DAV PUBLIC CHOOLS5, JHARKHAND ZONE (3)

ESTO tneG
FIRST TERMINAL EXAMINATION 2024-25
STD: XII FULL MARKS: 70
SUBJECT: BIOLOGY (044) TIME:3 HOURS
General Instructions:
1. This question paper contains 33 questions. All questions are compuisory.
2. Question paper is divided into five sections
3.
In SECTION-A question number 1to 16 are multiple choice (MCQ) type questions carrying 1mark cach.
4.
n SECTION-B question number 17 to 2l are multiple choice (MCQ) type questions carrying 2marks each.
5. In SECTION-Cquestion number 22 to 28 are multiple choice (MC) type questions carTying 3marks each.
6. In SECTION-D question number 29 to 30 are case based questions carrying 4 marks each. Each question
has subparts with internal choice in one
subpart.
7. ln SECTION-E question number 31 to 33 are long answer (LA) type questions carrying 5 marks each.
There is no overall choice, however, an internal choice has been provided in Iquestion in section-B,
Iquestion in section-C, 2 questions in section-D. and all questions in section-E, a candidate has to attempt
one of the alternatives in such questions.
9. Wherever necessary neat and properly labelled diagrams should be drawn.

SECTION-AMCQ TYPE (1X16=16)

The switching 'on' and 'off of the lac operon in prokaryotes is regulated by
(a) Glucose (b)Galactose
Lactose (d) Fructose
2. Select which of the following criteria must a molecule fulfil to act as a genetic material?
(i) It should not be able to generate its replica.
(ii) It should chemically and structurally be stable.
(iii) It should not allow slow mutation.

(iv) It should be able toexpress itself in the form ofMendelian characters.

(a) (1) and (iv) by()and (iv)
e) (üi) and (iv) (d) (ii) and (iv)
3 Which of the following processes results in the production ef recombinatioD in future generations?
(i) Mutation
(i) Independent assortment during meiosis I
(ii)Independent assortment during meiosis II
(iv)Crossing over of bivalents
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 Choose the correct option: -
(a) (iv) only
(bY) and (iv)
(c) (i), (i) and (i) (d) (i), (), (ii) and (iv)
4 Match the following and choose the correct options
ColumnI Column I
(A)Trophoblast (i) Embedding of
blastocyst in the endometrium
(B) Cleavage ' (ii)Group of cells that would
(C)Inner cell mass
differentiate as embryo
o(ii1) Outer layer of
blastocyst atached to the endrometrium
(D) Implantation ) (iv) Mitotic division of zygote
Options:
(2) A-(ii),B-(i),C-(ii),D-(iv)
(c) A-(ii),B-(1),C-(ii), D-(iv) YA-(i),B-(V),C-(), D-()
5
Diaphragms are contraceptive devices used by the@A-(),B-(v),C-(ii),D-()
females. Choose the correct option from
The statements given below:
(i)) They are introduced into the uterus.
(i)They are placed to cover the cervical
region.
(iii) They act as physical barriers for
sperm entry.
(iv) They act as spermicidal agents.
Choose the correct option:
(a) (i) and (ii)
(b) (i) and (iii)
fe) (ii) and (ii) (d) (ii) and (iv)
6. Match the following list ofbioactive
substances and their roles
Bioactive
Substance Role
A. Statin
(i) Removal of oil stains
B. Cyclosporin A
(ii) Removal of clots from blood vessels
C. Streptokinase
(iii) Lowering of blood vessels
D. Lipase
(iv) Immuno-suppressive agent
Choose the correct match.
(a) A-(i),B-(ii),C-(),D-iv) (b)A-(iv),B-(ii),C-(1),D-(i)
(c) A-(iv),B-(i),C-{i1),D-(ii)
7
(c) A-(ii),B-(iv), C-(ii),D-()
Diseases are broadly gTouped into infectious and non-infectious diseases.
In the list given
(i)) Cancer
below, identify the infectious diseases.
(ii) Influenza (iüi) Allergy (iv) Small pox
(a) (i) and (ii)
(b)(ii) and (iii) (c)(i) and (iv) (d) (i) and (iv)
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 Which of the foilowing glands is laroe sizcd at birth but rcduces in sizc with agcing?
(a) Pineal (b) Pituitary
(e) Thymus (d) Thyroid
9. The microbes commonly uscd in
kitchens are
(a) Lactobaci!lus and Yeast. (b) Penicillium and Yeast
(c) Microspora and E. coli (d) Rhizopus and Lactobacillus
10. Which of the following combination of chromosome numbers represents the corTect sex
determination pattern in honey bees?
(a)Male 32, female 16 (5) Male 16,female 32
(c) Male 31, female 32 (d) Female 32, male 31
11. Which of the following is an example for link species?
(a) Lobe fish (b) Dodo bird (c) Sea weed (Chimpanzee
12. The structure of bilobed anther consists of
.

(a) 2 thecae, 2 sporangia (b)4 thecae, 4 sporangia

(c)4 thecae, 4 sporangia ()2 thecae, 4 sporangia
Question nos. 13 to 16 consists of two statements, Assertion (A)and Reason (R).
selecting the appropriate option given below: - Answer these questions
(A) Both Assertion and Reason are true and Reason is the correct
explanation of Assertion. I3
(B) Both Assertion and Reason are true, but Reason is not the correct
explanationof Assertion.
(C) Assertion is true, but Reason is false..
(D) Assertion is false, but Reason is true.
13. Assertion: The inner cell of blastocyst gets attached to the endometrium during
embryonic
developments in humans.
Reason: The blastomeres in the blastocyst gets arranged into trophoblast and inner cell
mass.
14. Assertion: A patient of ADA deficiency undergoing treatment of gene therapy requires
periodic infusion of genetically engineered lymphocytes.
Reason: Lymphocytes are immortal.
15. ASsertion: Tubectomy is a sterilisation procedure advised for females as a terminal
method.
Reason: In tubectomy, a smallpart of thefallopian tube is removed or tied up blocking
Gamete transport thereby preventing conception.
16. Assertion: A small part of activated sludge is pumped back into aeration tank. q
Reason: It serves as an inoculum.

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SECTION-B
statutory ban on
17.

18.
Give one reason to justify
Mention two functions of the
codon AUG.
aninocentesis.
human bod.
19. State two diferent roles of spleen in
20. Listtwo stepsthat are essential for carrying out
21. Given below is a schematic representation of lac
hybridisation in crop plants and why.
operon:

(a) Identify i and p. Pnle

.b) Name the 'inducer' for
this operon and explain its role.
SECTION- C
22.
Expand and explain the following (3X7=21)
(a) GIFT techniques used in the Test Tube Baby
23. Explain tha --
(b) ZIFT (c) IUI programme:
s of auicial
bisexual flowers (ii) female parent hybridisation
to get improved crop
variety in () plants
24.
How are dominance, producing unisexual flowers. bearing
25.
Draw alabelled co-dominance incomplete
and
dominance patterns of
schematic diagram of a
replication fork showing inheritance fromn each oth
replication of DNA
strands. and continuous
26.
What is adaptive discontinuous
Give an example. radiation? When can adaptive radiation be referred to as
27.
Study the diagram convergent evolution?
showing replication of HIV humans and
accordingly. HV
in
answer the following
questions
Vius tocs
normal cal

Antmal cal asma

membrona
-D (Host col

Cytoptnsm
Now viral genettc
matorial s
Oy the t r u d

are produre

Nuccaus DA
Newdnn

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 (a) What type of virus causes AIDS? Name its genetic material.
OR
List any two waysof transmission of HIV infection in human other than sexua! contact.
(b) Name the enzyme 'B' acting on X' to produce molecule 'C. Name C'.
(c) Name the type of cells the AIDS vinns enters ito after getting in the human tody.
28. (a) Explain founder effect",
(b)State Oparin and Haldane Hypothesis.
(c)List any two factors that can disturb the genetic equilibrium.

SECTION-D
(4X2=8)
29.

Levels
Hormone Luteinising Follicle stimulating
Pituitary hormone(LH) hormone (FSH)

Menstrual Cycle Days

(a) What is the importance of LH surge?

(b) Menstrual cycles are absent during pregnancy. Why?
OR

Write the name of phases of Menstrual cycle?

(c) Identify the ovarian phases during the menstrual cycle.
(i) 5th day to 12" day of the cycle.
(i) 14" day of the cycle.
OR

Given below is the structure of an antibody.

Atigen bindings

Light
chain

Disuthdobond

Heavy chains

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 rest cf
(a) A boy of ten years had chicken pOX. 7e 1s not expected to hae the same disease îor the
his life. Mention how it is possibie.
(b) Why is secondary immune respcnse 1Hore mtense than tùe primary inmune response In kumans?

(c)Some allergens trigger sneezing and vheezing in human beings. What causes this type of response
by the body?
(d) State the functions of mast cells in allcrgy response.

30. Given below is a figure of a biogas plant.

DungWater C

-Digester

(a) Name the group of organisms and the substrate they act on to produce biogas.
OR

What does it mean, if sewage has high amount of BOD?

(b) Identify the products Aand B and discuss their significance.
(c) What are methanogens? How do they generate biogas?

OR

(a) What is this diagram

(b) Name the parts a, b,
representing?
and c molecule
(c) In the the nucleus. How is the DNA
eukaryotes, the DNA are Organised within
organized in a bacterial cell in absence of a nucleus?

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SECTION-E
31. (5X3=15)
(2) Explain the following phases in the
menstral cvcle of a human female:
())Menstrual phase
(ii) Follicular phase (iüi) Luteal phase
(0) Aproper understanding of menstn1al cuele can beln
immensely in family planning. Do you agree
with the statement?
Provide reasons for your answer.
OR
(2) Explain Polygenic inheritance and Multinle alelism
with thehelp of suitable Examples.
(b) Phenylketonuria is a good
32.
example that explains Pleiotropy". Justy.
(a)Describe the Hershey-Chase experiment. Write the
conclusion they arrived at after The experiment.
OR
(a) Explain the steps of DNA fingerprinting that will help in
processing of the two blood samples A
and B picked up from the crime scene.
33. (a) Secondary treatment of the sewage is also called biological
treatment. Justify this Statement and
explain the process.
OR
Describe the development of Dicot embryo with suitable diagram.

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