Goa Board Class 12 Sample Paper 2023 Biology

Sample Paper
&
Question Paper Pattern
2022
2023

GOA BOARD

To,

The Secretary,

Goa Board of Secondary and Higher Secondary Education,

Alto Betim, Goa

16/05/2022

Subject: New assessment scheme 2022-23 in biology for standard XII

Respected Madam,

I hereby submit following documents pertaining to assessment scheme 2022-23 in Biology for
standard XII.

The document submitted as follows :

1. Syllabus of Biology ( Theory & practical)

2. Semester wise portion in biology
3. Design of question paper for semester 1
4. Design of question paper for semester 2
5. Portion for First Internal Test
6. Portion for Second Internal Test
7. Design of question paper for first / second internal test.
8. Model papers, Answer Keys and Blue Prints for Semester 1 & Semester 2.

Thanking You

Yours faithfully

Mrs.Meeta Bandekar

(convenor)

Syllabus of Biology (Theory )– ClassXII

Unit-VI Reproduction

Chapter-2: Sexual Reproduction in Flowering Plants
Flower structure; development of male and female gametophytes; pollination - types, agencies
and examples; out breeding devices; pollen-pistil interaction; double fertilization; post
fertilization events - development of endosperm and embryo, development of seed and formation
of fruit; special modes- apomixis, parthenocarpy, polyembryony;

Chapter-3: Human Reproduction
Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis
-spermatogenesis and oogenesis; menstrual cycle; fertilization, embryo development up to
blastocyst formation, implantation; pregnancy and placenta formation (elementary idea);
parturition (elementary idea); lactation (elementary idea).

Chapter-4: Reproductive Health
Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs); birth
control - need and methods, contraception and medical termination of pregnancy (MTP);
amniocentesis; infertility and assisted reproductive technologies - IVF, ZIFT, GIFT (elementary
idea for general awareness).

Unit-VII Genetics and Evolution

Chapter-5: Principles of Inheritance and Variation
Heredity and variation: Mendelian inheritance; deviations from Mendelism – incomplete
dominance, co-dominance, multiple alleles and inheritance of blood groups, pleiotropy;
elementary idea of polygenic inheritance; chromosome theory of inheritance; chromosomes and
genes; Sex determination - in humans, birds and honey bee; linkage and crossing over; sex linked
inheritance - haemophilia, colour blindness; Mendelian disorders in humans - thalassemia;
chromosomal disorders in humans; Down's syndrome, Turner's and Klinefelter's syndromes.

Chapter-6: Molecular Basis of Inheritance
Search for genetic material and DNA as genetic material; Structure of DNA and RNA; DNA
packaging; DNA replication; Central Dogma; transcription, genetic code, translation; gene
expression and regulation - lac operon; Human genome project; DNA fingerprinting.

Chapter-7: Evolution
Origin of life; biological evolution and evidences for biological evolution (paleontology,
comparative anatomy); Darwin's contribution, modern synthetic theory of evolution; mechanism
of evolution - variation (mutation and recombination) and natural selection with examples, types
of natural selection; Gene flow and genetic drift; Hardy - Weinberg's principle; adaptive
radiation; human evolution.

Unit-VIII Biology and Human Welfare

Chapter-8: Human Health and Diseases
Pathogens; parasites causing human diseases (malaria, filariasis, ascariasis, typhoid, pneumonia,
common cold, amoebiasis, ring worm) and their control; Basic concepts of immunology -
vaccines; cancer, HIV and AIDS; Adolescence - drug and alcohol abuse.

Chapter-10: Microbes in Human Welfare
Microbes in food processing, industrial production, sewage treatment, energy generation
and microbes as bio-control agents and bio-fertilizers.

Unit-IX Biotechnology and its Applications

Chapter-11: Biotechnology - Principles and Processes
Principles of biotechnology, Tools of Recombinant DNA Technology, Processes of Recombinant DNA
Technology.

Chapter-12: Biotechnology and its Applications
Application of biotechnology in health and agriculture: Human insulin, Molecular Diagnosis,
gene therapy; genetically modified organisms - Bt crops; transgenic animals; biosafety issues, bio
piracy and patents.

Unit-X Ecology and Environment

Chapter-13: Organisms and Populations
Population interactions - mutualism, competition, predation, parasitism; population attributes -
growth, birth rate and death rate, age distribution, Organism and its Environment, Major Abiotic
Factors, Responses to Abiotic Factors, Adaptations.

Chapter-14: Ecosystem
Ecosystems: Patterns, components; productivity and decomposition; energy flow;
pyramids of number, biomass, energy, Ecological Succession and Nutrient Cycles.

Chapter-15: Biodiversity and its Conservation
Biodiversity-Concept, patterns, importance; loss of biodiversity; biodiversity
conservation; hotspots, endangered organisms, extinction, Sacred Groves, biosphere
reserves, national parks, wildlife, sanctuaries.

Mrs. Meeta Bandekar

( Convenor)

Syllabus of Biology Practical –
ClassXII

List of Experiments :

Section A – Physiology Experiment

1) To determine the pH and water holding capacity of garden or paddy field soil.

2) To detect presence of phosphate, nitrate and sulphate salts in paddy field soil.

3) To study B.O.D. of the given sample of pond water.

4) To study the effect of different temperature on the action of salivary amylase on
starch.

5) To study the effect of different pH on the action of salivary amylase on starch.

Section B – Preparation of temporary stained slide

1) Onion root tip for mitosis
2) Onion/Rheo anther for meiosis.

Section C – Identification/Spotting

1) Adaptations in insect pollinated flower (Ocimum/Leucas/Salvia)

2) Adaptations in wind pollinated flower (Maize/Grass)
3) Study of T.S. of Testis (Any vertebrate)

4) Study of T.S. of Ovary (Any vertebrate)
5) Study of V.S. of Blastula (Any vertebrate)

6) Prepared pedigree chart of inability to roll the tongue.

7) Prepared pedigree chart of Widow’s peak.
8) Identification of organisms and symptoms of disease caused.
a. Ascaris
b. Entamoeba
c. Plasmodium
9) Adaptation of plant to dry condition (Suitable specimen to be given)

10) Adaptation of plant to aquatic condition (Suitable specimen to be given)
11) Adaptation of animal to dry condition (Suitable specimen/chart/model to be given)
12) Adaptation of animal to aquatic condition (Suitable specimen to be given)

13) Identification of Homologous organs in plants. (eg. Thorn of bougainvillea and tendrils of
Cucurbita)

14) Identification of Homologous organs in animals.( eg. Fore limbs of frog and Flipper of
turtle/ Wings of bird).

15) Identification of Analogous organs in plants. ( eg . tuber of potato and sweet potato).

16) Identification of Analogous organs in animals. (eg. Wings of bird and butterfly).

Mrs. Meeta Bandekar

( Convenor )

GOA BOARD OF SECONDARY AND HIGHER SECONDARY
EDUCATION
ALTO – BETIM 403521
SEMESTERWISE PORTION IN BIOLOGY
ASSESSMENT SCHEME FOR THE ACADEMIC YEAR 2022-23.
STD: XII

PORTION FOR SEMESTER – 1

Sr No. Units Marks
1. REPRODUCTION
Chapter 2: Sexual Reproduction in Flowering plants 6

2. GENETICS AND EVOLUTION
Chapter 5: Principles of Inheritance and Variations 7
Chapter 7 : Evolution 5

3. BIOTECHNOLOGY
Chapter 11: Biotechnology: Principles and Processes 6
Chapter 12: Biotechnology and its Applications 4

4. BIOLOGY IN HUMAN WELFARE
Chapter 8: Human Health and Diseases 7

ECOLOGY
5. Chapter 13: Organisms and Population 5
Total 40

PORTION FOR SEMESTER – 2

Sr. No. Units Marks
6. REPRODUCTION
Chapter 3: Human Reproduction 6
Chapter 4: Reproductive Health 5

7. GENETICS AND EVOLUTION
Chapter 6: Molecular Basis of Inheritance 7

8. BIOLOGY IN HUMAN WELFARE
Chapter 10: Microbes in Human Welfare 4

9. ECOLOGY
Chapter 14 : Ecosystem 4
Chapter 15: Biodiversity and Conservation 4
Total 30

GOA BOARD OF SECONDARY AND HIGHER SECONDARY
EDUCATION
ALTO – BETIM 403521
DESIGN OF THE QUESTION PAPER FOR SEMESTER 1 (2022-23)

CLASS: XII

TIME: 90 mins SUBJECT: BIOLOGY Max. Marks: 40

The weightage of the distribution of marks over different dimensions of the question paper shall
be as follows:

1. Weightage to learning outcomes

Sr Learning Outcomes Marks Percentage of
No. Marks
1. Knowledge 12 30 %
2. Understanding 16 40 %
3. Application 12 30 %
Total 40 100 %

2. Weightage to difficulty level of Questions

Sr No. Estimated Difficulty Level of Questions Percentage
1. Easy 20 %
2. Average 60 %
3. Difficulty 20 %
Total 100 %

 Question paper will have 40 multiple choice questions (MCQs) as per the chapter
wise marks distribution.
 A question may vary in difficulty level from individual to individual.
 MCQs will have four options A/ B/ C/ D.

Ms. Meeta Bandekar

(Convenor)

GOA BOARD OF SECONDARY AND HIGHER SECONDARY
EDUCATION
ALTO – BETIM 403521
DESIGN OF THE QUESTION PAPER FOR SEMESTER 2 (2022-23)

CLASS: XII

TIME: 90 mins SUBJECT: BIOLOGY MAX. MARKS: 30

The weightage of the distribution of marks over different dimensions of the question paper shall
be as follows:

1. Weightage to learning outcomes

Sr Learning Outcomes Marks Percentage of
No. Marks
1. Knowledge 09 30%
2. Understanding 11 35%
3. Application 07 25 %
4. Skill 03 10 %
Total 30 100 %

2. Weightage to forms of questions:

Sr Form of Questions Marks for each No. of Total
No. Questions Questions Marks
1. Long Answer types --- ---- ---
(LA)
2. Short Answer Type (SA 03 03 09
– I)
3. Short Answer Type (SA 02 06 12
– II)
4. Very Short Answer 01 09 09
Type (VSA)
Total 18 30

3. Expected Time for different types of question would be as follows

Sr No. Forms of Questions Approx. Time No. of Approx. Time
for each Questions for each form of
Question in mins (n) Questions in
(t) mins (n x t)
1. Long Answer types ----- --- -------
(LA)
2. Short Answer Type 10 min 03 3 x 10min = 30
(SA – I)
3. Short Answer Type 07 min 06 6 x 7min = 42
(SA – II)
4. Very Short Answer 02 min 09 9 x 2min = 18
Type (VSA)
Total 18 90 mins

As the total time is calculated on the basis of the number of questions required to
be answered and the length of their anticipated answers. It would, therefore be
advisable for the candidates to budget their time properly by cutting out the
superfluous words and be within the expected time limits.

Scheme of options
(There will be no overall choice. However, there is an internal choice in 01 sub
question of 03 marks & 02 marks category)

4. Weightage to difficulty level of Questions

Sr No. Estimated Difficulty Level of Questions Percentage
1. Easy 30 %
2. Average 50 %
3. Difficulty 20 %
Total 100 %

a. Question paper will have three sections A, B, C.
b. Section A will have 09 questions of 01 mark.( strictly No MCQs)
c. Section B will have 06 questions of 02 marks.
d. Section C will have 03 questions of 03 marks.
e. Question shall be from all the chapters specified above.

f. Total number of questions will be 18.
Ms. Meeta Bandekar
( Convenor)

GOA BOARD OF SECONDARY AND HIGHER SECONDARY
EDUCATION
ALTO – BETIM 403521
ASSESSMENT SCHEME FOR THE ACADEMIC YEAR 2022-23.
STD : XII

FIRST TERM

PORTION FOR FIRST INTERNAL TEST (FORMATIVE TEST)

Sr No. Units Marks
REPRODUCTION
1. Chapter 2: Sexual Reproduction in Flowering plants 7

GENETICS AND EVOLUTION
2. Chapter 5: Principles of Inheritance and Variation 7

ECOLOGY
3. Chapter 13: Organisms and Populations 6
Total 20

PORTION FOR SECOND INTERNAL TEST (FORMATIVE TEST)

Sr. No. Units Marks
BIOLOGY IN HUMAN WELFARE
1. Chapter 8: Human Health and Disease 8

2. BIOTECHNOLOGY
Chapter 11: Biotechnology: Principles and Processes 7
Chapter 12: Biotechnology and its Applications 5
TOTAL 20

DESIGN OF QUESTION PAPER FOR FIRST / SECOND INTERNAL TEST
(FORMATIVE)

The weightage of the distribution of marks over different dimensions of the question paper shall
be as follows:

1. Weightage to learning outcomes

Sr Learning Outcomes Marks Percentage of
No. Marks
1. Knowledge 08 40 %
2. Understanding 06 30 %
3. Application 04 20 %
4. Skill 02 10 %
Total 20 100 %

2. Weightage to forms of questions:

Sr Form of Questions Marks for each No. of Total
No. Questions Questions Marks
1. Long Answer types --- --- ---
(LA)
2. Short Answer Type (SA 03 02 06
– I)
3. Short Answer Type (SA 02 05 10
– II)
4. Very Short Answer 01 04 04
Type (VSA)
Total 11 20

3. Expected Time for different types of question would be as follows

Sr No. Forms of Questions Approx. Time No. of Approx. Time
for each Questions for each form of
Question in mins (n) Questions in
(t) mins (n x t)
1. Long Answer types --- --- ---
(LA)
2. Short Answer Type 10 min 02 2 x 10 min = 20

(SA – I)
3. Short Answer Type 05 min 05 5 x 5 min = 25
(SA – II)
4. Very Short Answer 02 min 04 4 x 2min = 08
Type (VSA)
Total 11 53min

As the total time is calculated on the basis of the number of questions required to
be answered and the length of their anticipated answers. It would, therefore be
advisable for the candidates to budget their time properly by cutting out the
superfluous words and be within the expected time limits.

Scheme of options
(There will be no overall choice. However, there is an internal choice in 01 sub
question of 03 marks category)

4. Weightage to difficulty level of Questions

Sr No. Estimated Difficulty Level of Questions Percentage
1. Easy 30 %
2. Average 50 %
3. Difficulty 20 %
Total 100 %

 Question paper will have three sections A, B, C.
 Section A will have 04 questions of 01 mark.
 Section B will have 05 questions of 02 marks.
 Section C will have 02 questions of 03 marks.
 Question shall be from all the chapters specified above.
 Total number of questions will be 11.

Diagrams for evaluation for 2 nd internal test:
1. Figure 8.4 Structure of an antibody molecule
2. Figure 11.7( a) Simple stirred -tank bioreactor

Ms. Meeta Bandekar
( Convenor)

SECOND TERM

THIRD INTERNAL TEST (INNOVATIVE TEST) (20 MARKS)

(As per Circular No 39 dated 02/08/2021)

Innovative Test of 20 Marks is bifurcated as follows:

1. Practical ------- 10 Marks

 Section A------ Physiology Experiment (4mks)

 Section B ------- Preparation of temporary stained slide (3mks)

 Section C ------- Identification / spotting (3mks)

2. Innovative Methods ------------10 Marks
Guidelines For Innovative Methods as Follows:

 Assessment to be conducted on any topic from syllabus.

 Teachers can use methods like quizzes, ppt, videos, concept maps,
concept flow charts for assessment.

 Teachers are free to make their own innovative methods for
assessment.

Ms. Meeta Bandekar
(Convenor)

Goa Board Of Secondary And Higher Secondary Education
Alto- Betim, Goa
Model question paper
1st Semester- 2022-23
Std: XII Sub: Biology
Time: 90 minutes Max. Marks: 40

Instructions:

1. There are 40 questions in the Question Paper. Each question has FOUR options.
You will have to mark the correct Option in the ANSWER SHEET and NOT in the
question paper.

2. Four Circles are provided infront of each question in the ANSWER SHEET. For
each question, Fill/Darken the circle under the correct option 'A' or 'B' or 'C' or 'D'.

3. If more than one circle is darkened for one question, zero will be awarded for that
question.

4. Each correct answer will be awarded ONE mark. There are No Negative Marks.

1) Which one of the following is a characteristic of Turner's syndrome?
A. It is found in males only
B. It is found in males as well as females.
C. An individual with this disorder shows gynaecomastia
D. An individual with this disorder has 45 chromosomes.

2) Colourblind woman has married a man with normal vision. They have 2 sons and one
daughter. Which pedigree chart shows the correct description?

A.

B.

C.

D.

3) Active immunity is achieved when a child receives…………
A. Polio vaccine
B. Anti Tetanus injection
C. Antivenom to treat snakebite
D. Antibodies from mother through placenta during foetal stage.

4) Which of the following is an example of behavioural adaptation?
A. Migration of certain bird species to escape cold winter.
B. Excretion of concentrated urine by desert animals.
C. Sweating in humans during hot weather.
D. Increase in the number of R.B.Cs in humans after climbing high altitudes.

5) Though there are four types of blood groups in ABO blood grouping system, there are
six genotypes. This is due to …….
A. Polygenic inheritance
B. Multiple allelism
C. Pleiotropy
D. Incomplete dominance.

6) A pro-insulin is different from insulin because……….
A. Pro-insulin has no disulphide bonds
B. Pro-insulin is more active than insulin
C. Pro-insulin is from animals other than human beings.
D. Pro-insulin has C peptide.

7) In the following cross the F1 progeny would be……….
TtYY × TTYy

A. Phenotypically similar to parents
B. 50% would be TtYy and 50% would be TTYy
C. All would be heterozygous dominant for the two traits
D. All would be recessive for the two traits

8) As per the table given below, which options shows correct ploidy.

I. Synergeids 2n

II. Tapetum 2n

III. MMC 3n

IV. Megaspore 1n

A. I and II
B. I and IV
C. II and 1V
D. I and III

9) According to the Big Bang theory of origin of universe the earth was initially ……….
A. A tiny planet
B. A molten mass releasing gases
C. Covered with rocky surface
D. Covered with oceans
10) Identify the following structure.

A. It is a microspore mother cell
B. It is a male gametophyte
C. It is a female gametophyte
D. It is an ovule

11) Black ants show high reproductive fitness and higher intrinsic rate of increase
compared to red ants though both share same resources and habitat. This is due to
………..
A. Ammensalism
B. Commensalism
C. Mutualism
D. Competition

12) Which of the following is not a vector?
A. EcoRI
B. YAC

C. BAC
D. Bacteriophage

13) If hybrids are made into apomicts, the progeny would show …………
A. Segregation of parental characters
B. No seed production
C. Parthenocarpy
D. Same characters as that of parent

14) In PCR, the two DNA strands separate from each other. This is due to the breakdown
of …………
A. Phosphodiester bonds
B. Hydrogen bonds
C. Bonds between N base and sugar
D. Phosphodiester as well as hydrogen bonds.

15) A limit called carrying capacity for a species in a habitat brings about ……
A. S shaped growth curve
B. Exponential growth
C. Enormous population density increase in short time
D. No rise in population density at all

16) Which one of the following is an opioid drug?
A. Charas
B. Crack
C. Heroin
D. Marijuana

17) The purpose of using gel electrophoresis in biotechnology is …………
A. To cut DNA polymer into fragments
B. To join two or more DNA fragments
C. To separate DNA fragments from each other
D. To separate the two DNA strands

18) According to Hardy Weinberg equilibrium the gene pool of a population
undergoes…….
A. No change generation after generation
B. Small changes generation after generation
C. Major changes generation after generation
D. A change only in organisms with short life span

19) To cut the following palindromic sequence into sticky ends, the cut should be between
which two bases of the two strands of DNA?

5 AAGCTT 3

3 TTCGAA 5

A. Between G and C of both the strands
B. Between T and T of one strand and A and A of the other strand
C. Between A and A of both the strands
D. Between C and T of one strand and G and A of other strand

20) A mutant hemoglobin leads to a disorder in human beings where RBCs become sickle

shaped. The mutation changes the codon from………
A. GUG TO GAG
B. GAG TO UAG
C. GUG TO AUG
D. GAG TO GUG

21) Neoplastic growth of about 1.5 cm size found in Mrs. Gupta's pancreas was surgically
removed. It's location and size was detected through…….
A. C. T. Scan
B. ELISA
C. PCR test
D. Blood test

22) Name the transgenic protein used to treat emphysema.
A. α-1-antitrypsin
B. α-lactalbumin
C. α-interferon
D. α- galactosidase

23) Most of the food rich in healthy monounsaturated fats are high in cost. Hence high
oleic acid soybean is a good option for the same nutritional benefit. It is produced by
manipulating and altering its genes. Therefore it is an example of ………..
A. Hybridisation
B. Genetically modified organisms
C. Gene therapy
D. Agrochemical based crops

24) The two pictures shown here indicate……

A. Homology
B. Divergent evolution

C. Convergent evolution
D. Common ancestry

25) Smoking reduces the concentration of heme bound oxygen by……….
A. Increasing CO2 content in blood
B. Increasing the CO content in blood
C. Degrading the hemoglobin in blood

D. Decreasing the R.B.C production.

26) Which statement is true for plasmids?
A. It cannot replicate on its own
B. It is a linear DNA
C. It is cut by exonuclease
D. It is an extra chromosomal matter

27) A microsporangium of a flowering plant in its transverse section is……….
A. Bilobed
B. Dithecous
C. Nearly circular in outline
D. Tetragonal in outline

28) From the given diagrammatic representation of natural selection for a human trait,
what can you conclude? ……

A. Natural selection is disruptive
B. Natural selection is directional.
C. Natural selection does not operate
D. Natural selection is stabilising.

29) Gene A and B are tightly linked and gene X and Y are loosely linked . Which statement
is true in this case?
A. Gene A and B are on the same chromosome but Gene X and Y are on two
separate chromosomes.
B. Gene A and B shows 1.6 % gene recombination frequency and gene X and Y
show 33.2 % gene recombination
C. Gene A and B are distantly located and gene X and Y are closely located on same
chromosome.
D. Gene A and B as well as gene X and Y are located on two separate chromosomes.

30) Match the two columns correctly by selecting one of the following options.

A B

1. Pseudocopulation a. transfers energy
across trophic levels

2. Immigration b. enables organism to
survive and reproduce
in its habitat

3. Adaptation c. occurs by employing
sexual deceit.

4. Predation d. increases the
population density

A. 1- c, 2 - d, 3 - a, 4 -b
B. 1- d, 2 - c, 3 - b, 4 - a
C. 1- c, 2 - d, 3 - b, 4 - a
D. 1 - b, 2- a, 3 - d, 4 - c

31) In a particular plant, the seed shows perisperm. This plant is diploid with 24
chromosomes. Therefore the cells of perisperm have………
A. 12 chromosomes
B. 24 chromosomes
C. 36 chromosomes
D. 48 chromosomes

32) Growth is a result of basal metabolism, activities and physiological functions carried
out by enzymes. Hence mango trees do not grow naturally in Canada and Germany. This
explains the importance of which abiotic factor in geographical distribution of organisms?
A. Water
B. Light
C. Soil
D. Temperature

33) Enzyme protease was used to open the first barrier of a cell and isolate DNA during
biotechnology experiment. The researchers must be working on ………….
A. Human cell
B. Fungal cell
C. Bacterial cell
D. Algal cell

34) Sarika's symptoms include diarrhea with blood and mucus in the stools, fatigue, mild
fever. She is suffering from……

A. Pneumonia
B. Common cold
C. Amoebiosis
D. Ringworm

35) RNAi has been applied successfully in producing which of the following?
A. Bt Cotton plant.

B. Golden rice enriched with vitamin A
C. Human insulin in E.coli
D. Tobacco plant to prevent nematode infestation.

36) A student picked up 15 flowers from a plant to study pollen germination. He discarded
5 flowers as they had only pistils and took the remaining flowers to the laboratory. This
plant must be exhibiting ……………
A. Geitonogamy only
B. Geitonogamy and Xenogamy
C. Autogamy only
D. Autogamy and geitonogamy

37) Which of the following is incorrect about the diagram shown below.

A. It is called H1L2 molecule.
B. It has heavy and light protein chains
C. It is an immunoglobulin
D. It has an antigen binding site.

38) Which organisms originated first on earth in the evolutionary history from the following?
A. Giant ferns
B. Jawless fishes
C. Ichthyosaurs
D. Monocots

39) A test cross was performed on Pisum sativum and the F1 progeny was 50 % tall and
50% dwarf. Which of the following represents the parental generation of this cross?
A. TT × Tt
B. Tt × Tt
C. TT × tt
D. Tt × tt

40) To trap microbes and prevent their entry in our body which of the following play a role?
A. Macrophages
B. Acid in stomach

C. Mucus coating in gastrointestinal tract
D. Saliva in the mouth

-------------------------------------------------------------------------------------------------------------

Goa Board Of Secondary And Higher Secondary Education
Alto- Betim, Goa
Model question paper- Answer key
1st Semester- 2022-23
Class: XII Sub: Biology
Time: 90 minutes Max. Marks: 40

1) D

2) C

3) A

4) A

5) B

6) D

7) A

8) C

9) B

10) B

11) D

12) A

13) D

14) B

15) A

16) C

17) C

18) A

19) C

20) D

21) A

22) A

23) B

24) C

25) B

26) D

27) C

28) A

29) B

30) C

31) B

32) D

33) A

34) C

35) D

36) B

37) A

38) B

39) D

40) C

-------------------------------------------------------------------------------------------------------------

Blue print of the model question paper
Std: XII
Sub: Biology
1st Semester- 2022-23

Unit Content Marks Objectives Total
Area
Knowledge Understanding Application
30% 40% 30%
VSA VSA VSA

Reproduction Sexual 06 1(1) 3(1) 2(1) 06
Reproduction
in flowering
plants
Genetics and Principles of 07 1(1) 3(1) 3(1) 07
evolution inheritance
and variations
Evolution O5 3(1) 2(1) - 05

Biotechnology Biotechnolog 06 - 3(1) 3(1) 06
y: Principles
and processes
Applications 04 1(1) 2(1) 1(1) 04
of
biotechnology
Biology in Human health 07 5(1 1(1) 1(1) 07
human welfare and diseases
Ecology Organisms 05 1(1) 2(1) 2(1) 05
and
population
Total 40 12 16 12 40

Goa board of secondary and higher secondary Education

Alto- Betim Goa

Second Semester Model paper 2022- 2023

Subject : Biology Std : XII
Time : 90 min Max marks: 30

Instructions :

(i) All questions are compulsory.
(ii) Draw diagrams in lead pencil only.
(iii) Question paper consists of three (3) sections A, B, C.
Section A has 09 questions of 01 mark each,
Section B has 06 questions of 02 marks each.
Section C has 03 questions of 03 marks each.
(iv) Total number of questions is 18.
(v) There is no overall choice, however internal choice is
provided in one question of section B and one question of section C.

Section A [ I mark questions]

1) What is humification?
2) Name the membrane that surrounds the Oocyte just before ovulation.
3) If the anticodon on t-RNA is UAC. Which amino acid will bind to the 3` end
of that t-RNA.
4) Comment on succession in dry area.
5) Mr. Shambu was using chemical fertilisers for paddy cultivation. He wants
to try organic farming. Recommend him some biofertilisers suitable for
paddy cultivation.
6) African Black Panther population is decreasing at an alarming rate. Suggest
a suitable method to preserve the gametes of these animals,so as to
prevent them from becoming extinct.
7) Cattle dung is an essential component of a Gober gas plant. Give reason.
8) Species of the plant Lantana is considered threat to ecosystem why?
9) Estimate the time required in seconds for polymerization of 6000bp DNA in
E.coli.

Section B [2 marks questions]

10) Describe the structure of Human sperm.
11) Explain the early symptoms and complications of sexually transmitted
diseases.
12) The sequence of single strand of DNA in a bacterial cell is
3` TACGTACGTACGATT 5`

(i) Construct m-RNA from the given strand.
(ii) How many amino acids will be present in the protein
after translation?
13) How Monascus and Trichoderma can be used for human welfare?
OR
13) How do aerobic and anaerobic microbes play important role in secondary
sewage treatment?
14)The Amazon Forest has about 80, 000 species of plants , where as the Artic
Tundra has only 1700 species . What are the probable reasons for the
difference in number of species?
15) Succession on cooled lava is different from succession on burnt forest land.
Explain.
Section C [ 3 marks questions]

16) Draw a neat diagram showing sectional view of female reproductive system
in Humans.
17) Discuss the various methods of assisted reproductive technologies (ART).
OR
17)Discuss various Natural methods of contraception.
18) State the salient features of Genetic code.

ANSWER KEY- SECOND SEMESTER BIOLOGY MODEL PAPER

Section A [ 1 mark questions]

1) Humification is the accumulation of a dark coloured amorphous
substance called humus that is highly resistant to microbial action and
undergoes decomposition at an extremely slow rate. (1mk)

2) Zona pellucida surrounds the ovum just before ovulation. (1mk)

3) amino acid that will bind to the 3` end of t-RNA is methionine. (1mk)

4) xerarch succession takes place in dry areas and the series progress
from xeric to mesic conditions. (1mk)

5) Cyanobacteria are recommended as bio fertilizers for paddy fields. (1mk)

6) Gametes of threatened species can be preserved in viable condition for
long periods using cryopreservation technique. (1mk)

7) Cattle dung contains anaerobic bacteria called methanogens that
produce methane in a Gobar gas plant. (1mk)

8) Lantana is an invasive weed that can grow and cause harm to native or
indigenous species. (1mk)

9) The rate of polymerisation of DNA in E.coli is 2000bp per second, hence
for polymerisation of 6000bp 3 seconds time duration will be required.
(1mk)

Section B (2 marks questions)
10)
 sperm is a microscopic structure composed of a head, neck, a middle
piece and a tail. (1/2 mk)
 A plasma membrane envelops the whole body of sperm. The sperm head
contains an elongated haploid nucleus, the anterior portion of which is
covered by a cap-like structure, acrosome. The acrosome is filled with
enzymes that help fertilisation of the ovum. (1mk)
 The middle piece possesses numerous mitochondria, which produce
energy for the movement of tail that facilitate sperm motility essential for
fertilisation. (1/2mk)

11)
 Early symptoms of most of these are minor and include itching, fluid
discharge, slight pain, swellings, etc., in the genital region. Infected
females may often be asymptomatic and hence, may remain undetected
for long. (1mk)
 This could lead to complications later, which include pelvic inflammatory
diseases (PID), abortions, still births, ectopic pregnancies, infertility or
even cancer of the reproductive tract.(1mk)

12) i) The m-RNA is
5`AUGCAUGCAUGCUAA 3` (1mk)
ii) UAA is stop codon hence the amino acids in protein are 4. (1mk)

13)
 Trichoderma polysporum is used to produce cyclosporin A which is a
immunosuppressive agent used in organ transplant.(1mk)

 Monascus purpureus is used to produce statins which is a blood
cholesterol lowering agent which acts by competitively inhibiting enzyme
responsible for synthesis of cholesterol.(1mk)

OR
13)

 Aerobic microbes : Primary effluent is passed through large aeration
tanks where it is Constantly agitated and air is passed through it.
This vigorous growth of aerobic microbes form flocs [ mass of bacteria
and fungi] this processes significantly reduces the BOD. (1mk)
 Anaerobic microbes : The bacterial flock sediment called activated
sludge is pumped in anaerobic sludge digester. Here anaerobic bacteria
and fungi produce mixture of gases methane ,hydrogen sulphide and
carbon dioxide. (1mk)

14)

 Speciation is generally a function of time, unlike temperate regions
subjected to frequent glaciations in the past, tropical latitudes have
remained relatively undisturbed for millions of years and thus, has long
evolutionary time for species diversification
(1mk)
 -Tropical environments, unlike temperate ones, are less seasonal,
relatively more constant and predictable. Such constant environments

promote niche specialisation and lead to a greater species diversity
(1mk)
 -There is more solar energy available in the tropics, which contributes to
higher productivity; this might contribute indirectly to greater diversity.
(1mk)

(Any two points)

15)
 Succession on cooled lava is called primary succession where no life
existed earlier whereas succession on burnt area is a secondary
succession where life existed earlier but is destroyed.(1 mark)
 On cooled lava, development of biotic communities is slow as soil
sediment is absent whereas in a burnt forest it is fast as soil sediment is
already present.(1 mark)
Section C ( 3 marks questions)

16)

( Labelling not expected)

17)

 In vitro fertilisation (IVF–fertilisation outside the body in almost similar
conditions as that in the body) followed by embryo transfer (ET) is one of
such methods. In this method, popularly known as test tube baby
programme, ova from the wife/donor (female) and sperms from the
husband/donor (male) are collected and are induced to form zygote under
simulated conditions in the laboratory. The zygote or early embryos (with up
to 8 blastomeres) could then be transferred into the fallopian tube (ZIFT–
zygote intra fallopian transfer) and embryos with more than 8 blastomeres,
into the uterus (IUT – intra uterine transfer), to complete its further
development Embryos formed by in-vivo fertilisation (fusion of gametes

within the female) also could be used for such transfer to assist those
females who cannot conceive. (1mk)

 Transfer of an ovum collected from a donor into the fallopian tube (GIFT –
gamete intra fallopian transfer) of another female who cannot produce one,
but can provide suitable environment for fertilisation . (1mk)

 Intra cytoplasmic sperm injection (ICSI) is another specialised procedure to
form an embryo in the laboratory where sperm is injected in the ovum.
(1mk)

 Infertility cases either due to inability of the male partner to inseminate the
female or due to low sperm counts in the ejaculates, could be corrected by
artificial insemination (AI) technique. In this technique the semen collected
either from the husband or a healthy donor is artificially introduced either
into the vagina or into the uterus (IUI – intra-uterine insemination) of the
female. (1mk)
[ Any three methods]

OR
17)
 Natural methods work on the principle of avoiding chances of ovum and
sperms meeting. Periodic abstinence is one such method in which the
couples avoid or abstain from coitus from day 10 to 17 of the menstrual
cycle when ovulation could be expected. As chances of fertilisation are very
high during this period, it is called the fertile period. Therefore, by
abstaining from coitus during this period, conception could be prevented.
(1mk)

 Withdrawal or coitus interruptus is another method in which the male
partner withdraws his penis from the vagina just before ejaculation so as to
avoid insemination. (1mk)

 Lactational amenorrhea (absence of menstruation) method is based on the
fact that ovulation and therefore the cycle do not occur during the period of
intense lactation following parturition. Therefore, as long as the mother
breast-feeds the child fully, chances of conception are almost nil. (1mk)

18)The salient features of genetic code are as follows:

 The codon is triplet. 61 codons code for amino acids and 3 codons do not
code for any amino acids, hence they function as stop codons.
 Some amino acids are coded by more than one codon, hence the code is
degenerate.
 The codon is read in mRNA in a contiguous fashion. There are no
punctuations.
 The code is nearly universal: for example, from bacteria to human UUU
would code for Phenylalanine (phe). Some exceptions to this rule have
been found in mitochondrial codons, and in some protozoans.
 AUG has dual functions. It codes for Methionine (met) , and it also act as

initiator codon.
 UAA, UAG, UGA are stop terminator codons.

( six points ½ mk each)

BLUE PRINT OF BIOLOGY MODEL PAPER (STD XII)

SECOND SEMESTER-2022-23

Sr.NO UNIT & CHAPTER Knowledge Understanding Application Skill Total
VSA SA2 SA1 VSA SA2 SA1 VSA SA2 SA1 VSA SA2 SA1
1mk 2mk 3mk 1mk 2mk 3mk 1mk 2mk 3mk 1mk 2mk 3mk
I REPRODUCTION
1. Human 1(2) 1(1) 1(3) 6
Reproduction
2. Reproductive Health 1(3)* 1(2) 5

II GENETICS AND
EVOLUTION
3. Molecular Basis of 1(3) 1(1) 1(1) 1(2) 7
Inheritance

III BIOLOGY IN
HUMAN WELFARE
4. Microbes in Human 1(1) 1(2)* 1(1) 4
Welfare

IV ECOLOGY
5. Ecosystem 1(1) 1(1) 1(2) 4
6. Biodiversity and 1(1) 1(1) 1(2) 4
Conservation
Total 9 11 7 3 30
Weightage 30% 35% 25% 10%