UPSC Zoology Optional Mains Syllabus: A Comprehensive Guide (Paper I & II)

Zoology is a favored optional subject for many UPSC aspirants with a background in life sciences, medicine, or veterinary sciences. It is a scientific and analytical subject, offering clarity in preparation due to its defined syllabus. This blog breaks down the Zoology Optional syllabus for UPSC Mains into Paper I and Paper II, based on the latest UPSC notification, with detailed descriptions for better understanding and strategic preparation.

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Paper I: Non-Chordata, Chordata & Cell Biology

Section A: Non-Chordata and Chordata

1. Classification and Relationship of Major Animal Phyla

• General and comparative account of the following:
• Coelom: Acoelomate, pseudocoelomate, coelomate conditions
• Symmetry: Radial, bilateral, and asymmetry
• Segmentation and Metamerism
• Basis of classification (developmental and molecular)
• Evolutionary relationship among phyla based on body plan and embryology

2. Protozoa to Hemichordata

• Protozoa:
• Locomotion, reproduction, and parasitic protozoans (e.g., Plasmodium)
• Porifera:
• Canal system, spicules, and their significance
• Coelenterata:
• Polymorphism, coral reefs, metagenesis
• Platyhelminthes:
• Parasitic adaptations, life cycle of Fasciola and Taenia
• Nematoda:
• Ascaris and filarial worm, their impact on human health
• Annelida:
• Coelom, segmentation, nephridia, and locomotion
• Arthropoda:
• Larval forms, metamorphosis, and economic importance (e.g., honey bee, silkworm)
• Mollusca:
• Torsion and detorsion in gastropods, pearls
• Echinodermata:
• Water vascular system, larval forms
• Hemichordata:
• Affinities with chordates and non-chordates

3. Chordata

• General characters and classification of Chordates
• Comparative anatomy of the following:
• Integumentary System
• Skeletal System
• Digestive System
• Respiratory System
• Circulatory System
• Excretory System
• Reproductive System
• Adaptive features in:
• Fishes (e.g., air bladder, scales)
• Amphibians (e.g., dual mode of life)
• Reptiles (e.g., excretion, thermoregulation)
• Birds (e.g., flight adaptation)
• Mammals (e.g., hair, mammary glands)

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Section B: Cell Biology and Genetics

1. Cell Structure and Function

• Prokaryotic and eukaryotic cells
• Ultrastructure of:
• Plasma membrane
• Mitochondria
• Golgi apparatus
• Endoplasmic reticulum
• Lysosomes
• Ribosomes
• Cilia and flagella
• Nucleus:
• Nuclear membrane, nucleolus, and chromosomes

2. Cell Cycle and Cell Division

• Mitosis and meiosis – stages and significance
• Regulation of cell cycle
• Apoptosis – programmed cell death

3. Chromosomes and Gene Expression

• Chromosome structure – euchromatin and heterochromatin
• Types of chromosomes – sex chromosomes, autosomes
• DNA replication, transcription, and translation
• Gene regulation in prokaryotes and eukaryotes (e.g., operon model)
• Mutations – types and effects

4. Molecular Genetics and Techniques

• Genetic code, gene concept
• Recombinant DNA technology
• PCR, blotting techniques (Southern, Northern, Western)
• Cloning vectors, gene therapy basics

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Paper II: Physiology, Developmental Biology, Ecology, and Applied Zoology

Section A: Physiology and Biochemistry

1. Physiology of Animals (with special reference to mammals)

• Blood and Circulation:
• Composition, blood groups, coagulation, heart physiology
• Respiration:
• Mechanism of gas exchange, oxygen transport
• Excretion:
• Structure and function of kidney, urine formation
• Nervous System:
• Neurons, impulse conduction, reflex action
• Endocrinology:
• Hormones of pituitary, thyroid, adrenal, pancreas
• Feedback mechanism in hormone regulation
• Muscle Physiology:
• Types of muscles, mechanism of contraction
• Reproduction:
• Gametogenesis, menstrual cycle, fertilization

2. Biochemistry

• Carbohydrates, proteins, lipids – structure, metabolism
• Enzymes:
• Classification, kinetics, factors affecting activity
• Vitamins and coenzymes
• Metabolic pathways:
• Glycolysis, Krebs cycle, oxidative phosphorylation

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Section B: Developmental Biology, Ecology & Applied Zoology

1. Embryology and Developmental Biology

• Gametogenesis and fertilization
• Types of eggs and patterns of cleavage
• Blastulation and gastrulation
• Development of vertebrates: Frog and Chick
• Extra-embryonic membranes and placenta
• Organizer concept and morphogen gradients
• Regeneration, metamorphosis, and teratogenesis
• Stem cells and assisted reproductive technologies (IVF, cloning)

2. Ecology and Ethology

• Ecosystems: Structure and energy flow, food chain/web, ecological pyramids
• Population ecology: Growth models, survivorship curves
• Community ecology: Succession, species diversity
• Biodiversity:
• Conservation strategies, wildlife protection acts
• Ethology:
• Animal behavior, communication, learning, and social organization
• Role of hormones in behavior

3. Applied Zoology

• Economic Zoology:
• Apiculture, sericulture, lac culture, aquaculture, vermiculture
• Pest control:
• Biological and integrated pest management
• Animal Husbandry:
• Dairy and poultry farming, livestock breeding
• Zoonotic Diseases:
• Causes, transmission, and control (e.g., rabies, anthrax)
• Wildlife conservation:
• Endangered species, national parks, sanctuaries
• Forensic Zoology:
• Role of insects and animals in crime detection

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Final Thoughts: Why Choose Zoology?

Zoology as an optional is scientific and factual, with limited scope for subjective interpretation. It offers:

• Clear and defined syllabus
• Overlap with GS papers in ecology and environment
• Good scoring potential with diagrams and illustrations
• Especially helpful for students from zoology, medical, or life science backgrounds