Tamil Nadu 12th Std Model Question Paper 2026 Bio Chemistry

Tamil Nadu Board Model Question Paper

No. of Printed Pages : 8
8363
!8363BioChemistry! £vÄ Gs
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PART - III
E°º ÷Áv°¯À / BIO-CHEMISTRY
(uªÌ ©ØÖ® B[Q» ÁÈ / Tamil & English Version)

Põ» AÍÄ : 3.00 ©o ÷|µ® ] [ ö©õzu ©v¨ö£sPÒ : 70

Time Allowed : 3.00 Hours ] [ Maximum Marks : 70

AÔÄøµPÒ : (1) AøÚzx ÂÚõUPЮ \›¯õP £vÁõQ EÒÍuõ GߣuøÚ \›£õºzxU
öPõÒÍÄ®. Aa_¨£vÂÀ SøÓ°¸¨¤ß AøÓU PsPõo¨£õÍ›h®
EhÚi¯õPz öu›ÂUPÄ®.
(2) }»® AÀ»x P¸¨¦ ø©°øÚ ©mk÷© GÊxÁuØS®
AiU÷PõikÁuØS® £¯ß£kzu ÷Ásk®. £h[PÒ ÁøµÁuØS
ö£ß]À £¯ß£kzu ÷Ásk®.
(3) ÷uøÁ¯õÚ ChzvÀ Áøµ£h® ©ØÖ® \©ß£õkPøÍz u¸P.
Instructions : (1) Check the question paper for fairness of printing. If there is any lack of fairness,
inform the Hall Supervisor immediately.
(2) Use Blue or Black ink to write and underline and pencil to draw diagrams.
(3) Draw diagrams and write equations wherever necessary.

£Sv & I / PART - I

SÔ¨¦ : (i) AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 15x1=15

(ii) öPõkUP¨£mkÒÍ |õßS ©õØÖ ÂøhPÎÀ ªPÄ® Hئøh¯
Âøhø¯z ÷uº¢öukzx SÔ±mkhß Âøh°øÚ²® ÷\ºzx
GÊuÄ®.

Note : (i) Answer all the questions.
(ii) Choose the most appropriate answer from the given four alternatives and write
the option code and the corresponding answer.

8363 2

1. ¼¨-¤k Cµmøh AkU-Põ-Ú-x __________ uß-ø©-²-øh-¯x.
(A) }º ¸®-¦® ©Ø-Ö® }º öÁÖU-S®
(B) }º ¸®-¦®
(C) öÁÎa `Ç-ø»¨ ö£õ-Özx Auß ußø© Aø©-Q-Óx.
(D) }º öÁÖU-S®
The Lipid bilayer is __________ in nature.
(a) Hydrophilic and Hydrophobic
(b) Hydrophilic
(c) the nature depends on the immediate environment
(d) Hydrophobic

2. ¤z-u¨ø£ Gß-£x J¸ __________ ÁiÁ ø£ BS®.
(A) •møh Ái-Á® (B) ÷£›U-Põ´
(C) SÇõ´ Ái-Á® (D) ÷PõÍ Ái-Á®
Gall bladder is a __________ shaped sac.
(a) Oval (b) Pear
(c) Tubular (d) Globular

3. £õÀ ¦µ-u®, £õ-µõ-÷P-]-÷Úm-hõP ©õ-Ö-Á-uØS Põ-µ-n® :
(A) öá»õm-i-÷Úì (B) ÷Pìm-›U-]ß
(C) ö£¨-]ß (D) öµÛß
__________ is responsible for the conversion of milk protein to Paracaseinate.
(a) Gelatinase (b) Gastricsin
(c) Pepsin (d) Rennin

4. Cµzua-\ºU-Pøµ Gß-£-x __________.
(A) SÐU-÷Põì (B) _U-÷µõì
(C) ¤µU-÷hõì (D) »õU-÷hõì
Blood sugar is __________.
(a) Glucose (b) Sucrose

(c) Fructose (d) Lactose

3 8363

5. DOPA Gß-£-x __________.
(A) øhøím-µõUê ¤øÚÀ A»-øÚß
(B) iøím-µõUê ¤øÚÀ A»-øÚß
(C) jøím-÷µõ ¤øÚÀ A»-øÚß
(D) øhøím-µõUê ¤øÚÀ A]m-÷hm
DOPA is __________.
(a) Dihydroxy phenyl alanine
(b) Dehydroxy phenyl alanine
(c) Dehydro phenyl alanine
(d) Dihydroxy phenyl acetate

6. öPõ-»ì-i-µõ-¼ß ö£Ö-v-¯õ-Ú-x __________.
(A) øÁm-h-ªß E (B) øÁm-h-ªß A
(C) øÁm-h-ªß D (D) øÁm-h-ªß C
__________ is a derivative of Cholesterol.
(a) Vitamin E (b) Vitamin A
(c) Vitamin D (d) Vitamin C

7. ©µ-¦z-u-P-ÁÀ-PøÍ DNA ¼-¸¢x ø\m-÷hõ-¤Íõ-\z-vØS öPõsk ö\À-¾® RNA
__________ GÚ AøÇU-P¨-£-k®.
(A) yx RNA (B) ›÷£õ-÷\õ-©À RNA
(C) hn RNA (D) Phzx RNA
The RNA which carries the genetic information from the DNA to the cytoplasm is called __________.
(a) messenger RNA (b) ribosomal RNA
(c) hn RNA (d) transfer RNA

8. RÌU-Ps-h-ÁØ-ÔÀ G¢u ö|õv SøÓ-£õk Põ-µ-n-©õP Põ-»U-÷hõ-^-ª-¯õ E¸-Áõ-Q-Óx ?
(A) Põ-»U-÷hõì&1&-£õì-÷£m ³›-øhÀ iµõßì-ö£-÷µì
(B) S-ÐU-÷Põ-øP-÷Úì
(C) £õì-÷£õ SÐU-÷Põ ª³-÷hì
(D) Põ-»U-÷hõ øP÷Úì
Which of the following enzyme deficiency causes Galactosemia ?
(a) galactose-1-phosphate uridyl transferase
(b) gluco kinase
(c) phosphoglucomutase
(d) galacto kinase

8363 4

9. Ps-P-ÎÀ HØ-£-k® {Ó-ªU SøÓ-£õk ¤ß-Á-¸-©õÖ AøÇU-P¨-£-k-Q-Ó-x.
(A) AÀ-Põ¨-÷hõ-Þ-›-¯õ (Alkaptonuria)
(B) ÂÈ-°-ÝÒ AÀ-¤-Û-\® (Ocular albinism)
(C) ï÷©õ-¤-¼-¯õ (Hemophilia)
(D) ÂÈ-`Ì AÀ-¤-Û-\® (Oculo-cutaneous albinism)
The decreased pigmentation in eyes is called as __________.
(a) Alkaptonuria
(b) Ocular albinism
(c) Hemophilia
(d) Oculo-cutaneous albinism

10. NADH iøím-µ-á-÷Ú-êß Cønz-öuõ-Sv __________.
(A) FAD (B) FMN (C) NADPH (D) NADH
The prosthetic group of NADH Dehydrogenase is :
(a) FAD (b) FMN (c) NADPH (d) NADH

11. Bß-i-£õ-i-PÍõÀ A[-R-P-›U-P¨-£mk Bß-i-öáß Cøn-²® Bß-i-£õ-i-°ß £S-v
Gx ?
(A) G¤-÷hõ¨ (B) £õ-µõ-÷hõ¨
(C) ÷í¨-÷hß (D) AU-›-÷hõ¨
What is the name of the region of antibody which recognizes and binds to antigen ?
(a) Epitope (b) Paratope
(c) Hapten (d) Agretope

12. J¸ ö|õ-v-°ß ÷£õmi uk¨-£õß ö£õ-x-Áõ-P __________.
(A) ÂøÚ¨-ö£õ-¸-Îß Ái-Á-ø©¨ø£ Jz-ux
(B) J¸ Av-P ÂøÚ-v-Óß Eøh-¯ ÷\º-©®
(C) }›À Pøµ-¯õz-ußø© Eøh-¯-x
(D) Hg2+ AÀ-»x Pb2+ ÷£õßÓ J¸ E÷»õ-P A¯Û
A competitive inhibitor of an enzyme is usually __________.
(a) structurally similar to the substrate
(b) a highly reactive compound
(c) water insoluble
(d) a metal ion such as Hg2+ or Pb2+

5 8363

13. §mk \õ uz-x-Ázøu E¸-ÁõU-Q-¯-Áº __________.
(A) ÷Põè-÷»sm (B) iU-\õß
(C) ø©U-P-¼ì ö©ß-hß (D) ¤è-åº
Lock and Key theory was proposed by __________.
(a) Koshland (b) Dixon
(c) Michaelis Menten (d) Fischer

14. RÌU-Ps-h-ÁØ-ÖÒ Gx ÷£s-h-ªU (Pandemic) ÷|õ´ ?
(A) ÷µ¤ì (B) AIDS (C) ¤÷ÍU (D) \õ-uõ-µn \Î
Which one of the following disease is a Pandemic disease ?
(a) Rabies (b) AIDS (c) Plague (d) Common cold

15. ¤ß-Á-¸-Á-Ú-ÁØ-ÖÒ Gx J÷µ J¸ G»Um-µõøÚ HØ-ÖU- öPõÒ-Q-Óx ?
(A) FMN (B) ø\m-÷hõ-S-÷µõ® b
(C) FAD (D) xøn-ö|õ-v Q
Which of the following accepts only one electron ?
(a) FMN (b) Cytochrome b
(c) FAD (d) Coenzyme Q

£Sv & II / PART - II

SÔ¨¦ : H÷uÝ® BÖ ÂÚõUPÐUS Âøh¯ÎUPÄ®. ÂÚõ Gs 24 &US
Pmhõ¯©õP Âøh¯ÎUPÄ®. 6x2=12
Note : Answer any six questions. Question No. 24 is Compulsory.

16. uø\ ö|QÌÄ £ØÔ GÊ-xP.
Write about Tonicity.

17. Sh-¼-¯U-P® Gß-ÓõÀ GßÚ ?
What do you mean by Motility ?

18. QøÍU-÷Põ-öá-Û-]ì Gß-ÓõÀ GßÚ ?
What is Glycogenesis ?

8363 6

19. øu÷µõ-]ß GÆ-ÁõÖ ÷hõ-£õ-S-³-÷Úõ-ÚõP ©õØ-Ó¨-£-k-Q-Óx ?
How is Tyrosine converted to Dopaquinone ?

20. öPõ-»ì-j-µõ-¼ß Aø©¨ø£ ÁøµP.
Draw the structure of Cholesterol.

21. ï÷©õ-¤-¼-¯õ-Âß ÁøP-P-øÍ GÊ-x-P.
Write the types of Hemophilia.

22. Cønzuk¨-£õß-PÒ £ØÔ SÔ¨¦ ÁøµP.
Write a note on Uncouplers.

23. ys-h¨-£mh ö£õ-¸¢-x-uÀ ©õ-v› Gß-ÓõÀ GßÚ ?
What is Induced Fit Model theory ?

24. I¢x ÁøP-¯õÚ Cª-÷Úõ-S÷Íõ-¤-¼ß-P-Îß ö£¯º-PøÍ GÊ-xP.
Write the names of five types of immunoglobulins.

£Sv & III / PART - III

SÔ¨¦ : H÷uÝ® BÖ ÂÚõUPÐUS Âøh¯ÎUPÄ®. ÂÚõ Gs 33 &US
Pmhõ¯©õP Âøh¯ÎUPÄ®. 6x3=18

Note : Answer any six questions. Question No. 33 is Compulsory.

25. \Æ-Åk £µ-Á-¼ß E°-›-¯À •U-Q-¯z-x-Ázøu GÊ-x-P.
Write the biological importance of Osmosis.

26. EªÌ-}-›ß Cø¯-¦ ©Ø-Ö® ö\¯À-£õ-k-PøÍ GÊ-x-P.
Write the composition and functions of Saliva.

27. ö\À ÂÊ[-S-u-¼À {P-Ê® £À-÷ÁÖ ö\¯À-•-øÓ-PÒ ¯õøÁ ?
What are the processes involved in Phagocytosis ?

7 8363

28. §gø\ öuõØÖ £ØÔ ]Ö-S-Ô¨¦ Áøµ-P.
Write short notes on fungal infections.

29. öPõʨ¦ Aª» BU-]-á-÷ÚØ-Ó® £ØÔ ]Ö-S-Ô¨¦ Áøµ-P.
Write short notes about oxidation of fatty acids.

30. PCR ö£¸U-Pz-vÀ {P-Ê® £i-{-ø»-PøÍ GÊ-xP.
Write the steps involved in PCR amplification.

31. ÷h \õUì ÷|õ-°ß Põ-µ-n® £ØÔ GÊ-xP.
Write about the causes of Tay-Sachs disease.

32. G»Um-µõß Phzx \[-Q-¼-°ß Aøn-Ä&II £ØÔ GÊ-xP.
Write about Complex-II of Electron Transport Chain.

33. }›-ÈÄ ÷|õ-°ß AÔ-S-Ô-PÒ £ØÔ GÊ-xP.
Write about the symptoms of Diabetes Mellitus.

£Sv & IV / PART - IV
SÔ¨¦ : AøÚz-x ÂÚõU-P-ÐUS® Âøh¯ÎUPÄ®. ÷uøÁ-¯õÚ Ch[-P-ÎÀ £h®
ÁøµP. 5x5=25

Note : Answer all the questions. Draw the diagrams wherever necessary.

34. (A) J¸ \Æ-Âß ¦µ-u Cø¯-¦ £ØÔ GÊ-xP.
AÀ»x
(B) £i- ö ¯- k z- u À {PÌ- ø Á¨ ö£õ- ¸ zx ¦÷µõ- ÷ P- › - ÷ ¯õmk- P Ò ©Ø- Ö ®
³÷P-›-÷¯õm-k-PøÍ J¨-¤-kP.
(a) Write about the Protein Composition of a membrane.
OR

(b) Compare Prokaryotes and Eukaryotes with respect to Transcription.

8363 8

35. (A) Cøµ¨-ø£-°À ¦µ-u[-P-Îß ö\›z-uÀ £ØÔ GÊ-xP.
AÀ»x
(B) Áõß&-Q-ŸUì ÷|õ-°ß Põ-µ-n® ©Ø-Ö® AÔ-S-Ô-PÒ £ØÔ ÂÍU-SP.
(a) Write about the digestion of proteins in Stomach.
OR
(b) Explain about the causes and symptoms of Von Gierke disease.

36. (A) TCA _ÇØ-]-°À EÒÍ £i-{-ø»-PøÍ ÂÁ-›U-P-Ä®.
AÀ»x
(B) G»Um-µõß Phz-xa- \[-Q-¼-°À {P-Ê® G»Um-µõß-P-Îß £õ´-uø» £h®
Áøµ¢x ÂÍU-SP.
(a) Describe the steps involved in TCA cycle.
OR
(b) Explain with diagram about the flow of electrons in Electron Transport Chain.

37. (A) i›¨-÷hõ-÷£ß GÆ-ÁõÖ {¯õ-]-ÚõP ©õØ-Ó¨-£-k-Q-Óx ?
AÀ»x
(B) ø©U-P-¼ì ö©ß-hß (MM) \©ß-£õm-øhz u¸-Â.
(a) How is Tryptophan converted to Niacin ?
OR
(b) Derive Michaelis-Menten (MM) equation.

38. (A) ¼¨-¤-k-P-Îß E°›¯À ö\¯À-£õ-k-PøÍ £m-i-¯-¼-kP.
AÀ»x
(B) EhØ-Põ¨¦ ‰»z-vß Aø©¨ø£ £h® Áøµ¢x ÂÍU-SP.
(a) List the biological functions of Lipids.
OR

(b) Explain about the structure of antibody with diagram.

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