TN 12th Question Paper 2026 Biology

FOR TN 12TH EXAM PREPARATION

TN 12th 2026
Question Paper ·
Biology
EXAM YEAR TYPE SUBJECT

TN 12th 2026 Question Paper Biology

Notes · Sample Papers · Previous Year Papers · Mock Tests

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No. of Printed Pages : 11
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9027
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!9027Biology! PART - III
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: 3.00 ] [ : 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®
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(2) }»® AÀ»x P¸¨¦ ø©°øÚ ©mk÷© GÊxÁuØS®
AiU÷PõikÁuØS® £¯ß£kzu ÷Ásk®. £h[PÒ ÁøµÁuØS
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Instructions : (1) Check the question paper for fairness of printing. If there is any lack of fairness,

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inform the Hall Supervisor immediately.

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Use Blue or Black ink to write and underline and pencil to draw diagrams.

SÔ¨¦ : £Sv& (E°›&uõÁµÂ¯À), £Sv& (E°›&»[Q¯À) uÛzuÛ ÂøhzuõÎÀ
I II

Âøh¯ÎUPÄ®.
Note : Candidate should answer Part-I (Bio-Botany) & Part-II (Bio-Zoology) in separate answer-

books.

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£Sv - I (E°›&uõÁµÂ¯À) / PART - I (BIO-BOTANY)

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(©v¨ö£sPÒ : 35) / (Marks : 35)

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a (i) AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 8x1=8

(ii) öPõkUP¨£mkÒÍ |õßS ©õØÖ ÂøhPÎÀ ªPÄ® Hئøh¯
Âøhø¯z ÷uº¢öukzxU 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.

[ v¸¨¦P / Turn over

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9027 2

1. K[Szußø© ©øÓzu¼ß ÂQu©õÚx :

(A) 9 : 3 : 4 (B) 9 : 3 : 3 : 1 (C) 9 : 6 : 1 (D) 12 : 3 : 1

The dominant epistasis ratio is :

(a) 9 : 3 : 4 (b) 9 : 3 : 3 : 1 (c) 9 : 6 : 1 (d) 12 : 3 : 1

2. ""\kv ©õØÓU ÷Põm£õmøh'' •ßö©õÈ¢uÁº :

(A) C.B. ¤›máì (B) T. ÷£õ÷Á›
(C) W.S. \mhß (D) î²÷Põ j Æ›ì
“Mutation theory” was proposed by :

(a) C.B. Bridges (b) T. Boveri

(c) W.S. Sutton (d) Hugo de Vries

3. uÛ ö\À ¦µu EØ£zv°À £¯ß£kzu¨£k® £õ] :

(A) ÷Psihõ ²mi¼ì (B) S÷ÍõöµÀ»õ
(C) AÀP¼ãßì (D) ö\À¾÷»õ÷©õÚõì
The alga used in the production of Single Cell Protein is :

(a) Candida utilis (b) Chlorella

(c) Alcaligenes (d) Cellulomonas

4. ußÚÊzuP»øÚ¨ £¯ß£kzv ~sq°º }UP® ö\´ÁuØS ___________

{ªh[PÒ ©ØÖ® öÁ¨£{ø»°À ÷©ØöPõÒͨ£kQÓx
__________ .

(A) 15 •uÀ 30 {ªh[PÒ ©ØÖ® 1218 C

(B) 10 •uÀ 30 {ªh[PÒ ©ØÖ® 1258 C

(C) 10 •uÀ 20 {ªh[PÒ ©ØÖ® 1218 C

(D) 15 •uÀ 20 {ªh[PÒ ©ØÖ® 1258 C

The time duration for sterilization process by using autoclave is ___________ minutes and

the temperature is __________.

(a) 15 to 30 minutes and 1218 C

(b) 10 to 30 minutes and 1258 C

(c) 10 to 20 minutes and 1218 C

(d) 15 to 20 minutes and 1258 C

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5. uÛzx ÁõÊ® ø|mµáøÚ {ø»¨£kzx® ©ØÖ® A÷\õ»õ GßÓ }º ö£µo°À
J¸[S°›¯õP ÁõÊ® \¯÷Úõ£õUj›¯® :
(A) S÷ÍõöµÀ»õ (B) |õìhõU
(C) øµ÷\õ¤¯® (D) AÚ¥Úõ
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A free living nitrogen fixing cyanobacterium which can also form symbiotic association with

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the water fern Azolla.

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(a) Chlorella (b) Nostoc

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(c)

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Rhizobium (d) Anabaena

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RÌPshÁØÔÀ Gx ]øuÄ ö\¯À•øÓ AÀ» ?
(A) Áͺ©õØÓ® (B) ÁiuÀ (C) xqUPõuÀ (D) ]øu©õØÓ®
Which of the following is not the mechanism of decomposition ?

(a) Anabolism (b) Eluviation (c) Fragmentation (d) Catabolism

7. K÷\õÛß ui©øÚ AÍÂk® A»S
o m ___________.

c
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(A) hõ¨\ß (B) áüÀ
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(C) (D) Q÷»õ

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The unit for measuring Ozone thickness.

(a) Dobson (b)

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Joule (c) Watt (d) Kilo

8. RÌPsh G¢u¨ £°º CµP® Auß ÷|õ´ GvºUS® vÓÝhß \›¯õP
ö£õ¸¢v²ÒÍx ?
CµP[PÒ ÷|õ´ GvºUS® vÓß
(A) §\õ _¨µõ - ªÍPõ´ ÷u©À øÁµì
(B) §\õ ÷Põ©À £õUj›¯ AÊPÀ m
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-

om §\õ _ÁºÛ®
c. (D)
(C) - P¸¨¦ AÊPÀ
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Which one of the following crop varieties correctly matches with its resistance to a disease ?

ag Variety Resistance to disease

(a) Pusa Shubhra - Chilli mosaic virus

(b) Pusa Komal - Bacterial blight

(c) Pusa Swarnim - Black rot

(d) Pusa Sadabahar - White rust

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¤›Ä & 2 / SECTION - 2

SÔ¨¦ : RÌPõq® ÂÚõUPÎÀ H÷uÝ® |õßS ÂÚõUPÐUS Âøh¯ÎUPÄ®. 4x2=8

Note : Answer any four of the following questions.

9. £ÀTmk AÀ½ÀPÒ – Áøµ¯ÖUPÄ®.
Define Multiple alleles.

10. P¸¨ø£°ß Aø©¨ø£ £h® Áøµ¢x £õP[PøÍU SÔUPÄ®.
Draw the structure of Embryo Sac and label the parts.

11. PøÍUöPõÀ¼ø¯z uõ[S® ußø©²øh¯ £°ºPÎß AÝT»[PÒ CµsiøÚ
GÊxP.
Write any two advantages of Herbicide Tolerant Crops.

12. RÌPsh uµÄPøÍU öPõsk EnÄ \[Q¼ø¯ E¸ÁõUSP.
£¸¢x, uõÁµ[PÒ, uÁøÍ, £õ®¦, öÁmkUQÎ
Construct the food chain with the following data.

Hawk, Plants, Frog, Snake, Grasshopper

13. P»¨¦Özu¼ß £À÷ÁÖ ÁøPPøÍU SÔ¨¤kP.
Mention the different types of hybridization.

14. "ø£°kuÀ' GßÓõÀ GßÚ ?
What is 'Bagging' ?

¤›Ä & 3 / SECTION - 3

SÔ¨¦ : RÌUPõq® ÂÚõUPÎÀ H÷uÝ® ‰ßÖ ÂÚõUPÐUS Âøh¯ÎUPÄ®.
ÂÚõ Gs &US Pmhõ¯©õP Âøh¯ÎUPÄ®.
19 3x3=9

Note : Answer any three of the following questions. Q. No. 19 is compulsory.

15. ©µ£q Áøµ£hzvß £¯ßPøÍ GÊxP.
Write the uses of genetic mapping.

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16. ö£õxÁõP ©ÛuÛß ö\¯À£õkPÒ `ÇÀ ©sh»zvØS GvµõP÷Á EÒÍx. J¸
©õnÁÚõP } `ÇÀ ©sh» £õxPõ¨¤ØS GÆÁõÖ EuÄÁõ´ ?
Generally human activities are against to the ecosystem, where as you a student how will

you help to protect ecosystem ?

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17.
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¦Â öÁ¨£©øhu¼ß ÂøÍÄPÒ ¯õøÁ ?
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What are the effects of Global Warming ?

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18. h¥mhzvß £oPøÍ £mi¯¼kP.
List out the functions of Tapetum.

19. ©µ£q¨ ö£õÔ°¯¼À ÷uøÁ¨£k® ªP •UQ¯ ö|õvPÎß ö£¯ºPøÍ GÊxP.
Name the most important enzymes, required for genetic engineering.

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¤›Ä & 4 / SECTION - 4

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SÔ¨¦ : AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 2x5=10

Note : Answer all the questions.

20. (A) £_[PoP ©µ£q \õº¢u £õµ®£›¯zøu GkzxUPõmkhß öÁÎ öPõnºP.
AÀ»x
(B) EøÓSκ £õxPõ¨¦ £ØÔ ÂÍUSP.
(a) Bring out the inheritance of chloroplast gene with an example.

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OR

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(b) Explain about Cryopreservation.

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(B) ©g\Îß £¯ßPøÍ ÂÁ›UPÄ®.
(a) Tabulate different interactions of plants.

OR

(b) Describe the uses of Turmeric.

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£Sv & II (E°›&»[Q¯À) / PART - II (BIO-ZOOLOGY)

(©v¨ö£sPÒ & 35) / (Marks : 35)

¤›Ä & 1 / SECTION - 1

SÔ¨¦ : (i) AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 8x1=8

(ii) öPõkUP¨£mkÒÍ |õßS ©õØÖ ÂøhPÎÀ ªPÄ® Hئøh¯
Âøhø¯z ÷uº¢öukzxU 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.

1. PßÛ CÚ¨ö£¸UPzvøÚ •uß•u¼À PshÔ¢uÁº ___________.

(A) £õº ©ØÖ® ö£ºmµ® (B) B¤µPõ® iµ®¨Î

(C) áõß ÷Põm÷hõ (D) \õº»ì £õÚm
Parthenogenesis was first discovered by :

(a) Barr and Bertram (b) Abraham Trembley

(c) John Cotto (d) Charles Bonnet

2. Bsm÷µõáß CønĨ ¦µuzøu EØ£zv ö\´£øÁ :

(A) ö\º÷hõ¼ ö\ÀPÒ (B) ½iU ö\ÀPÒ

(C) ¤m³mh› _µ¨¤ (D) øí÷£õu»õ©ì
The Androgen Binding Protein (ABP) is produced by :

(a) Sertoli cells (b) Leydig cells

(c) Pituitary gland (d) Hypothalamus

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3. ö£õ¸zxP :

(1) C¯ØøP •øÓ (i) Cu-T

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(2) uk¨¦ •øÓ (ii) ¢xSÇÀ uøh
o m m
c
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(3) AÖøÁ ]Qaø\
e m (iii) P¸zuøh EøÓ
l a
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EÒgP¸¨ø£a
a
(4) \õuÚ® (iv) Põ» CøhöÁÎ

(A) (1) - (ii), (2) - (iv), (3) - (iii), (4) - (i)

(B) (1) - (ii), (2) - (iii), (3) - (iv), (4) - (i)

(C) (1) - (iv), (2) - (iii), (3) - (ii), (4) - (i)
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(D) (1) - (iv), (2) - (ii), (3) - (iii), (4) - (i)
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Match the following. a
(1) Natural method (i) Cu-T

(2) Barrier method (ii) Vasectomy

(3) Surgical method (iii) Condom

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(4) Intra Uterine Device (iv) Periodic Abstinence

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las (a) (1) - (ii), (2) - (iv), (3) - (iii), (4) - (i)

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ag (b) (1) - (ii), (2) - (iii), (3) - (iv), (4) - (i)

(c) (1) - (iv), (2) - (iii), (3) - (ii), (4) - (i)

(d) (1) - (iv), (2) - (ii), (3) - (iii), (4) - (i)

M [ v¸¨¦P / Turn over

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9027 8

4. RÌUPsh G¢u ¦Óz÷uõØÓ \¢uvPÒ, ö£Ø÷ÓõºPÒ A×B &PÐUQøh÷¯ ¤ÓUP
\õzv¯® Esk ?
(A) AB ©mk® (B) A ©ØÖ® B ©mk®
(C) A, B, AB ©ØÖ® O (D) A, B ©ØÖ® AB ©mk®
Which of the following phenotypes in the Progeny are possible from the parental combination

A×B ?

(a) AB only (b) A and B only

(c) A, B, AB and O (d) A, B and AB only

5. ¦µu EØ£zv°À £[÷PØS® ö©õzu Aª÷Úõ Aª»[PÎß GsoUøP :

(A) 20 (B) 21 (C) 22 (D) 19

The total number of amino acids involved in protein synthesis are :

(a) 20 (b) 21 (c) 22 (d) 19

6. ©ÛuÛÀ EÖ¨¦ ©õØÖ AÖøÁ ]Qaø\°ß ÷£õx uµ¨£k® ÷|õ´ uk¨£õØÓÀ
JkUQ ©¸¢x Gx ?
(A) öhmµõø\UQÎß (B) ø\U÷Íõì÷£õ›ß -A

(C) ö£Û]¼ß (D) ì÷hmißPÒ
Which immunosuppressant drug is given during organ transplantation in humans ?

(a) Tetracycline (b) Cyclosporin-A

(c) Penicillin (d) Statins

7. •uß •u¼À ©¸zxÁ ©µ£q ]Qaø\ ‰»® {Áºzv ö\´¯¨£mh ÷|õ´ :

(A) }º©zv_ AÇØ] (B) G´mì
(C) ¦ØÖ÷|õ´ (D) SCID

The first clinical gene therapy was done for the treatment of :

(a) Cystic fibrosis (b) AIDS

(c) Cancer (d) SCID

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8. TØÖ :

öÁ¨£ ©sh»¨ £SvPÎÀ {»Ä® _ØÖa`ÇÀ ußø©PÒ E°›Ú[PÎß
]ØÔÚ©õUPÀ ©ØÖ® £ÀÁøPz ußø©USa \õuP©õP EÒÍÚ.
Põµn® :

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£¸Á Põ»®, um£öÁ¨£{ø», Dµ¨£u®, JÎUPõ»® HÓUSøÓ¯ {ø»¯õPÄ®
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EP¢uuõPÄ® EÒÍx.
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(A) TØÖ \›,em l a
l as Põµn® uÁÖ.
ag
ag ©ØÖ® Põµn® Cµsk® \›, Põµn® TØøÓ \›¯õP ÂÍUSQÓx
(B) TØÖ .

(C) TØÖ ©ØÖ® Põµn® Cµsk® uÁÖ.
(D) TØÖ ©ØÖ® Põµn® Cµsk® \›, Põµn® TØøÓ \›¯õP ÂÍUPÂÀø» .

Assertion :

The environmental conditions of the tropics are favourable for speciation and diversity of

organisms.

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Reason :

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The climate seasons, temperature, humidity and photoperiod are more or less stable and

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congenial.

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(a)

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Assertion is true, but Reason is false.

(b) Both Assertion and Reason are true and Reason explains Assertion correctly.

(c) Both Assertion and Reason are false.

(d) Both Assertion and Reason are true but Reason is not the correct explanation of

Assertion.

¤›Ä &
o m 2 / SECTION - 2

m . c
c. o : RÌPõq® ÂÚõUPÎÀ H÷uÝ® |õßS ÂÚõUPÐUS Âøh¯ÎUPÄ®.
SÔ¨¦
s e m 4x2=8

e m l a
s
Note : Answer any four of the following questions.

l a ag
ag 9. CǨ¦ «mhÀ & Áøµ¯ÖUPÄ®.
Define Regeneration.

10. CÚ¨ö£¸UP xøn öuõÈÀ ~m£® GßÓõÀ GßÚ ?
What is Assisted Reproductive Technology (ART) ?

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9027 10

11. S÷µõ÷©õ÷\õ® öuõS¨¦ Áøµ£hzvß H÷uÝ® Cµsk £¯ßPøÍ GÊxP.
Write any two applications of Karyotyping.

12. ©Ûu CÚzvß £›nõ©z ÷uõØÓzvß {ø»PøÍ RÌ÷|õUS Á›ø\°À
Á›ø\¨£kzxP.
Bìmµ÷»õ¤zvPì → ÷íõ÷©õ HµUhì → ÷íõ÷©õ ÷\¨¤¯ßì →
µõ©õ¤zvPì → ÷íõ÷©õ íõ¤¼ì .

Rearrange the descent in human evolution.

Australopithecus → Homo erectus → Homo sapiens → Ramapithecus → Homo habilis.

13. RÌUPsh £iö¯kzuÀ A»QÀ A ©ØÖ® GÚU SÔUP¨£mkÒÍÁØøÓ GÊxP.
B

Name the parts marked A and B in the given transcription unit.

14. Ci÷¯õöÚÀ»õ \õUøP¯ß]ì £ØÔ ]Ö SÔ¨¦ GÊxP.
Write a short note on Ideonella sakaiensis.

¤›Ä & 3 / SECTION - 3

SÔ¨¦ : GøÁ÷¯Ý® ‰ßÖ ÂÚõUPÐUS Âøh¯ÎUPÄ®. ÂÚõ Gs 19 &US
Pmhõ¯©õP Âøh¯ÎUPÄ®. 3x3=9

Note : Answer any three of the following questions. Q. No. 19 is compulsory.

15. ^®£õÀ GßÓõÀ GßÚ ? Auß •UQ¯zxÁzøu GÊxP.
What is Colostrum ? Write its significance.

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16. ©µ¤¯À |PºÄ GßÓõÀ GßÚ ? AuÛß £›nõ© uõUP® ¯õx ?
What is genetic drift ? What is its impact on evolution ?

17. EhÀö\À ©µ£q ]Qaø\ ©ØÖ® CÚaö\À ©µ£q ]Qaø\ ÷ÁÖ£kzxP.
m
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Differentiate between somatic cell gene therapy and germline gene therapy.

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em CǨ¤ØPõÚ H÷uÝ® ‰ßÖ Põµn[PøÍ GÊxP.las
18.

l as
E°›¯ £ÀÁøPzußø©°ß
ag
ag
Write any three causes for biodiversity loss.

19. Rh öPõsh uõ´,
−
öPõsh P¸øÁ öPõsi¸US® ÷£õx, Hß Bßi
Rh
+
D

Gvºö£õ¸Ò AÎUP¨£h ÷Ásk® ?
− +
Why should anti D antibodies be administered when a Rh mother carries a Rh foetus ?

¤›Ä & 4 / SECTION - 4

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SÔ¨¦ : AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 2x5=10

Note :

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Answer all the questions.

20.
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a £s¦PÒ H÷uÝ® I¢vøÚ GÊxP.
(A) ©µ£qU SÔ±kPÎß ]Ó¨¦¨
AÀ»x
(B) {n}º •ia]ß Aø©¨ø£ ÂÍUSP.
(a) Write any five salient features of genetic code.

OR

(b) Explain the structure of Lymph node.

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om Áͺa] ©õv›PÒ / ÁøÍÄPøÍ ÂÁ›UPÄ®.
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21.

e m (B) J¼ ©õ_£õmiß ÂøÍÄPÒ ¯õøÁ ?
AÀ»x
l as
las ag
ag (a) Describe growth models/curves.

OR

(b) What are the effects of noise pollution ?

- o 0 o -

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