TN 11th Biology Question Paper 2025 PDF: Check Difficulty Level, Exam Pattern

The Directorate of Government Examinations, Tamil Nadu (DGE TN) is conducting the public exams from March 5 to March 27, 2025, and the practical exams were held from February 15 to 21, 2025. The date of Tamil Nadu Class 11 Biology Exam 2025 is March 17, 2025, for the Higher Secondary (HSE +1) Public Exams. The examination is important to students as it forms the backbone of Class 12 board examinations and competitive entry tests such as NEET.

Latest: Tamil Nadu 11th Exam Time Table 2025: Download PDF

This Story also Contains

1. Tamil Nadu Class 11 Biology Paper: Highlights
2. Tamil Nadu Class 11 Biology Question Paper 2025: Download PDF
3. How to Use Tamil Nadu Class 11 Biology Question Paper and Answers?
4. Tamil Nadu Class 11 Biology Answer Key 2025: Check Solutions

Candidates who wrote the exam are now able to download the question paper PDF as well as the detailed solutions. Question paper will help future students to know the exam pattern, analyse the kinds of questions, the marking scheme, and thus it is a must-have for exam preparation.

Tamil Nadu Class 11 Biology Paper: Highlights

Given below are the important dates of Tamil Nadu Class 11 Biology Question Paper 2025 along with details:

Tamil Nadu Class 11 Biology Question Paper 2025: Download PDF

Candidates who wrote the Tamil Nadu Class 11 Biology Exam on March 17, 2025, may now get the Tamil Nadu 11th Biology question paper 2025 PDF download with solution for reference and practice. The TN HSE +1 biology question paper 2025 will help future students to know the pattern of the exam, nature of questions, and marking scheme.

Here are some important questions from TN Board Class 11 Biology Exam 2025, along with their answers:

Ques 1: Explain how photosynthesis occurs and describe the function of chlorophyll.

Ans: Photosynthesis is a process of converting light energy into chemical energy in green plants, using carbon dioxide and water. The process takes place in chloroplasts and has two phases:

Light Reaction: Takes place in the thylakoid membrane, where light energy is utilized to cleave water molecules, producing oxygen and forming ATP and NADPH.

Dark Reaction (Calvin Cycle): Occurs in the stroma, where ATP and NADPH assist in the CO₂ fixation into glucose.

Role of Chlorophyll:

• Chlorophyll absorbs light energy, primarily from the blue and red ends of the spectrum.
• It is responsible for initiating the light-dependent reactions of photosynthesis.

Ques 2: Name the enzymes involved in digestion of carbohydrates and mention their function.

Ans: Salivary Amylase (Ptyalin): Hydrolyzes starch to maltose in the mouth.

Pancreatic Amylase: Hydrolyzes starch to maltose in the small intestine.

Maltase, Sucrase, Lactase: Hydrolyzes disaccharides to monosaccharides for absorption.

Ques 3: What is anaerobic respiration? Explain its process with an example.

Ans: Anaerobic respiration is a form of cellular respiration that happens in the absence of oxygen. Rather than utilizing oxygen to degrade glucose, cells utilize other molecules as electron acceptors to derive energy. It occurs in the cytoplasm of cells and yields less ATP than aerobic respiration.

Process of Anaerobic Respiration:

• Glucose Breakdown: Glucose (C₆H₁₂O₆) is broken down partially into simpler molecules.
• ATP Yield: 2 ATP molecules are produced from each glucose molecule.
• End Products: Various byproducts are produced depending on the organism.

Example: In the muscles of human beings, during strenuous exercise, when oxygen is in short supply, glucose is converted to lactic acid and ATP. This leads to muscle fatigue.

In yeast, anaerobic respiration results in the production of ethanol and carbon dioxide, a process employed in fermentation.

How to Use Tamil Nadu Class 11 Biology Question Paper and Answers?

• Examine the question distribution in the TN board class 11 biology exam 2025 to find out the often-tested topics and their weightage.
• Practice answering lengthy answers with labelled diagrams to improve clarity and presentation.
• Compare with previous year's papers to identify repeated questions and main areas of focus.
• Analyze time management ability by attempting the Tamil Nadu 11th public Exam biology paper 2025 in timed conditions.
• Recognize difficult and application-based questions of TN HSE +1 Biology question paper 2025 to improve concept clarity.
• Study answer patterns from Tamil Nadu 11th answer key 2025 Biology, to understand how to write high-scoring answers properly.

Tamil Nadu Class 11 Biology Answer Key 2025: Check Solutions

Candidates who wrote the Tamil Nadu Class 11 Biology Exam 2025 on March 17, 2025, are now able to verify their performance using the answer key. The unofficial answer key offers detailed solutions to the Tamil Nadu 11th public exam biology paper 2025 sections and helps students to analyse their answers and estimate their marks.