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Tamil Nadu State Board · CLASS 12th · Zoology

TAMIL NADU STATE BOARD CLASS 12 ZOOLOGY 2023

43 questions from this CLASS 12th Zoology paper. Log in as a CLASS 12th student to view solutions.

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Q1 mcq
Competition between species leads to :
  • A. Amensalism
  • B. Extinction
  • C. Symbiosis
  • D. Mutation

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Q2 mcq
__________ is used to lower blood cholesterol level.
  • A. Statins
  • B. Clot buster
  • C. Tetracycline
  • D. Cyclosporin A

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Q3 mcq
Which one of the following is true to gastrulation ?
  • A. Formation of three germ layer embryo from single layer embryo.
  • B. Formation of multicellular structure from zygote.
  • C. Attachment of blastocyst to the uterine wall.
  • D. Formation of specific organs from Primary germ layers.

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Q4 mcq
Which of the following Codon codes for methionine ?
  • A. UUU
  • B. AUG
  • C. AUC
  • D. UAA

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Q5 mcq
ZW-ZZ system of sex determination occurs in :
  • A. Reptiles
  • B. Birds
  • C. Fishes
  • D. All of the above

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Q6 mcq
The golden age of reptiles was :
  • A. Paleozoic era
  • B. Mesozoic era
  • C. Proterozoic era
  • D. Cenozoic era

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Q7 mcq
__________ was the first human like being.
  • A. Ramapithecus
  • B. Homo erectus
  • C. Hominids
  • D. Australopithecus

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Q8 mcq
Animals that can move from Fresh water to Sea water :
  • A. Catadromous
  • B. Stenothermal
  • C. Anadromous
  • D. Eurythermal

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Q9 mcq
The first ejaculation of the semen is __________.
  • A. Orchidectomy
  • B. Infertility
  • C. Spermarche
  • D. Azoospermia

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Q10 mcq
Exo-erythrocytic schizogony of Plasmodium takes place in :
  • A. Stomach
  • B. RBC
  • C. Liver
  • D. Leucocytes

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Q11 mcq
The male sex hormone testosterone is secreted from :
  • A. Epididymis
  • B. Sertoli cells
  • C. Prostate gland
  • D. Leydig cell

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Q12 mcq
Dodo, Passenger pigeon and Steller’s sea cow have b ecome extinct due to __________.
  • A. Habitat Loss
  • B. Over exploitation
  • C. Shifting cultivation
  • D. Habitat fragmentation

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Q13 mcq
Allergy involves :
  • A. IgA
  • B. IgE
  • C. IgM
  • D. IgG

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Q14 mcq
The highest DDT concentration in aquatic food chain shall occur in :
  • A. Cell
  • B. Seagull (Fish eating birds)
  • C. Phytoplankton
  • D. Crab

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Q15 mcq
The mode of sexual reproduction in bacteria is by :
  • A. Conjugation
  • B. Formation of gametes
  • C. Zoospore formation
  • D. Endospore formation

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Q16 short answer 2 marks
What is Plasmotomy ?

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Q17 short answer 2 marks
Differentiate spermiogenesis and spermatogenesis.

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Q18 short answer 2 marks
What is Mayer-Rokitansky Syndrome ?

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Q19 short answer 2 marks
What is Lyonisation ?

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Q20 short answer 2 marks
What are Okazaki fragme

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Q21 short answer
What is bio-remediation ?

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Q22 short answer
“Red data book” - What do you know about it ?

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Q23 short answer
Define Eutrophication.

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Q24 short answer
Vaccine is not produced against Chickenpox. Why ?

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Q25 short answer
How does juvenile phase differ from reproductive phase ?

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Q26 short answer
Draw a labeled sketch of a spermatozoan.

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Q27 short answer
Differentiate tubectomy and vasectomy.

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Q28 short answer
Write the salient features of Mutation theory.

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Q29 short answer
What are the functions of immunoglobulin ?

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Q30 short answer
Define Fermentors.

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Q31 short answer
Mention the number of primers required in each cycle of PCR. Write the role of primers and DNA Polymerase in PCR. Name the source organism of the DNA Polymerase used in PCR.

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Q32 short answer
Differentiate Natality and Mortality.

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Q33 short answer
AIDS is not a disease. But it facilitates the attack by other organisms. Why ?

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Q34 long answer 5 marks
Explain the various phases of the menstrual cycle.

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Q35 long answer 5 marks
What is infertility ? Write its causes.

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Q36 long answer 5 marks
Write the salient features of Human Genome Project (HG P).

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Q37 long answer 5 marks
Darwin’s finches and Australian marsupials are suitable examples of adaptive radiation - Justify the statement.

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Q38 long answer 5 marks
What are the steps to be adopted to lead healthy life style ?

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Q39 long answer 5 marks
Write the differences between primary and secondary immune responses.

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Q40 long answer 5 marks
What are the advantages and disadvantages of cloning ?

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Q41 long answer 5 marks
What is population dispersion ? Explain its types.

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Q42 long answer 5 marks
Write the general strategies in conservation.

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Q43 long answer 5 marks
Explain the process of sewage treatment.

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