, and detailed life cycle analysis requiring labelled diagrams from memory. Grade 12 introduces Plasmodium vivax at the habit and life cycle level; TU First Year requires detailed understanding of all stages (exoerythrocytic, erythrocytic, gametogony, sporogony in mosquito) at the cell and subcellular level, plus comparison of all four Plasmodium species. Protochordata (Hemichordata, Urochordata, Cephalochordata) — the most important group for understanding vertebrate origins — is not covered at all in the NEB curriculum, making it entirely new content in First Year.

Tips to Succeed in TU B.Sc. First Year Zoology

  • Master labelled diagrams as your highest priority: Zoology examinations at TU heavily reward accurate, clearly labelled diagrams. Every organism studied has at least one required diagram — life cycle, external morphology, internal anatomy, or cross-section. Practice drawing the following from memory until they are automatic: Paramecium (external morphology and organelles); conjugation cycle in Paramecium; Plasmodium vivax life cycle (human and mosquito phases); Sycon (canal system, LS); Obelia colony and medusa; Fasciola hepatica (whole mount); Taenia solium (scolex, mature proglottid, life cycle); Ascaris lumbricoides (male and female anatomy, TS); earthworm dissection (digestive, circulatory, reproductive systems); Periplaneta (nervous and digestive systems); Asterias (water vascular system); Amphioxus whole mount and cross-section; Balanoglossus body regions.
  • Study organisms in a consistent framework: For every organism, learn the following in order: Systematic position → Habit and habitat → External morphology → Internal anatomy (system by system) → Reproduction/Life cycle → Economic importance. Using this consistent framework prevents gaps and ensures complete answers in both short and long answer questions.
  • Prioritize Unit 3 (Non-Chordata I) — it carries the most teaching hours: At 55 hours, Non-Chordata I is the largest single unit and covers Porifera through Annelida in detail. Five specific organisms (Sycon, Obelia, Fasciola, Taenia, Ascaris, Pheretima) each require full internal anatomy, life cycle, and economic importance — these are the highest-frequency examination topics.
  • Understand the evolutionary significance of each phylum transition: TU Zoology examinations regularly ask questions linking structure to evolution — why the coelom was significant, what segmentation enabled, how Protochordata demonstrates vertebrate ancestry. Build these evolutionary arguments as you study each phylum rather than treating each as an isolated fact set.
  • The Protochordata unit (Unit 5) is unique and directly examined: Amphioxus (Branchiostoma) and Herdmania are organisms with no NEB equivalent. Their internal anatomy, chordate characters, and evolutionary significance are standard TU examination topics. The comparison of chordate characters across Balanoglossus, Herdmania, and Amphioxus is a classic table question.
  • Nepal-specific invertebrate content is examined: Distribution of Plasmodium vivax in Nepal’s Terai, Wuchereria and lymphatic filariasis in Nepal, Fasciola in Nepal’s livestock, Ascaris prevalence in Nepali children, invertebrate biodiversity of Nepal’s protected areas and rivers — all are stated in the syllabus and directly testable. Answers that include Nepal-specific examples consistently score higher than generic answers.
  • Attend all practical sessions and maintain a complete dissection notebook: The 50-mark Zool. 102 practical exam tests your ability to identify organisms, interpret slides, perform dissections, and draw from observation. Regular attendance and a well-organized, labelled practical notebook are prerequisites for a passing practical mark. The earthworm dissection and cockroach dissection are particularly important practical exam components.
  • Use Dhami and Dhami’s Textbook of Zoology Vol. I as your primary reference: This South Asian textbook is the most widely used reference for TU B.Sc. First Year Zoology across Nepal and covers all organisms in the syllabus in a format aligned with TU examination expectations. Supplement it with Barnes’s Invertebrate Zoology for classification and evolutionary context.

Frequently Asked Questions (FAQs)

What is the official full title and course code for TU B.Sc. First Year Zoology?

The official full title is Non-Chordata and Protochordata and the course code is B.Sc. Zool. 101 (theory, 100 marks, pass mark 35) and B.Sc. Zool. 102 (practical, 50 marks, pass mark 20). Both must be passed independently. Total lecture hours: 150 (theory) and 180 periods (practical).

How many units are in TU B.Sc. First Year Zoology?

Zool. 101 has 6 units: Unit 1 (Introduction to Animal Kingdom — 15 hours), Unit 2 (Protozoa — 20 hours), Unit 3 (Non-Chordata I: Porifera to Annelida — 55 hours, largest unit), Unit 4 (Non-Chordata II: Arthropoda, Mollusca, Echinodermata — 35 hours), Unit 5 (Protochordata — 25 hours), and Unit 6 (Evolutionary Relationships and Invertebrate Biodiversity of Nepal — 5 hours).

Which organism has the most detailed life cycle coverage in TU B.Sc. First Year Zoology?

Plasmodium vivax has the most detailed life cycle coverage — requiring students to know both the complete human phase (pre-erythrocytic schizogony, erythrocytic schizogony, gametogony) and the complete mosquito phase (fertilization, ookinete, oocyst, sporogony, sporozoites), along with comparisons of all four Plasmodium species, pathogenicity (malaria), and public health relevance in Nepal. The Taenia solium and Fasciola hepatica life cycles also require complete labelled diagrams.

Why is Amphioxus (Branchiostoma) so important in the First Year Zoology syllabus?

Amphioxus is the most chordate-like invertebrate — it possesses all three defining chordate characters (notochord extending to the anterior tip, dorsal hollow nerve cord, pharyngeal gill slits) throughout its entire life, unlike tunicates (which lose chordate characters in metamorphosis) or hemichordates (which lack a true notochord). Its study provides the clearest anatomical evidence for how the vertebrate body plan may have evolved from an invertebrate ancestor. The genome of Branchiostoma has been sequenced and confirms its position as the closest invertebrate relative of vertebrates — making it a crucial model organism in evolutionary biology.

What is the difference between Taenia solium and Taenia saginata?

Both are human intestinal tapeworms, but they differ in: (1) intermediate host — T. solium uses the pig (pork tapeworm), while T. saginata uses cattle (beef tapeworm); (2) scolex — T. solium has four suckers and a rostellum with two rows of hooks (armed tapeworm), while T. saginata has four suckers but no rostellum or hooks (unarmed tapeworm); (3) uterine branches — gravid proglottids of T. solium have fewer than 13 lateral branches, T. saginata has more than 15 — this is the key diagnostic difference; (4) cysticercosis — T. solium eggs are dangerous to humans (can develop into cysticerci in human brain — neurocysticercosis), while T. saginata does not cause cysticercosis in humans.

Where can I find Zoology notes and past papers for TU B.Sc. First Year?

You can find study resources on nneducation.com. The official Zool. 101 syllabus PDF is also embedded at the top of this page. For unit-wise notes and life cycle diagrams, microbenotes.com (authored by TU PhD microbiologist Dr. Sagar Aryal) provides comprehensive TU B.Sc. First Year Zoology notes. Past papers are available through EducateNepal (educatenepal.com) and the IoST TU official website (tuiost.edu.np). The Central Department of Zoology website (cdztu.edu.np) also provides the official syllabus PDFs.

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