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Biomolecules WBCHSE Class 12 MCQ & Practice Questions

Practice Biomolecules MCQs for WBCHSE Class 12 Chemistry with answers, explanations, chapter revision and related ChemNexa mock tests.

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Biomolecules Revision Guide for WBCHSE Class 12 Chemistry

Biomolecules is part of WBCHSE Class 12 Chemistry preparation. A strong revision plan should combine concept review with exam-style questions so that definitions, relationships, calculations and exceptions are recalled accurately.

Use the sample MCQs on this page to check understanding, then attempt the related ChemNexa tests for broader practice. When an answer is wrong, review the explanation and return to the underlying concept before attempting another set.

Important Topics

  • Core definitions and principles
  • Important equations or relationships
  • Common applications and examples
  • Frequently confused concepts
  • Exam-style multiple-choice questions
  • Error review and targeted revision

Revision Tip

Create a one-page summary of trends, structures, reactions, exceptions and key terminology for Biomolecules, then test recall with mixed MCQs.

What to practise in Biomolecules

Concept Revision

Revise definitions, principles, equations, trends and core ideas from Biomolecules before attempting MCQs.

Exam-style MCQs

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Top 20 Biomolecules MCQs with Answers

These public questions are selected from the exact Biomolecules chapter, screened for topic relevance and deduplicated so repeated versions of the same MCQ are not shown publicly. Use them for quick revision, then sign in to attempt the complete test experience with more questions, results and performance review.

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

1. Glucose কোন শ্রেণির monosaccharide?

  • A. Aldopentose
  • B. Aldohexose
  • C. Ketohexose
  • D. Ketopentose
Answer: B
Explanation: Glucose ছয় carbon বিশিষ্ট aldose; তাই aldohexose।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

2. Fructose কোন শ্রেণির monosaccharide?

  • A. Aldohexose
  • B. Ketohexose
  • C. Aldopentose
  • D. Ketotriose
Answer: B
Explanation: Fructose ছয় carbon বিশিষ্ট ketose; ketohexose।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

3. Sucrose hydrolysis-এ কী দেয়?

  • A. Glucose + glucose
  • B. Glucose + fructose
  • C. Fructose + fructose
  • D. Glucose + galactose
Answer: B
Explanation: Sucrose hydrolysis-এ এক mol glucose ও এক mol fructose তৈরি হয়।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

4. Sucrose reducing sugar নয় কেন?

  • A. কোন O নেই
  • B. উভয় anomeric carbon glycosidic bond-এ যুক্ত
  • C. এটি polymer
  • D. এতে fructose নেই
Answer: B
Explanation: Sucrose-এ glucose ও fructose-এর anomeric centres bond-এ যুক্ত থাকায় free hemiacetal/hemiketal নেই।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

5. Starch-এর প্রধান monomer কী?

  • A. β-D-glucose
  • B. α-D-glucose
  • C. Fructose
  • D. Galactose
Answer: B
Explanation: Starch α-D-glucose units-এর polymer।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

6. Cellulose-এর monomer কী?

  • A. α-D-glucose
  • B. β-D-glucose
  • C. Fructose
  • D. Ribose
Answer: B
Explanation: Cellulose β-D-glucose units-এর β(1→4) polymer।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

7. মানবদেহ cellulose হজম করতে পারে না কেন?

  • A. amylase নেই
  • B. cellulase enzyme নেই
  • C. glucose toxic
  • D. cellulose lipid
Answer: B
Explanation: মানুষের digestive system-এ β(1→4) bond ভাঙার cellulase নেই।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

8. Peptide bond কোন functional linkage?

  • A. –CO–O–
  • B. –CO–NH–
  • C. –NH–NH–
  • D. –O–O–
Answer: B
Explanation: এক amino acid-এর –COOH ও অন্যটির –NH2 condensation-এ –CO–NH– peptide bond তৈরি হয়।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

9. Protein-এর primary structure কী নির্দেশ করে?

  • A. শুধু helix
  • B. amino acid sequence
  • C. subunit সংখ্যা
  • D. শুধু molecular mass
Answer: B
Explanation: Primary structure হলো polypeptide chain-এ amino acid-এর নির্দিষ্ট sequence।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

10. Protein denaturation-এ সাধারণত কোন bond অক্ষুণ্ণ থাকে?

  • A. Peptide bond প্রধানত
  • B. সব covalent bond ভাঙে
  • C. C–C সব ভাঙে
  • D. DNA bond
Answer: A
Explanation: Denaturation secondary/tertiary interactions নষ্ট করে; সাধারণত peptide backbone hydrolyse হয় না।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

11. Enzyme কী?

  • A. অধিকাংশ ক্ষেত্রে biological catalyst
  • B. শুধু carbohydrate
  • C. DNA monomer
  • D. inorganic salt only
Answer: A
Explanation: Enzyme জীবদেহে reaction rate বাড়ায়; অধিকাংশ enzyme protein, কিছু RNA-ও catalytic।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

12. DNA-তে sugar কোনটি?

  • A. Ribose
  • B. 2-deoxyribose
  • C. Glucose
  • D. Fructose
Answer: B
Explanation: DNA nucleotide-এ pentose sugar হলো 2-deoxyribose।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

13. RNA-তে sugar কোনটি?

  • A. Ribose
  • B. Deoxyribose
  • C. Glucose
  • D. Galactose
Answer: A
Explanation: RNA nucleotide-এ ribose sugar থাকে।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

14. DNA-তে কোন base থাকে কিন্তু RNA-তে সাধারণত থাকে না?

  • A. Adenine
  • B. Guanine
  • C. Thymine
  • D. Cytosine
Answer: C
Explanation: DNA-তে thymine থাকে; RNA-তে তার পরিবর্তে uracil থাকে।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

15. RNA-তে কোন base DNA-র thymine-এর পরিবর্তে থাকে?

  • A. Uracil
  • B. Adenine
  • C. Guanine
  • D. Cytosine
Answer: A
Explanation: RNA-তে pyrimidine base uracil থাকে।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

16. Nucleoside কী দিয়ে গঠিত?

  • A. Sugar + phosphate
  • B. Base + sugar
  • C. Base + phosphate
  • D. Base only
Answer: B
Explanation: Nitrogenous base + pentose sugar = nucleoside।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

17. Nucleotide কী দিয়ে গঠিত?

  • A. Nucleoside + phosphate
  • B. Sugar only
  • C. Base only
  • D. Protein + sugar
Answer: A
Explanation: Nucleoside-এর সঙ্গে phosphate যুক্ত হলে nucleotide হয়।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

18. α-amino acid-এ –NH2 ও –COOH কোথায় থাকে?

  • A. একই α-carbon-এ
  • B. দুই terminal carbon-এ সবসময়
  • C. benzene ring-এ
  • D. phosphate carbon-এ
Answer: A
Explanation: α-amino acid-এ amino ও carboxyl group একই α-carbon-এর সঙ্গে যুক্ত।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

19. Zwitterion-এ কী থাকে?

  • A. শুধু positive charge
  • B. শুধু negative charge
  • C. একই molecule-এ + ও − charge
  • D. কোন charge নয়
Answer: C
Explanation: Amino acid নির্দিষ্ট pH-এ –NH3+ এবং –COO− সহ dipolar zwitterion হিসেবে থাকে।

WBCHSE Class 12 Chemistry · Biomolecules · Very Hard

20. Glycine optically inactive কেন?

  • A. N নেই
  • B. α-carbon-এ দুটি H থাকে
  • C. COOH নেই
  • D. এটি ketose
Answer: B
Explanation: Glycine-এর α-carbon দুইটি H-এর সঙ্গে যুক্ত; চারটি ভিন্ন group নেই, তাই achiral।

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Biomolecules Frequently Asked Questions

How should I prepare Biomolecules for WBCHSE Class 12 Chemistry?

Revise the core concepts first, make a short list of important relationships or exceptions, and then solve chapter-focused MCQs while reviewing every error.

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