Zoology — Revision Checklist
All 8 Zoology units broken into checkable items, prioritised by TGBIE exam weight.
Unit VII: Periplaneta americana — High Weight
High- External morphology: head (mouthparts, compound eyes, antennae), thorax (pro/meso/meta + wings), abdomen (10 segments, cerci)
- Digestive system: mouth → pharynx → oesophagus → crop → gizzard → mesenteron → ileum → colon → rectum → anus; Malpighian tubules at junction of stomach and ileum
- Nervous system: supra-oesophageal ganglion (brain) + sub-oesophageal ganglion + ventral nerve cord + 6 abdominal ganglia
- Ommatidium: structure of compound eye unit — corneal lens, crystalline cone, rhabdom, retinal cells, pigment cells
- Reproductive system (male): testes, vas deferens, seminal vesicle, mushroom gland, ejaculatory duct
- Draw all 5 system diagrams with labels — these are the most frequently drawn diagrams in Zoology
Unit VIII: Ecology — High Weight
High- Ecosystem components: producers, consumers, decomposers, abiotic factors
- Food chain vs food web: food chain is linear; food web is interconnected
- Ecological pyramids: number (may be inverted in parasitic chain), biomass (inverted in aquatic), energy (always upright)
- Carbon cycle: photosynthesis absorbs CO₂; respiration, decomposition, combustion release CO₂
- Nitrogen cycle: N₂ fixation (bacteria) → nitrification → assimilation → ammonification → denitrification
- Population growth: J-curve (exponential), S-curve (logistic/sigmoid); birth rate, death rate, natality, mortality
- Environmental issues: acid rain, water pollution, soil pollution, ozone depletion, global warming — causes and effects
Unit III & IV: Animal Diversity — High Weight
High- Phylum Porifera: pore-bearing, asymmetrical, cellular organisation, no true tissues; e.g., Sycon, Spongilla
- Phylum Cnidaria: radial symmetry, diploblastic, cnidocytes, coelenteron; e.g., Hydra, Obelia
- Phylum Platyhelminthes: bilateral, triploblastic, acoelomate, flat body; e.g., Taenia (tapeworm)
- Phylum Annelida: segmented, coelomate, setae; e.g., earthworm (Pheretima)
- Phylum Arthropoda: jointed appendages, exoskeleton, open circulatory system; largest phylum
- Chordates: pharyngeal slits, notochord, dorsal hollow nerve cord, post-anal tail
- Class Amphibia: moist skin, gills in larva → lungs in adult, ectothermic; e.g., frog
- Class Mammalia: hair/fur, mammary glands, 4-chambered heart, warm-blooded
Unit VI: Biology & Human Welfare — Medium Weight
Medium- Plasmodium vivax: Anopheles mosquito vector; sporozoite → liver → merozoites → RBCs; gametocytes infect mosquito
- Ascaris: roundworm, soil-transmitted; eggs ingested → larva migrates → adult in small intestine
- Wuchereria bancrofti: filarial worm; causes elephantiasis; Culex mosquito vector
- Typhoid: Salmonella typhi; contaminated water/food; treated with chloramphenicol
- Tobacco: nicotine is addictive; causes lung cancer, cardiovascular disease
- Alcohol: affects liver → cirrhosis; affects brain → loss of coordination
Unit I, II & V — Medium Weight
Medium- Biodiversity: genetic (within species), species (between species), ecosystem (community level); IUCN categories: extinct, endangered, vulnerable
- Levels of organisation: cellular → tissue → organ → organ system → organism
- Coelom: absent in acoelomates (Platyhelminthes), false in pseudocoelomates (Nematoda), true in eucoelomates
- Protozoan locomotion: pseudopodia (Amoeba), flagella (Euglena), cilia (Paramecium)
- Binary fission: transverse in Paramecium, longitudinal in Euglena