Zoology Syllabus – UPSC Civil Services Mains Exam

The Zoology optional subject in the UPSC Civil Services Mains Exam is divided into two papers, with each paper carrying 250 marks. This brings the total marks allotted for the optional subject to 500.

Zoology Syllabus – UPSC Civil Services Mains Exam

Zoology Syllabus – UPSC Civil Services Mains Exam


1. Non-chordata and Chordata:

(a)  Classification and the relationship of various phyla up to subclasses: Acoelomate and Coelomate, Protostomes and Deuterostomes, Bilateria, and Radiata; Status of Protista, Parazoa, Onychophora, and Hemichordata; Symmetry.

(b)    Protozoa: Locomotion, nutrition, reproduction, sex; General features and life history of Paramaecium, Monocystis, Plasmodium, and Leishmania.

(c)   Porifera: Skeleton, canal system, and reproduction.


(d)    Cnidaria: Polymorphism, defensive structures, and their mechanism; coral reefs and their formation; metagenesis; general features and life history of Obelia and Aurelia.

(e)   Platyhelminthes: Parasitic adaptation; general features and life history of Fasciola and Taenia and their pathogenic symptoms.

(f)  Nemathelminthes: General features, life history, the parasitic adaptation of Ascaris, and Wuchereria.

(g)    Annelida: Coelom and metamerism; modes of life in polychaetes; general features and life history of Nereis,

earthworm and leach.

(h)    Arthropoda: Larval forms and parasitism in Crustacea; vision and respiration in arthropods (Prawn, cockroach, and scorpion); modification of mouthparts in insects (cockroach, mosquito, housefly, honey bee, and butterfly); metamorphosis in insect and its hormonal regulation, the social behavior of Apis and termites.

(i)   Mollusca: Feeding, respiration, locomotion, general features and life history of Lamellidens, Pila and Sepia, torsion and detorsion in gastropods.

(j)  Echinodermata: Feeding, respiration, locomotion, larval forms, general features, and life history of Asterias.

(k)  Protochordata: Origin of chordates; general features and life history of Branchiostoma and Herdmania.

(l)   Pisces: Respiration, locomotion, and migration.

(m)  Amphibia: Origin of tetrapods, parental care, paedomorphosis.

(n)  Reptilia: Origin of reptiles, skull types, the status of Sphenodon, and crocodiles.

(o)  Aves: Origin of birds, flight adaptation, migration.

(p)   Mammalia: Origin of mammals, dentition, general features of egg-laying mammals, pouched-mammals, aquatic mammals and primates, endocrine glands (pituitary, thyroid, parathyroid, adrenal, pancreas, gonads) and their interrelationships.

(q)    Comparative functional anatomy of various systems of vertebrates (integument and its derivatives, endoskeleton, locomotory organs, digestive system, respiratory system, circulatory system including heart and aortic arches, urinogenital system, brain and sense organs (eye and ear).

2. Ecology:

(a)  Biosphere: Concept of biosphere; biomes, Biogeochemical cycles, Human-induced changes in atmosphere including green house effect, ecological succession, biomes and ecotones, community ecology.

(b)   Concept of ecosystem; structure and function of ecosystem, types of ecosystem, ecological succession, ecological adaptation.

(c)   Population; characteristics, population dynamics, population stabilization.

(d)  Biodiversity and diversity conservation of natural resources.

(e)   Wildlife of India.

(f)  Remote sensing for sustainable development.

(g)   Environmental biodegradation, pollution, and its impact on the biosphere and its prevention.

3. Ethology:

(a)   Behaviour: Sensory filtering, responsiveness, sign stimuli, learning and memory, instinct, habituation, conditioning, imprinting.

(b)   Role of hormones in drive; the role of pheromones in alarm spreading; crypsis, predator detection, predator tactics, social hierarchies in primates, social organization in insects.

(c)     Orientation, navigation, homing, biological rhythms, biological clock, tidal, seasonal, and circadian rhythms.
(d)  Methods of studying animal behavior including sexual conflict, selfishness, kinship, and altruism.

4. Economic Zoology:

(a)  Apiculture, sericulture, lac culture, carp culture, pearl culture, prawn culture, vermiculture.

(b)    Major infectious and communicable diseases (malaria, filaria, tuberculosis, cholera, and AIDS) their vectors, pathogens, and prevention.

(c)   Cattle and livestock diseases, their pathogen (helminths), and vectors (ticks, mites, Tabanus, Stomoxys).

(d)  Pests of sugar cane (Pyrilla perpusiella) oil seed (Achaea janata) and rice (Sitophilus oryzae).

(e)   Transgenic animals.

(f)  Medical biotechnology, human genetic disease, and genetic counseling, gene therapy.

(g)   Forensic biotechnology.

5. Biostatistics:

Designing of experiments; null hypothesis; correlation, regression, distribution, and measure of central tendency, chi-square, student-test, F-test (one-way & two-way F-test).

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6. Instrumentation Methods:

(a)   Spectrophotometer, phase contrast, and fluorescence microscopy, radioactive tracer, ultracentrifuge, gel electrophoresis, PCR, ELISA, FISH, and chromosome painting.

(b)  Electron microscopy (TEM, SEM).


1. Cell Biology:

(a) Structure and function of the cell and its organelles (nucleus, plasma membrane, mitochondria, Golgi bodies, endoplasmic reticulum, ribosomes, and lysosomes), cell division (mitosis and meiosis), mitotic spindle and mitotic apparatus, chromosome movements, chromosome type polytene and lampbrush, organization of chromatin, heterochromatin, Cell cycle regulation.

(b) Nucleic acid topology, DNA motif, DNA replication, transcription, RNA processing, translation, protein foldings, and transport.

2. Genetics:

(a)  Modern concept of the gene, split gene, genetic regulation, genetic code.

(b)  Sex chromosomes and their evolution, sex determination in Drosophila and man.

(c)   Mendel’s laws of inheritance, recombination, linkage, multiple alleles, genetics of blood groups, pedigree analysis, hereditary diseases in man.

(d)  Mutations and mutagenesis.

(e)    Recombinant DNA technology; plasmid, cosmid, artificial chromosomes as vectors, transgenic, DNA cloning, and whole animal cloning (principles and methods).

(f)  Gene regulation and expression in prokaryotes and eukaryotes.

(g)   Signal molecules, cell death, defects in the signaling pathway, and consequences.

(h)   RFLP, RAPD, and AFLP and application of RFLP in DNA fingerprinting, ribozyme technologies, human genome project, genomics, and proteomics.

3. Evolution:

(a)  Theories of origin of life.

(b)   Theories of evolution; Natural selection, the role of mutations in evolution, evolutionary patterns, molecular drive, mimicry, variation, isolation, and speciation.
(c)   Evolution of horse, elephant, and man using fossil data.

(d)  Hardy-Weinberg Law.

(e)   Continental drift and distribution of animals.

4. Systematics:

Zoological nomenclature, international code, cladistics, molecular taxonomy, and biodiversity.

5. Biochemistry:

(a) Structure and role of carbohydrates, fats, fatty acids and cholesterol, proteins and amino-acids, nucleic acids. Bioenergetics.

b) Glycolysis and Kreb cycle, oxidation and reduction, oxidative phosphorylation, energy conservation and release, ATP cycle, cyclic AMP – its structure and role.

(c)   Hormone classification (steroid and peptide hormones), biosynthesis, and functions.

(d)  Enzymes types and mechanisms of action.

(e)   Vitamins and co-enzymes

(f)  Immunoglobulin and immunity.

6. Physiology (with special reference to mammals):

(a)   Composition and constituents of blood; blood groups and Rh factor in man, factors and mechanism of coagulation, iron metabolism, acid-base balance, thermo-regulation, anticoagulants.

(b)  Haemoglobin: Composition, types and role in transport of oxygen and carbon dioxide.

(c)   Digestion and absorption: Role of salivary glands, liver, pancreas, and intestinal glands.

(d)  Excretion: nephron and regulation of urine formation; osmoregulation and excretory product.

(e)   Muscles: Types, mechanism of contraction of skeletal muscles, effects of exercise on muscles.

(f)  Neuron: nerve impulse – its conduction and synaptic transmission, neurotransmitters.

(g)   Vision, hearing, and olfaction in man.

(h)  Physiology of reproduction, puberty, and menopause in humans.

7. Developmental Biology:

(a)   Gametogenesis; spermatogenesis, the composition of semen, in vitro and in vivo capacitation of mammalian sperm, Oogenesis, totipotency; fertilization, morphogenesis, and morphogen, blastogenesis, the establishment of body axes formation, fate map, Gastrulation in frog and chick; genes in development in chick, homeotic genes, development of eye and heart, placenta in mammals.

(b)   Cell lineage, cell-to-cell interaction, Genetic and induced teratogenesis, the role of thyroxine in control of metamorphosis in amphibia, paedogenesis, and neoteny, cell death, aging.

(c)   Developmental genes in man, in vitro fertilization and embryo transfer, cloning.

(d)  Stem cells: Sources, types, and their use in human welfare.

(e)   Biogenetic law.

Useful LINKS:

  1. Useful UPSC Civil Services Books
  2. IAS Study Materials for Online Preparation
  3.  UPSC Question Papers
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