BSc Zoology 3rd Semester Notes PDF ๐
Master your Zoology Hons. third semester at Delhi University (DU). Download complete unit-wise theory PDFs, study materials, and fully solved previous year questions (PYQs).
๐ DU Semester 3 Syllabus Overview
Official DU SyllabusThe third semester of BSc Zoology (Hons.) introduces students to chordates, biochemistry, and human physiology. The core subjects include:
Unit I: Introduction to Chordates
Topics covered: General characteristics and outline classification.
Unit II: Protochordata
Topics covered: General characteristics of Hemichordata, Urochordata and Cephalochordata; Study of Tornaria and Ascidian larval forms in protochordates.
Unit III: Origin of Chordates
Topics covered: Theories of Origin of chordates with detailed concept of Dipleurula and the Echinoderm theory.
Unit IV: Agnatha
Topics covered: General characteristics and classification of cyclostomes up to Class.
Unit V: Pisces
Topics covered: General characteristics of Chondrichthyes and Osteichthyes; Classification up to order; Osmoregulation; Swim bladder in fishes.
Unit VI: Amphibia
Topics covered: General characteristics and classification up to order; Origin of Tetrapods (Evolution of terrestrial ectotherms); Parental care in Amphibians.
Unit VII: Reptilia
Topics covered: General characteristics and classification up to order; Affinities and evolutionary significance of Sphenodon; Poison apparatus and biting mechanism in snakes.
Unit VIII: Aves
Topics covered: General characteristics and classification up to order; Flight adaptations; Migration in birds.
Unit IX: Mammalia
Topics covered: General characteristics and classification up to order; Adaptive radiation with reference to locomotory appendages of mammalia.
Unit X: Zoogeography
Topics covered: Zoogeographical realms, Plate tectonics and Continental drift theory.
Most important questions and PYQs included of Chordates semester 3 DU
All the PYQs of Introduction Of Chordates semester 3 DU
Unit I: Carbohydrate Metabolism
Topics covered: Glycolysis, Citric acid cycle, Phosphate pentose pathway, Gluconeogenesis, Glycogenolysis and Glycogenesis.
Unit II: Lipid Metabolism
Topics covered: ฮฒ-oxidation and omega-oxidation of saturated fatty acids with even number of carbon atoms; Biosynthesis of palmitic acid; Ketogenesis.
Unit III: Protein Metabolism
Topics covered: Catabolism of amino acids: Transamination, Deamination, Urea cycle.
Unit IV: Oxidative Phosphorylation
Topics covered: Redox systems; review of mitochondrial respiratory chain: electron carriers, sites of ATP production, Oxidative phosphorylation; Chemiosmotic hypothesis, mitochondrial shuttle system.
Unit V: Liver as a Major Metabolic Hub
Topics covered: Inter-connection of glucose-6-phosphate, pyruvate and acetyl-CoA; fates of amino acids, fatty acids and glucose in liver cells; cascade of metabolic events in fasting and starvation.
Most important questions and PYQs included for Biochemistry semester 3 DU
DU PYQs for Biochemistry exams.
Unit I: Physiology of Digestion
Topics covered: Overview of gastrointestinal tract and its associated glands; digestion; Absorption of carbohydrates, lipids, proteins; Hormonal control of secretion of enzymes in gastrointestinal tract.
Unit II: Blood
Topics covered: Structure and functions of haemoglobin; Blood clotting system, Fibrinolytic system.
Unit III: Physiology of Heart
Topics covered: Structure of heart; Coronary circulation; Origin and conduction of cardiac impulses; Cardiac cycle; Cardiac output and its regulation; nervous and chemical regulation of heart rate.
Unit IV: Physiology of Respiration
Topics covered: Overview of respiratory system; Mechanism of respiration, Respiratory volumes and capacities; Transport of oxygen and carbon dioxide in blood; regulation of respiration.
Unit V: Renal Physiology
Topics covered: Structure of kidney and its functional unit; Mechanism of urine formation; Regulation of water balance; Regulation of acid-base balance.
Quick revision notes and Most important questions for Human Physiology semester 3 DU.
DU PYQs for Human Physiology semester 3 exams.
Your Blueprint for 3rd Semester Zoology Success
Transitioning deeper into the Delhi University core curriculum means tackling complex biological systems. We designed these resources to cut out the noise and give you exactly what you need to score a 9+ CGPA.
Targeted Study Material
Don't waste time summarizing 500-page textbooks. Our bsc zoology 3rd semester notes pdf files condense Diversity of Chordates, Biochemistry, and Human Physiology into highly readable, exam-focused formats.
Complex Pathways Simplified
Subjects like Biochemistry and Human Physiology can feel overwhelming. We've structured metabolic pathways and physiological systems cleanly, ensuring you memorize steps conceptually, not blindly.
The Power of PYQs
DU exams heavily repeat past formats. By studying our curated list of delhi university exam prep questions and PYQs, you will know exactly what the professors are going to ask before you even enter the hall.
๐ How to Score 9+ CGPA in BSc Zoology Hons
Scoring a 9+ CGPA in BSc Zoology Hons at Delhi University isn't really about reading more. It's about studying in the right order. Here's the method that actually works for semester exams, based on how DU papers are usually set.
Start with the PYQs, not the notes
Before opening any unit, go through the previous year questions (PYQs) already available on this page. This shows you exactly which topics get asked again and again in the Zoology exam, so you know where to put your first round of effort instead of studying every unit with equal priority.
Download the notes and study that topic properly
Once you know which topics matter most, download the unit-wise notes for that topic and actually read through it instead of jumping straight to definitions. Understanding a concept once makes it far easier to recall in the exam than memorising it without context.
Practice every diagram and flowchart
Zoology answers carry real weightage for labelled diagrams and flowcharts, things like life cycles, cell structures, and biochemical pathways. Sketch these out by hand a few times rather than just looking at them. A clean, correctly labelled diagram often earns marks even when the written explanation is average.
Go back to the PYQs and test yourself
After finishing a topic, return to the same previous year questions and try answering them from memory, without your notes open. This is much closer to actual exam conditions than passive revision, and it tells you honestly which parts you still need to revisit.
Write full answers under a timer, at least once
For long-answer questions, practice writing a complete answer within a set time limit before the actual exam. Knowing the content isn't the same as being able to structure and finish it in time, so this step matters more than most students expect.
Finish one topic fully before moving to the next
Repeat this PYQ, notes, diagram, and self-test cycle one topic at a time across every unit rather than skimming all units once. It keeps each topic genuinely exam-ready instead of leaving several topics half-prepared right before the semester exam.
โ Frequently Asked Questions
The third semester of BSc Zoology at Delhi University includes Diversity of Chordates, Biochemistry: Metabolic Processes, and Human Physiology: Life Sustaining Systems.
Yes. These notes are structured exactly according to the latest Delhi University BSc Zoology (Hons.) syllabus and include unit-wise explanations, diagrams, and important questions.
Yes. The notes comprehensively cover all major pathways including Glycolysis, Krebs Cycle, Beta-oxidation, and Oxidative Phosphorylation required for the exams.
Yes! Important previous year questions (PYQs) from past Delhi University Zoology exams are integrated into the units for download for better exam preparation.
If you have any doubts related to the notes, BSc Zoology syllabus or any other general doubt, you can reach out via Email at sayheyshubh@gmail.com or Instagram @sayheyshubh. You can also join our Telegram community!