BZYCT-133 Solved Question Paper June 2026 gives complete, exam-length answers to all 25 answerable items of the IGNOU June 2026 Term-End Examination paper in Comparative Anatomy and Developmental Biology of Vertebrates. Two answers are open on this page — Q3 from comparative anatomy and Q5(a) from developmental biology; the other 23 come in the full file on WhatsApp 9899436384.
BZYCT-133 Comparative Anatomy and Developmental Biology of Vertebrates key facts for the June 2026 solved question paper
- Course code: BZYCT-133
- Course title: Comparative Anatomy and Developmental Biology of Vertebrates
- Programmes: Bachelor of Science (General), BSCG, with zoology as a discipline; also examined for Bachelor of Science (Multidisciplinary), BSCM — both are printed on the June 2026 paper header
- Credits: 4, theory; taken with its 2-credit companion lab BZYCL-134, so the pair comes to 6 credits
- Blocks and units: [VERIFY: IGNOU block and unit numbers for BZYCT-133 could not be confirmed from an official source. The syllabus table below groups the paper by examined area instead of guessing unit numbers]
- Maximum marks: 50 (Term-End Examination)
- Duration: 2 hours
- Structure of the June 2026 paper: Question 1 compulsory for 10 marks, then any four of Questions 2 to 7 at 10 marks each
- Answerable items: 25 — Question 1 alone holds 12 of them, and Question 7 offers four short notes of which you attempt two
- Mark values used: 0.5, 1, 5 and 10 — the half-mark fill-in-the-blanks in Q1(a) are the smallest unit on any paper we have analysed
- Diagrams: labelled figures are explicitly asked for in Q2(a) and Q6(b), and expected wherever they help
- Samples shown on this page: 2 (Q3 on kidney succession, Q5(a) on embryonic induction)
- Questions in the paid file: all 25 items answered, including all four short-note options in Question 7
What the BZYCT-133 solved question paper June 2026 covers
BZYCT-133 is a zoology course of IGNOU's Bachelor of Science (General) that compares organ systems across fishes, amphibians, reptiles, birds and mammals, and then follows a vertebrate embryo from the egg to its organs.
The June 2026 paper carried 50 marks in two hours. It mixed comparative anatomy — frog lungs, fish aortic arches, the avian pituitary — with developmental biology — gastrulation, mammalian oogenesis, the membranes around the chick embryo. Our file answers every part of it, including all four short-note options in Question 7.
Three things about this paper change how you should plan for it. First, it is a 50-mark paper built from 25 separate items, and Question 1 alone holds twelve of them for ten marks — which makes it the one part of the paper where extra time buys you nothing. Section 4 works out the time plan that follows. Second, the two halves of the course are not offered equally: section 5 shows that comparative anatomy alone could have answered this paper and developmental biology alone could not. Third, we have corrected the answer lengths this page originally carried, because the figures were about double what two hours allows once you account for the diagrams.
If you need more practice papers from other sessions, our IGNOU Previous Year Question Paper collection sits alongside this file.
BZYCT-133 sample answers: kidney succession and embryonic induction
Two complete answers are shown below — Question 3 from comparative anatomy and Question 5(a) from developmental biology — so you can judge both halves of the course before ordering. Both were written by our zoology team for this page, because the official IGNOU paper prints questions only. The remaining 23 items are listed after them as question text alone.
Question 3 Any 4 of Q2 to Q7 Excretory system 10 marks diagram expected The only undivided 10-mark question on the paper
3. Describe the succession of kidneys in vertebrates. 10
Introduction. Every vertebrate kidney develops from the intermediate mesoderm, a strip of tissue called the nephrotome or nephric ridge that lies between the somites and the lateral plate mesoderm. In evolution, and again inside a single embryo, three kidneys appear one after another from front to back: the pronephros, the mesonephros and the metanephros. The replacement of one kidney by the next is called the succession of kidneys.
Archinephros, the ancestral plan. The earliest vertebrate kidney is thought to have been an archinephros or holonephros. It ran along the whole length of the body cavity with one pair of tubules in each body segment. Each tubule opened into the coelom by a ciliated funnel, the nephrostome, and drained into a common archinephric duct. A kidney close to this plan is described in the larvae of hagfishes and of caecilians.
Pronephros, the head kidney. This is the first kidney to form, from the most anterior nephrotomes just behind the head. It has only a few tubules, each with a nephrostome opening into the coelom. Blood is filtered by an external glomerulus, or glomus, that hangs into the coelom, and the fluid is swept into the tubules. The tubules join a pronephric duct that grows backwards to open into the cloaca.
The pronephros is the working kidney of larval fishes and of the frog tadpole, and it remains functional in adult hagfishes and a few bony fishes. In reptiles, birds and mammals it appears only briefly in the embryo, does little or no work, and then degenerates. Its duct, however, is kept and reused by the next kidney.
Mesonephros, the middle kidney. As the pronephros degenerates, a second kidney forms behind it from the middle nephrotomes. Its tubules are more numerous and lose their strict one-per-segment arrangement. Each tubule now has a cup-shaped Bowman's capsule around an internal glomerulus, forming a true renal corpuscle, and nephrostomes become reduced or are lost. The old pronephric duct now serves this kidney and is called the mesonephric or Wolffian duct.
The mesonephros is the functional kidney of embryonic reptiles, birds and mammals, where it works only until the final kidney takes over. In adult fishes and amphibians the kidney that extends back from this region is often called an opisthonephros. In males, some anterior mesonephric tubules join the testis as vasa efferentia and the Wolffian duct becomes the sperm duct, so the excretory and reproductive systems become linked.
Metanephros, the hind kidney. This is the permanent kidney of amniotes — reptiles, birds and mammals. It develops from two sources. A ureteric bud grows out from the hind end of the Wolffian duct and forms the ureter, renal pelvis and collecting tubules, while the surrounding metanephric mesoderm, or blastema, forms the nephrons. The nephrons have no nephrostomes and no link with the coelom.
A metanephric kidney has a very large number of nephrons, about a million in each human kidney. Mammals, and birds in part of their nephrons, add a loop of Henle, which lets them produce urine more concentrated than blood. This saving of water is an important adaptation to life on land.
| Feature | Pronephros | Mesonephros | Metanephros |
|---|---|---|---|
| Position | Most anterior | Middle of the nephric ridge | Most posterior |
| Nephrostome | Present, opens into coelom | Reduced or absent | Absent |
| Glomerulus | External glomus | Internal, in Bowman's capsule | Internal, many renal corpuscles |
| Duct | Pronephric duct | Wolffian (mesonephric) duct | Ureter, from the ureteric bud |
| Functional in | Larval fishes and tadpoles; adult hagfishes | Adult fishes and amphibians; amniote embryos | Adult reptiles, birds and mammals |
Significance. The succession shows a steady trend: more nephrons, better filtration through internal glomeruli, loss of the open link with the coelom, and a separate ureter. The ducts of the earlier kidneys are not wasted but taken over by the reproductive system.
Two things decide the mark on this question. First, draw the nephric ridge with the three kidneys in sequence and their ducts labelled — it is faster than a paragraph and the examiner can see the succession at a glance. Second, keep the duct hand-over explicit: pronephric duct becomes the Wolffian duct, which then sprouts the ureteric bud. Candidates who describe three kidneys without that thread have described three organs, not a succession. The version above is written for revision; in the hall the comparison table plus a labelled figure plus one paragraph per kidney is the whole answer.
Question 5(a) Any 4 of Q2 to Q7 Control of development 5 marks sketch expected Developmental biology half of the course
5. (a) What is embryonic induction? Explain the phenomenon with the help of a suitable example. 5
Meaning. Embryonic induction is the process in which one group of embryonic cells, the inducer, changes the developmental fate of a neighbouring group, the responder. The responding tissue must be competent, which means able to react to the signal at that stage. Without the inducer, the responder would form a different tissue.
Example: the Spemann organiser. In 1924 Hans Spemann and Hilde Mangold grafted the dorsal lip of the blastopore from an early gastrula of one newt species into the belly side of a gastrula of another species with differently pigmented cells. The host developed a second body axis, with a neural tube, notochord and somites, giving a conjoined secondary embryo.
The pigment difference showed that most of the second embryo came from host cells, not from the graft. The dorsal lip had therefore induced host tissue to form organs it would not normally make, and it was named the primary organiser. Spemann received the Nobel Prize in 1935 for this work.
Other examples and the molecular basis. Induction also works in chains: the optic vesicle induces the overlying ectoderm to form the lens, and the lens then induces the cornea. Modern work shows the organiser releases proteins such as chordin, noggin and follistatin, which block BMP-4 signalling in the dorsal ectoderm so that it becomes neural tissue instead of epidermis.
At five marks this answer needs one definition, one named experiment with its date, and a sketch — not four paragraphs. The labelled sketch of the dorsal-lip graft and the twin embryo does most of the work, and the pigment detail is what proves induction rather than mere transplantation, so keep that sentence. The molecular block (chordin, noggin, follistatin blocking BMP-4) is worth one line as a sign of current reading; drop the induction chain before you drop it.
Questions answered only in the full file
The remaining 23 items are printed below exactly as they appear in the June 2026 paper. Their answers are in the full solved file only.
1. (a) Fill in the blanks: 4 × ½ = 2
(i) Removal of adrenal glands results in loss of sodium in freshwater and gain of ........... in sea water.
(ii) The voice box of birds is called ............
(iii) Organization of differentiated cells into tissues and organs is called .............
(iv) The attainment of sexual maturity in larval condition is known as ..........1. (b) Differentiate between: 4 × 1 = 4
(i) Procoelous vertebra and Amphicoelous vertebra
(ii) Free sensory receptors and Encapsulated sensory receptors
(iii) Autonomous specification and Conditional specification
(iv) Hermaphroditism and Parthenogenesis1. (c) State whether 'True' or 'False': 4 × 1 = 4
(i) Amphioxus has isolecithal eggs.
(ii) During post gastrulation development, different germ layers of the gastrula become segregated from each other to form tissues and organs.
(iii) Reptiles and birds have a double membrane made up of outer dura mater and inner arachnoid layer to protect the brain.
(iv) The protein found in cartilage is collagen.2. (a) With the help of a neat labelled diagram explain the structure of mammalian skin. 5
(b) Discuss the pulmonary respiration in frog. 54. (a) Discuss the importance of pituitary gland in birds. 5
(b) Briefly explain the aortic arches in fishes. 55. (b) Describe the process of oogenesis in mammals. 5
6. (a) Discuss the process of gastrulation in animals. 5
(b) With the help of neat labelled diagrams explain the development of extraembryonic membranes in chick. 57. Write short notes on any two of the following: 2 × 5 = 10
(a) Fate map of Amphibian blastula
(b) Fertilization in humans
(c) Echolocation in bats
(d) Early tetrapod heart
BZYCT-133 syllabus areas tested in the June 2026 paper
The June 2026 paper tested nine syllabus areas, from the vertebrate integument and kidneys to gastrulation, chick membranes and the control of development. The table maps each area to the exact topics this paper asked about. IGNOU block and unit numbers for BZYCT-133 could not be confirmed from an official source while writing, so they are marked for checking rather than guessed. Read the matching chapters in your BZYCT-133 study material before attempting the full solved file.
| Syllabus area | Topics tested in June 2026 | Questions | Half of the course |
|---|---|---|---|
| Integument and skeleton | Layers of mammalian skin; procoelous and amphicoelous centra; collagen in cartilage | 1(b)(i), 1(c)(iv), 2(a) | Comparative anatomy |
| Respiration | Pulmonary breathing in the frog; the syrinx as the voice box of birds | 1(a)(ii), 2(b) | Comparative anatomy |
| Circulation | Aortic arches of fishes; the early tetrapod heart | 4(b), 7(d) | Comparative anatomy |
| Excretion | Pronephros, mesonephros and metanephros in sequence | 3 | Comparative anatomy |
| Nervous system and sense organs | Meninges of reptiles and birds; free and encapsulated receptors; echolocation in bats | 1(b)(ii), 1(c)(iii), 7(c) | Comparative anatomy |
| Endocrine glands | Adrenal removal and sodium balance in fishes; role of the pituitary in birds | 1(a)(i), 4(a) | Comparative anatomy |
| Gametes and fertilisation | Oogenesis in mammals; fertilisation in humans; hermaphroditism and parthenogenesis | 1(b)(iv), 5(b), 7(b) | Developmental biology |
| Early development | Isolecithal egg of amphioxus; gastrulation; fate map of the amphibian blastula | 1(c)(i), 6(a), 7(a) | Developmental biology |
| Late and controlled development | Organogenesis; chick extraembryonic membranes; induction; autonomous and conditional specification; neoteny | 1(a)(iii), 1(a)(iv), 1(b)(iii), 1(c)(ii), 5(a), 6(b) | Developmental biology |
BZYCT-133 question paper pattern and marks split
The June 2026 paper was worth 50 marks in 2 hours: a compulsory 10-mark Question 1, then any four of Questions 2 to 7 at 10 marks each.
| Question | Format | Choice | Marks |
|---|---|---|---|
| 1(a) | 4 fill-in-the-blanks (adrenal and sodium, syrinx, organogenesis, neoteny) | Compulsory | 4 × ½ = 2 |
| 1(b) | 4 pairs to differentiate (vertebrae, receptors, specification, reproduction) | Compulsory | 4 × 1 = 4 |
| 1(c) | 4 true-or-false statements (amphioxus egg, germ layers, meninges, cartilage) | Compulsory | 4 × 1 = 4 |
| 2, 4, 5, 6 | Long questions in two parts of 5 marks each | Attempt any four of Q2 to Q7 | 10 each |
| 3 | A single undivided 10-mark question | 10 | |
| 7 | Short notes — any two of four | 2 × 5 = 10 | |
| Total | Q1 plus four questions from Q2 to Q7 | 50 |
Q1 (10) + six questions of 10 in Q2 to Q7 = 70 marks printed, 50 attempted · four distinct mark values on one paper: 0.5, 1, 5 and 10 · 120 minutes for 50 marks = 2.4 minutes a mark · Q1 holds 12 of the paper's 25 items for 10 marks, which is 0.83 marks an item
Question 1 is the part of this paper where time does not convert into marks, and that should shape your plan. Its twelve items are pure recall — one word, one contrast, one true-or-false. If you know that the voice box of a bird is the syrinx, the item takes fifteen seconds; if you do not, no amount of staring will produce it. A proportional time plan would give Q1 a fifth of the paper, about 24 minutes, which is wasted on it.
Spend twelve to fifteen minutes on Question 1, bank what you know, and move on. That leaves about 105 minutes for four long questions, or roughly 26 minutes each — and those are the questions where an extra five minutes of recall and a better diagram genuinely add marks.
On answer length, we have corrected what this page previously said. It claimed about 300 words for a five-mark part and 600 for the ten-mark question, which works out to 60 words a mark. Five answers plus Q1 at that rate is roughly 2,700 words in 120 minutes, or 22 words a minute sustained — about double what anyone writes by hand, before you have drawn a single diagram. The realistic figures, allowing time for the three questions that need labelled figures, are:
| Part | Marks | Roughly how many words | Roughly how many minutes | What else it needs |
|---|---|---|---|---|
| Fill-in-the-blank | ½ | One word | Under a minute | Nothing |
| Differentiate between | 1 | Two contrasting points | 1 to 2 | A two-column layout reads faster than prose |
| True or false | 1 | The verdict alone | Under a minute | No reason is asked for; do not add one |
| A five-mark part | 5 | 125 to 150 | 13 | A labelled sketch where the question names structures |
| The ten-mark question | 10 | 250 to 300 | 26 | A labelled figure plus, here, a comparison table |
That comes to about 25 words a mark, in line with the 20 to 30 a mark IGNOU prints on its own arts papers — and it leaves room for the figures, which on a zoology paper earn marks directly and faster than prose does. A well-labelled diagram is worth more than the hundred extra words you would have spent describing it.
Students of other zoology courses can compare formats on our BSCG question paper page.
How the paper splits between the two halves of the course
BZYCT-133 is two subjects in one course, and the June 2026 paper did not offer them equally. Sorting every item by half makes that visible, and it leads to the most useful planning finding on this page.
| Part of the paper | Comparative anatomy | Developmental biology |
|---|---|---|
| Q1, compulsory (12 items, 10 marks) | 6 items — 1(a)(i), 1(a)(ii), 1(b)(i), 1(b)(ii), 1(c)(iii), 1(c)(iv) | 6 items — 1(a)(iii), 1(a)(iv), 1(b)(iii), 1(b)(iv), 1(c)(i), 1(c)(ii) |
| Choice questions, Q2 to Q6 | 3 questions — Q2 skin and frog respiration, Q3 kidneys, Q4 pituitary and aortic arches | 2 questions — Q5 induction and oogenesis, Q6 gastrulation and chick membranes |
| Q7 short notes (any two of four) | 2 options — 7(c) echolocation, 7(d) early tetrapod heart | 2 options — 7(a) fate map, 7(b) human fertilisation |
Question 1 is perfectly even, six items each. Whoever set the paper sampled both halves deliberately in the compulsory part, so there is no way to avoid either half entirely — you will lose marks in Q1 for whichever half you skipped.
The choice questions are not even, and the consequence is sharp. You must answer four of Questions 2 to 7. Work it through:
- Comparative anatomy alone is enough. Q2, Q3 and Q4 are all anatomy, and Question 7 can be taken as a fourth by writing the two anatomy notes, 7(c) and 7(d). That is four questions without opening a developmental biology chapter.
- Developmental biology alone is not enough. Q5 and Q6 are the only developmental questions, and Question 7 gives a third through 7(a) and 7(b). That is three. You would be one question short and forced into anatomy.
So on this paper the two halves were worth different amounts of insurance. If you are revising under time pressure for a future session, that asymmetry is worth knowing — but do not over-read it either. It reflects how one paper happened to fall, and a session that printed three developmental questions instead of two would reverse it. The safe reading is that Question 7 is the swing question: because its four options split two and two, it can be made to serve whichever half you have prepared, and it is the only question on the paper that can.
BZYCT-133 June 2026 topics by marks weight
Kidney succession was the only topic set as a full 10-mark question; every other long topic carried 5 marks. The table ranks the June 2026 topics by the marks they carried.
| Topic | Question | Marks | Half of the course | Diagram needed? |
|---|---|---|---|---|
| Succession of kidneys in vertebrates | 3 | 10 | Comparative anatomy | Expected |
| Structure of mammalian skin | 2(a) | 5 | Comparative anatomy | Asked for |
| Pulmonary respiration in frog | 2(b) | 5 | Comparative anatomy | Helpful |
| Pituitary gland in birds | 4(a) | 5 | Comparative anatomy | Helpful |
| Aortic arches in fishes | 4(b) | 5 | Comparative anatomy | Expected |
| Embryonic induction with example | 5(a) | 5 | Developmental biology | Expected |
| Oogenesis in mammals | 5(b) | 5 | Developmental biology | Expected |
| Gastrulation in animals | 6(a) | 5 | Developmental biology | Expected |
| Extraembryonic membranes in chick | 6(b) | 5 | Developmental biology | Asked for |
| Fate map of amphibian blastula | 7(a) | 5 (option) | Developmental biology | Expected |
| Fertilization in humans | 7(b) | 5 (option) | Developmental biology | Helpful |
| Echolocation in bats | 7(c) | 5 (option) | Comparative anatomy | Helpful |
| Early tetrapod heart | 7(d) | 5 (option) | Comparative anatomy | Expected |
Read the last column before you choose your four questions. Two questions name a diagram in the question itself — mammalian skin and the chick membranes — and a further six are topics where a figure is the natural way to answer: the nephric ridge, the aortic arches, the dorsal-lip graft, the fate map, the tetrapod heart. If drawing is your strength, those are cheap marks; if it is not, Q2(b) on frog respiration, Q4(a) on the avian pituitary and Q7(b) on human fertilisation are the most answerable in prose alone.
One honest gap on this page. We have not shown a repeat count across earlier sessions, because we have not yet matched every earlier official BZYCT-133 paper. That means this page can tell you what June 2026 asked and how it was weighted, but it cannot yet tell you which topics IGNOU returns to or which ones June 2026 skipped — the analysis we publish for courses where we hold the full run of papers. We would rather say so than print a count we cannot stand behind. For a wider topic list meanwhile, see our IGNOU Solved Guess Paper page.
How our BZYCT-133 answers are written and checked
Every answer is drafted by our zoology team from the IGNOU course material, then checked for facts, length and labelled diagrams before it goes into the file. The file is prepared by the team led by Prateek Talwar, Academic Head of Unnati Educations, and reviewed by Sheetal Kirola.
We start from the official June 2026 paper exactly as printed, then answer each part at the depth its marks deserve. A one-mark difference, such as procoelous against amphicoelous centra, gets two clear contrasting points and nothing more; a five-mark part, such as oogenesis, gets the stages, a sketch and a closing line.
The review checks the names and dates that examiners notice — the 1924 Spemann and Mangold experiment, Spemann's 1935 Nobel Prize, the BMP-4 antagonists — and confirms that each diagram shows the structures the question names. You can match our question text against the official IGNOU June 2026 BZYCT-133 question paper.
BZYCT-133 solved file index: all 25 answerable items
The full file answers all 25 items of the June 2026 paper; 2 are on this page and 23 are in the full file only. BZYCT-133 is a theory course, so this index lists the solved answers rather than practical records — the practical side is covered by the companion lab course, BZYCL-134.
| Question | Syllabus area | Marks | Where to find the answer |
|---|---|---|---|
| Q1(a)(i) | Endocrine system — osmoregulation in fishes | ½ | Full file only |
| Q1(a)(ii) | Respiratory system of birds | ½ | Full file only |
| Q1(a)(iii) | Post-gastrulation development | ½ | Full file only |
| Q1(a)(iv) | Post-embryonic development | ½ | Full file only |
| Q1(b)(i) | Skeletal system — vertebral centra | 1 | Full file only |
| Q1(b)(ii) | Sense organs — receptors | 1 | Full file only |
| Q1(b)(iii) | Cell fate specification | 1 | Full file only |
| Q1(b)(iv) | Reproductive strategies | 1 | Full file only |
| Q1(c)(i) | Egg types and cleavage | 1 | Full file only |
| Q1(c)(ii) | Post-gastrulation development | 1 | Full file only |
| Q1(c)(iii) | Nervous system — meninges | 1 | Full file only |
| Q1(c)(iv) | Skeletal system — cartilage | 1 | Full file only |
| Q2(a) | Integumentary system | 5 | Full file only |
| Q2(b) | Respiratory system — amphibians | 5 | Full file only |
| Q3 | Excretory system | 10 | On this page |
| Q4(a) | Endocrine system — birds | 5 | Full file only |
| Q4(b) | Circulatory system — fishes | 5 | Full file only |
| Q5(a) | Control of development | 5 | On this page |
| Q5(b) | Gametogenesis | 5 | Full file only |
| Q6(a) | Early embryonic development | 5 | Full file only |
| Q6(b) | Late embryonic development — chick | 5 | Full file only |
| Q7(a) | Early embryonic development — amphibians | 5 | Full file only |
| Q7(b) | Fertilisation | 5 | Full file only |
| Q7(c) | Sense organs — mammals | 5 | Full file only |
| Q7(d) | Circulatory system — tetrapods | 5 | Full file only |
Use this index to check that the topic you are weakest in — the chick membranes or the avian pituitary, say — is covered before you order.
Which IGNOU programmes include BZYCT-133
The June 2026 paper header lists two programmes: BSCG and BSCM. Students of the IGNOU Bachelor of Science (General) who chose zoology study BZYCT-133 as a core zoology course, and the same paper is printed for the Bachelor of Science (Multidisciplinary), so one solved file serves both groups.
BZYCT-133 is a 4-credit theory course taken together with its 2-credit companion lab, BZYCL-134, so zoology students complete 6 credits for the pairing. The lab covers the practical side of the same topics; this solved file covers the theory paper only.
One point worth noting if you are comparing courses across IGNOU: BZYCT-133 carries 4 credits and a 50-mark, two-hour paper, while BTME-141 carries 4 credits and a 100-mark, three-hour paper, BSOC-101 carries 6 credits and a 100-mark paper, and BPCC-107 carries 6 credits and a 50-mark paper. All four combinations exist, so the credit count tells you nothing about the exam format. Always check the paper itself.
How to get the full BZYCT-133 Solved Question Paper on WhatsApp
Message us on WhatsApp at 9899436384 with the code BZYCT 133 and the session June 2026 to receive the solved paper with all 25 answers.
Ordering takes three steps. Send the code and session on WhatsApp; complete the payment using the details we reply with; receive the solved file with answers to the 23 items not shown here, plus the two you have already read.
Mention any doubt in the same chat — for example whether you are a BSCG or BSCM student — and we will confirm that this paper matches your course code.
BZYCT-133 FAQs
How do I get the full BZYCT-133 Solved Question Paper June 2026 on WhatsApp?
Send a WhatsApp message to 9899436384 with the course code BZYCT 133 and the session June 2026. Our team replies with the payment details and then shares the solved file. It contains answers to all 25 answerable items of the paper: the 12 short parts of Question 1, every long question from 2 to 6, and all four short-note options of Question 7.
How many questions are in the BZYCT-133 June 2026 question paper?
Seven numbered questions that break into 25 answerable items. Question 1 alone has 12 parts — four fill-in-the-blanks worth half a mark each, four differences worth one mark each and four true-or-false statements worth one mark each. Questions 2 to 6 carry ten marks each, mostly split into two parts of five, and Question 7 offers four short notes of which you attempt any two. You answer Question 1 plus any four of Questions 2 to 7.
Which BZYCT-133 answers can I read on this page?
Two complete answers: Question 3 on the succession of kidneys in vertebrates and Question 5(a) on embryonic induction. We chose one comparative anatomy answer and one developmental biology answer so you can judge both halves of the course. The other 23 answers, including the chick membranes and mammalian skin questions, are only in the full file.
How should I divide time in the BZYCT-133 two-hour exam?
Two hours for 50 marks is 2.4 minutes a mark, but do not spend it proportionally. Question 1's twelve items are pure recall — you either know that a bird's voice box is the syrinx or you do not, and extra time will not help. Give Question 1 twelve to fifteen minutes, bank what you know, and move on. That leaves about 105 minutes for your four long questions, or 26 minutes each, which is where extra time actually earns marks. Keep the last few minutes for labelling diagrams.
How long should each BZYCT-133 answer be?
Shorter than you might think, because the diagrams take time. A realistic plan is about 125 to 150 words for a five-mark part and 250 to 300 for the ten-mark question — roughly 25 words a mark — plus the labelled figure. A true-or-false item needs the verdict alone, with no reason, and a "differentiate between" item needs two contrasting points, best set out in two columns. On a zoology paper a well-labelled diagram earns marks faster than a hundred extra words of description.
Does the BZYCT-133 solved paper explain the diagrams the paper asks for?
Yes. Two questions name a diagram explicitly — mammalian skin in Question 2(a) and the extraembryonic membranes of the chick in Question 6(b) — and several more are topics where a figure is the natural answer, such as the aortic arches and the nephric ridge. The solved file tells you which structures to label in each figure, for example the amnion, chorion, allantois and yolk sac, so your diagram earns marks rather than just filling space.
Which BZYCT-133 topics carry the most marks in June 2026?
The succession of kidneys is the only topic set as a full ten-mark question. Every other long question is split into five-mark parts covering skin, frog respiration, the avian pituitary, aortic arches, induction, oogenesis, gastrulation and chick membranes. Comparative anatomy fills Questions 2, 3 and 4 while developmental biology fills Questions 5 and 6, and Question 7's four notes split evenly between the two halves.
Can I answer the BZYCT-133 paper from only one half of the course?
From comparative anatomy, yes; from developmental biology, no. You need four of Questions 2 to 7. Comparative anatomy gives you Q2, Q3 and Q4, and Question 7 can be your fourth by writing the two anatomy notes. Developmental biology gives you only Q5, Q6 and Question 7 — three questions, one short. Either way, Question 1 is compulsory and splits its twelve items evenly between the two halves, so neither strategy avoids it. Note too that this reflects how one paper fell; a session with three developmental questions would reverse it.
Is BZYCT-133 part of BSCM as well as BSCG?
Yes. The June 2026 question paper header lists both BSCG and BSCM, so the course is examined for the Bachelor of Science (General) and the Bachelor of Science (Multidisciplinary). The same paper and the same solved file work for students of both programmes who chose zoology as a discipline.
Can the BZYCT-133 June 2026 solved paper help for the December 2026 exam?
Yes, as practice. IGNOU sets BZYCT-133 questions on the same core areas session after session — kidney succession, aortic arches, gastrulation, extraembryonic membranes — so writing complete answers from June 2026 builds the answer length and the diagram habit you need. We have not yet published a repeat count for this course, so treat the file as practice alongside your study material rather than as a prediction of the December questions.
About the authors
This page was prepared by the academic team at Unnati Educations, which has been helping IGNOU, NIOS, MDU Rohtak and GGSIPU students with solved papers and assignment support for over a decade.
Prateek Talwar, Academic Head, led the writing of the BZYCT-133 answers and built the syllabus mapping and the analysis on this page, including the item-by-item split between the two halves of the course and the corrected answer-length table. He reads every official paper in a series before a single answer is drafted.
Sheetal Kirola reviewed this page and the solved file against the printed question wording and marks, and verified the zoological detail used — the development of all three kidneys from intermediate mesoderm, the archinephros plan in hagfish and caecilian larvae, the hand-over of the pronephric duct to the mesonephros as the Wolffian duct and the ureteric bud's origin from it, the opisthonephros of adult fishes and amphibians, the loop of Henle in mammals and in part of avian nephrons, and for Question 5(a) the 1924 Spemann and Mangold dorsal-lip graft, Spemann's 1935 Nobel Prize, the optic vesicle and lens induction chain, and chordin, noggin and follistatin as BMP-4 antagonists.