BGYCT 135 Question Paper December 2025 is the most recent paper you can practise before sitting your 2026 Term-End Exam. The solved version walks you through every textural sketch, every classification, and every long answer the way an IGNOU evaluator wants to read it on the actual answer sheet.
About This Solved Paper
| Prepared by | Unnati Education academic team, IGNOU-experienced content writers |
|---|---|
| Qualification | M.Sc. Geology graduate with classroom teaching background in petrology and field geology |
| Programme | IGNOU Bachelor of Science (General) (BSCG) |
| Institution Reference | IGNOU Term-End Examination, December 2025 |
The download is one neat PDF, available within seconds of payment. Your link arrives by email and inside your Unnati Education dashboard at the same time. Read it on a phone, tablet, or laptop. If you like writing answers next to printed material, it prints on A4 with diagrams kept legible. No Telegram links to chase, no waiting room, no bandwidth hassle.
What is the BGYCT-135 December 2025 Question Paper?
The BGYCT 135 December 2025 question paper is the official IGNOU Term-End Examination paper for Petrology, conducted in December 2025 for BSCG students. It carries 50 marks across four compulsory questions, runs for two hours, and follows IGNOU's standard descriptive format.
Why it matters for you: this is the freshest paper IGNOU has released for the course. Question patterns from the latest cycle nearly always echo into the next two sessions. Solving December 2025 thoroughly is the closest you'll get to a live preview of June 2026 or December 2026.
About IGNOU BGYCT-135 Petrology
BGYCT-135 is a 4-credit core course in the IGNOU B.Sc. (General) programme, focused entirely on rocks: how they form, how they're classified, and how they're identified. The syllabus runs across four blocks. Block 1 introduces igneous rocks, magma types, modes of occurrence, textures, and classification including the IUGS scheme. Block 2 covers sedimentary rocks, weathering, lithification, and primary structures.
Block 3 deals with metamorphism, types and grades, metamorphic minerals, and the structures and textures of metamorphic rocks. Block 4 closes with rock associations and Indian examples. Most students underestimate how visual this course is. The questions look descriptive, but the marks sit in well-drawn diagrams. That's worth remembering when you plan your preparation.
BGYCT 135 Question Paper December 2025, Exam Pattern and Marks Breakdown
| Aspect | Detail |
|---|---|
| Duration | 2 Hours |
| Total Marks | 50 |
| Number of Questions | 4 main questions with sub-parts |
| Questions to Attempt | All 4 are compulsory, internal choice in Q3 and Q4 |
| Marks per Question | Q1 carries 10 (5×2), Q2 carries 20 (4×5), Q3 carries 10, Q4 carries 5+5 |
| Calculator Policy | Not required, fully descriptive paper |
| Missing Data Assumption | State your assumption clearly and continue |
| Diagram Requirement | Mandatory wherever asked, well labelled |
Q2 holds the biggest single mark block, 20 out of 50. Build your time around it. Most students who score above 70 percent in BGYCT-135 spend roughly 45 minutes of their 120 minutes on Q2 alone.
All Questions in the BGYCT 135 Question Paper December 2025 (Complete List)
BGYCT-135: PETROLOGY
Time: 2 Hours Maximum Marks: 50
Note: All questions are compulsory. Marks allotted for each question are indicated against it. Draw well-labelled diagrams wherever necessary.
1. Briefly answer any five of the following questions: 5×2=10
- (a) List the type of igneous rocks based on mode of occurrence.
- (b) Differentiate between lithification and diagenesis.
- (c) Define graphic texture.
- (d) Define protolith.
- (e) What are essential minerals?
- (f) Mention the volcanic equivalent of granite and gabbro.
- (g) What is quartz arenite?
- (h) What is reaction rim texture?
2. Write short notes on any four of the following: 4×5=20
- (a) Types of sedimentary rocks
- (b) Chemical weathering
- (c) Components of classic texture
- (d) Metamorphic minerals
- (e) High-temperature limit of metamorphism
- (f) IUGS classification
3. Answer any one of the following: 10
- (a) Describe briefly the textures found in igneous rocks and give suitable examples. Or
- (b) Explain the structures found in metamorphic rocks with the help of neat well-labelled diagrams.
4. Answer any one of the following:
- (a) (i) Discuss the factors affecting the textures in metamorphic rocks. 5 (ii) What are ultramafic rocks? Discuss the megascopic characters of peridotite. 5
- Or
- (b) (i) Describe the five commonly found forms of igneous rock with the help of neat well-labelled diagrams. 5 (ii) Discuss any five types of commonly occurring primary structures in sedimentary rocks. 5
Topics tested in this paper: igneous rock types, lithification vs diagenesis, mineral properties, sedimentary rocks, metamorphism, rock textures, ultramafic rocks, geological structures.
Syllabus Topics Covered
The solutions in this PDF map directly onto the four blocks of BGYCT-135. Q1 short answers pull from across the syllabus, mostly definitions and quick distinctions. Q2 short notes lean heavily on Block 2 (sedimentary, weathering) and Block 3 (metamorphism), with one option from Block 1 igneous classification.
Q3 always tests either igneous textures or metamorphic structures in depth, and December 2025 offered both as a choice. Q4 splits five marks each across two diagram-heavy parts. If you've prepared igneous textures with examples, sedimentary primary structures, metamorphic structures, IUGS classification, and ultramafic rocks like peridotite, you've covered nearly every recurring pattern in the last six sessions.
Sample Answer Preview: BGYCT-135 Petrology Explanation
Take Q3(b), the 10-mark question on structures in metamorphic rocks. This is the kind of question where the diagram is the answer, and the prose just supports it.
Here's how those 10 marks actually break down in practice:
Definition (1 mark): Open with one tight line. Metamorphic structures are large-scale features produced by directed pressure, temperature, and recrystallisation acting on a parent rock. Don't ramble.
Classification (1 mark): Mention that metamorphic structures are broadly grouped as foliated and non-foliated. One line is enough.
Foliated structures with diagram (4 marks): Cover slaty cleavage, schistosity, gneissic banding, and phyllitic structure. Each gets a small labelled sketch showing how mineral grains align under stress. Slaty cleavage shows fine parallel planes. Schistosity shows visible mica flakes lined up. Gneissic banding shows alternating light and dark bands. The labels carry weight, not the prose.
Non-foliated structures with diagram (3 marks): Cover granulose (granoblastic) and hornfelsic structures. One sketch each, with grain shapes and arrangement labelled.
Examples and field context (1 mark): Tie each structure to a real rock. Slate for slaty cleavage, schist for schistosity, gneiss for banding, marble or quartzite for granulose. Examiners reward students who connect structure to rock name.
The full solution in your PDF follows exactly this shape, with all five sketches drawn out and ready for you to copy onto your answer sheet.
How to Write High-Scoring Answers
Time first. 50 marks in 120 minutes is roughly 2.4 minutes per mark. Q2 alone deserves about 45 minutes of focused writing. If you spend more than 25 minutes on Q1, you'll regret it during Q4.
Open every long answer with a one-line definition, even when not asked. IGNOU evaluators almost always award the first mark for a clean opening line.
For petrology, your sketch is your highest-scoring asset. Draw it in pencil, ink the labels, point to grain orientation with arrows. A neat labelled sketch of slaty cleavage often scores higher than a paragraph trying to describe it.
For Q1, four lines are plenty. Don't write a paragraph for two marks. Many students lose Q4 time because they over-explained Q1.
For short notes in Q2, follow a fixed shape: definition, two or three features, one example, one sketch if it adds value. Examiners scan for structure, not paragraph length.
Who Should Use This Solved Question Paper
This is built for the BSCG student whose Term-End Exam falls in 2026 or beyond. June 2026 candidate, December 2026 candidate, back-paper attempt, the December 2025 release is your closest, cleanest practice resource.
Two student profiles benefit most. The working professional who picked up an IGNOU degree alongside a job and gets 30 to 60 minutes a day for revision. And the first-time distance learner who hasn't yet figured out what "well-labelled diagram" actually means in IGNOU terms.
Self-study students who don't attend regional study centre counselling will find the diagram approach especially useful as a model.
Why This is Better Than Free PDFs and Telegram Files
Free PDFs look tempting until you actually open one. Most are old papers, badly scanned, with answers stitched from random blogs. Diagrams are missing, mislabelled, or drawn so small you can't read them. Half the time the file doesn't even tell you which session the paper belongs to.
The real cost isn't money. It's writing a wrong answer in your final exam because you trusted a careless file. We've seen students label slaty cleavage as schistosity in their actual paper because a free PDF had the diagrams swapped.
This solved paper is checked against the official IGNOU release, written by a subject expert who teaches petrology, and corrected when something needs an update. There's also a real human at the other end if you spot anything off.
Student Reviews
Aakash, Ranchi. Working as a junior geologist at a state mining department, doing IGNOU to formalise the degree. The metamorphic structures question in Q3(b) was the clearest explanation I've seen anywhere. I sketched all five structures from memory after one read.
Divya, Indore. First-year BSCG student, full-time student at home preparing for civils too. Honestly, igneous textures used to confuse me because every textbook used different names. The texture comparison in this paper sorted it out in one sitting.
Faiz, Kochi. Second-year student, part-time tuition teacher. The peridotite megascopic description in Q4(a) was exactly what my study centre tutor had hinted at. I used the same structure in my mock and the evaluator gave full marks. Worth every rupee.
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Frequently Asked Questions
Is this the actual BGYCT-135 December 2025 IGNOU paper?
Yes, this is the genuine IGNOU Term-End Examination paper from December 2025, reproduced exactly as it appeared in the exam hall. We've matched every question word for word against the official IGNOU release for BSCG students. The solutions are written by our subject expert team, but the questions themselves are completely authentic and verifiable against the institute's records.
Will this paper help me for the June 2026 or December 2026 exam?
Absolutely, the December 2025 paper is the sharpest practice resource for any 2026 attempt. IGNOU recycles topic patterns, expected sub-parts, and definition formats across cycles, so the patterns you spot here repeat. Most students who solve this paper twice and study the answer structures report a noticeable jump in their petrology marks during the actual exam they sit.
Are the diagram-based and theory questions fully solved?
Yes, every diagram-based question is fully drawn and labelled the way IGNOU evaluators expect. Igneous textures, metamorphic structures, sedimentary primary structures, all sketched out. BGYCT-135 is a descriptive course rather than numerical, so the focus stays on accurate diagrams and structured prose. Each long answer comes with a marks-wise breakdown so you can see where the scoring actually happens.
Can I use this for my BGYCT-135 assignment too?
You can use it as a reference, but please don't copy it straight into your assignment. IGNOU runs plagiarism checks and direct copying risks rejection or zero marks. Treat this solved paper as a structure guide, study how points are arranged, then write your assignment in your own words. Most students use it to internalise the answer pattern first, then frame original responses for assignment submission.
How quickly will the file reach me after payment?
The PDF is delivered the moment your payment goes through. Your download link reaches your registered email and your Unnati Education account dashboard within a minute. There's no manual sending, no Telegram redirect, no waiting period. If the email lands in spam or you face any glitch, our support team responds on WhatsApp the same day to share the file with you directly.
What if there's an error or I'm not satisfied?
You're protected. Write to our support team within 48 hours and we will fix it or refund you. We take quality seriously because most of our team has actually sat in IGNOU exam halls. If a question is missing, a diagram unclear, or content does not match the official paper, we either send a corrected version or process the refund without putting you through any argument.
About Unnati Education
Unnati Education is a small academic team that builds study material specifically for IGNOU students. The people who write our papers have either studied at IGNOU themselves or taught at IGNOU study centres. We're not a mass-produced PDF mill. Every solved paper is reviewed by a subject expert before it goes live, and we update files when IGNOU changes weightage or releases a new session.
Explore More IGNOU BGYCT-135 Study Material
If this paper helps, you might also want the previous session solved papers (June 2025, December 2024), the BGYCT-135 assignment solutions for the current session, an important questions guide for last-minute revision, and topic-wise notes for Block 3 metamorphism, which most students find the most diagram-heavy section. Bundle pricing kicks in if you pick up two or more resources together.