How to prepare for Zoology optional: strategy, Tips & Syllabus?

“We commonly say in the trade that the most dangerous animal in a zoo is Man.”
— Yann Martel

But what If there is an optional—an optional that is defined as the scientific study of animals?

It’s an Intriguing Subject, right? But, let’s see the ground reality.

UPSC organizes IAS Examination in three stages – Prelims, Mains and Interview. The combination of all the marks from these three stages decides your ranking in the final list. One must select his optional with a great care and follow the right strategies to execute his preparation. You know that, but what else do we have here?

Here is a strategy of Zoology optional by our subject matter experts by keeping UPSC Mains Examination as their focal point. We are also adding some tips that will help you crack this subject with much ease. Adding to that, we are also compiling a list of mandate books for Zoology optional.

First thing First, Know your Optional Syllabus. We are attaching it at the end of the article. Kindly refer it, before you start reading the article. Why? One must understand what he is getting into—before he ever gets into it.

If you look at the syllabus of Zoology Optional, you would know that it’s demanding in both terms; your time and efforts. Looking at its lengthy syllabus, aspirants must acknowledge that there are many things to cover in limited time. Furthermore, understanding the syllabus will also help you to differentiate between what to study what not to study.

What makes Zoology a scoring subject?

Being a science subject, and even after the scaling imposed on it by UPSC—Zoology emerged as an optional in which aspirants could score well. Why?

It’s a science-based subject.

Zoology is mostly preferred by the students from Medicine, Life Science, Forestry, Agriculture, Zoology or Botany background. Students from the other background, especially the non-science background might find it as a challenging task. For scoring well into this subject—candidates must indulge in the extensive reading of the syllabus.

You must know that scoring in any optional subject is not an art of choosing an easy subject, but putting in work—shed your sweat and blood on your chosen subject. That’s the way to go for Zoology—that’s the way to go for any subject for that matter.

You must get through the basic concepts and facts of the syllabus, followed by analyzing the previous year question papers. You should also try to analyze the pattern of UPSC and the variety of questions it asks from the kind of topics—this conceptual clarity will help you answer twisted and indirect questions.

Extensive Reading Habit

Zoology, being a vast optional subject includes diverse elements. The subject demands intense reading sessions to understand its complex concepts and sub-topics. There are several books that come under its syllabus—but one must pick only the best ones—ones that are still important.

Handmade Short Notes

Your handmade notes are your biggest assets and an essential part of your UPSC preparation. Zoology is a subject that’s loaded with abundant figure and information—it’s highly advisable to turn it into concise short—crispy notes. This will ensure that your answers in UPSC Mains Exam are balance and absolute—covering all the major points of the syllabus.

Writing Your Answers

  • Syllabus of Zoology includes almost entire animal kingdom which gives one a wide expression of their ideas. One must not write answers under the flow of his own instincts but stick to be concise and relatable to the topic that’s asked.
  • Diagrams need not be perfect but an average—neatly drawn diagram would solve the purpose, according to the UPSC.
  • Aspirants must frame their answers with necessary diagrams and concentrate on keeping their answers to the point and precise. We couldn’t force it enough to be precise.
  • One must learn to formulate brief and brilliant introductions for making a great impression on the evaluator.
  • Terminologies must be properly cited as it contains scientific terms and words. Also, use diagrams and flowcharts to express your answers in a finer way.
  • Go through the previous year question papers and analyze the kind of questions UPSC asks and make a list of questions asked from each Phylum. This division would make a lengthy portion short and give you the confidence for completing the syllabus in a shorter period.

Analyze the important topics in Paper I and Paper II

As stated earlier in the article, analyze the previous year question papers to try to grasp the methodology used by UPSC. Also, try to understand the pattern and the type of the questions generally picked by the commission. Through the mentioned strategy, single out the most important topics from both; Paper I and Paper II.

In accordance with our Subject Matter Experts—we’re citing some important topics in compliance with Previous Year question papers:

  • Economic Zoology
  • Physiology and Biochemistry
  • Genetics
  • Developmental Biology
  • Vertebrate Zoology with comparative anatomy
  • Invertebrates
  • Ecology
  • Biostatistics and Bio-instrumentation
  • Evolution

Tips for Paper 1 & Paper II

General essays must be your priority when it comes to Paper I. You must cover all the theories and correlate them to an evolutionary viewpoint. Whilst studying Economic Zoology, one must focus on topics related to the recent developments in India and relate their answers accordingly.

For Zoology Paper II, it’s significant to express what we know and relate it to how we know it. One must also describe what they know with respect to the human aspects—to connect how the study of animals impacts our understanding of the world around us.

Recommended Books

ONE MUST START HIS PREPARATION with easy and basic books—to build the foundation first and then move to the detailed studies. The starting approach must be to get the conceptual clarity around the scientific jargons. One must know that the detailed reference books must only come post to the conceptual clarity and after some basic reading. Its vast syllabus demands several books. Here are our top recommendations by our Subject Matter Experts;

  • A Dictionary of Entomology – Leftwich
  • Embryology – Balinsky, A.K. Berry, Vir Bala Rastogi
  • General zoology: Tracy Irwin Storer
  • Ecology – P.D. Sharma, Odum, Vir Bala Rastogi and M.S. Jayaraj, Kotpal and Bali
  • Evolution – Vir Bala Rastogi
  • Organic evolution – Veer Bala Rastogi
  • Cell and Molecular Biology – De Robertis, C.B. Powar
  • Invertebrates – R.L. Kotpal, Nigam, Jordan
  • Vertebrates – R.L. Kotpal, Nigam, Jordan and Varma
  • Comparative anatomy of vertebrate zoology – Kent
  • Robert L. Usinger
  • Economic Zoology – Shukla and Upadhaya, Kotpal Series, Kotpal- Khetrapal – Agarwal
  • Ethology – Reena Mathur, Magazines like Science Reporter, Nature etc.
  • Biochemistry – Harper, Lehninger, Stryer, Rao
  • Genetics – P.K. Gupta, Gardner, Ahluwalia, Vir Bala Rastogi
  • Physiology – H.R. Singh
  • Animal physiology – H.R. Singh, Vander

Zoology Syllabus

UPSC Examination has Zoology as one of the Optional Subjects with 2 papers; Paper I & Paper II. Each paper is of 250 marks with a total summing up to 500 marks.


1.Non-Chordata and Chordata:

(a) Classification and 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 mouth parts in insects (cockroach, mosquito, housefly, honey bee and butterfly); metamorphosis in insect and its hormonal regulation, 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, the circulatory system including heart and aortic arches, urino-genital system, brain and sense organs (eye and ear).

  1. Ecology:

(a) Biosphere: Concept of the biosphere; biomes, Biogeochemical cycles, Human-induced changes in the atmosphere including the greenhouse 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.

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

(b) Role of hormones in the 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.

  1. 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) oilseed (Achaea Janata) and rice (Sitophilus oryzae).

(e) Transgenic animals.

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

(g) Forensic biotechnology.

  1. 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).

  1. Instrumentation Methods:

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

(b) Electron microscopy (TEM, SEM).

 Paper II

  1. Cell Biology:

(a) Structure and function of 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.

  1. Genetics:

(a) The 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 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.

  1. Systematics: Zoological nomenclature, international code, cladistics, molecular taxonomy, and biodiversity.
  1. Biochemistry:

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

  1. 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.

  1. 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) Hemoglobin: Composition, types, and role in the 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.

  1. Developmental Biology:

(a) Gametogenesis; spermatogenesis, composition of semen, in vitro and in vivo capacitation of mammalian sperm, Oogenesis, totipotency; fertilization, morphogenesis and morphogen, blastogenesis, establishment of body axes formation, fate map, gesticulation 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.

Good Luck



  1. I m looking for study material for Orissa state public services for prelims and mains
    The optional subjects are geography and zoology
    Requested to provide information on study materials and fees charged for postal courses.


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