Bhagya

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf Model 2022 to improve time management during exams.

Kerala Plus Two Zoology Board Model Paper 2022 with Answers

Part – I

A. Answer any three questions from 1 to 4. Each carries 1 score.

Question 1.
Mention any one of the factors that affects Hardy Weinberg equilibrium.
Answer:
Gene migration

Question 2.
Embryo with 8-16 Blastomeres is called
Answer:
Morula

Question 3.
Expand SNPs
Answer:
Single nucleotide polymorphism

Question 4.
State the term indicating the ceasing of menstrual cycle.
Answer:
Menopause

B. Answer all questions from 5 to 6. Each carries 1 score. (2 × 1 = 2)

Question 5.
The World Summit on Systainable Development was held in 2002 in _______ South Africa.
Answer:
Johannesburg

Question 6.
The first antibiotic discovered was
Answer:
Penicillin

Part-II

A. Answer any two questions from 7 to 9. Each carries 2 scores. (2 × 2 = 4)

Question 7.
Write any four characteristic features of individual inflicted with Down’s syndrome.
Answer:

1. Short statured
2. Small round head,
3. Furrowed tongue,
4. Partially open mouth

Question 8.
Fungi forms symbiotic associations with plants. What advantages the plant derives from this association?
Answer:

1. This associations helps to absorbs phosphorus from soil:
2. Resistance to root-borne pathogens,
3. Tolerance to salinity and drought,
4. Overall increase in plant growth and development

Question 9.
Complete the table with appropriate terms.

Name of Disease	Causative Organism	Type of Pathogen
Typhoid	A	Bacteria
B	Plasmodium	Protozoa
Ringworm	Microsporum	C
Ascariasis	D	Helminth

Answer:
A – Salmonella typhi
B – Malaria
C – Fungi
D – Ascaris

Answer any two questions from 10 to 13. Each carries 2 scores. (2 × 2 = 4)

Question 10.
Differentiate active immunity and passive immunity.
Answer:

Active Immunity	Passive Immunity
When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body Active immunity is slow and takes time to give its full effective response.	When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity Passive immunity is quick and takes short time to give its full effective response.

Question 11.
(a) Name the theory of origin of life proposed by Oparin and Haldane.
(b) Who experimentally proved theory?
Answer:
a) Chemical evolution
b) S.L. Miller

Question 12.
Complete the pathway of milk secreted from the alveoli of mammary glands.

Answer:
a) Mammarytubule
b) Mammary duct

Question 13.
Describe test cross and mention its significance.
Answer:
a) Itis the crossing of a Fi progenywith its recessive parent.
b) It is used to find unknown genotype of an individual

Part – III

A. Answer any three questions from 14 to 17. Each carries 3 scors. (3 × 3 = 9)

Question 14.
‘Prevention is better than cure’. What are the measures useful for prevention and control of alcohol and drugs abuse among adolescents? (any three measures)
Answer:

1. Avoid undue peer pressure
2. Education and counselling
3. Seeking help from parents and peers.

Question 15.
Pedigree study provides a strong tool in human ‘ genetics to trace the inheritance of a specific trait.
Define Pedigree analysis and identify the following symbols used in Pedigree analysis:

Answer:
Pedigree analysis Analysis of trait in a several generations of a family is called pedigree analysis.

1. Mating between relatives (consanguineous mating)
2. Sex unspecified
3. Female
4. Mating

Question 16.
The graph showing species area relationship is given.

(b) How is species richness related to area?
(c) What is the range of ‘Z’ value?
Answer:
a)  Z = slope of the line (regression coefficient)
C = Y – intercept

b) Within a region species richness increased with increasing explored area, but only up to a limit

c) 0.1 to 0.2

Question 17.
Distinguish homologous organs and analogous organs with one example for each and mention the type of evolution that led to the formation of homologous and analogous organs.
Answer:

Homologous organs	Analogous organs
Homologus organs are organs having same structure and origin but different functions.	Analogous Organs having same function but different structure and origin
Eg: whales, bats,Cheetah and human share similarities in the pattern of bones of forelimbs	Eg: Wings of butterfly and of birds
Homologus organs are developed due to divergent evolution.	Analogous are deve-loped due to Con-vergent evolution

B. Answer the following questions. Carries 3 scores. (1 × 3 = 3)

Question 18.
In Eukaryotes the heterogenous nuclear RNA (hnRNA) is a precursor of mRNA’. Explain the steps involved in the processing of hnRNA.
Answer:
The Heterogenous nuclear RNA (HnRNA) contain both the exons and the introns and are non-functional.
Hence, it is subjected to a processing.

Splicing : Here the introns are removed and exons are joined

Capping : In capping an unusual nucleotide (rnethyi guanosine triphosphate) is added to the 5’-end of
hnRNA..

Tailing : In tailing, adenylate residues (200-300) are added at 3’-end of a template strand

Part – IV

Answer any one question from 19 to 20. Carries 5 scores. (1 × 5 = 5)

Question 19.
(a) What is the central dogma in molecular biology and name any two processes involved in it?
(b) “In Eukaryotes, gene expression can be regulated at several levels.” Which are they?
Answer:
(a) Central Dogma in molecular biology is the unidirectional flow of information from DNA-RNA- Protein Processes in central Dogma in molecular biology

1. DNA Transcription
2. DNA Translation

(b) Regulation of gene expression in Eukaryotes

1. Transcriptional level (formation of primary transcript),
2. Translational level

Question 20.
Diagrammatic sectional view of the female reproducitve system is given below.
(a) Identify the parts labelled as A, B, C and D.
(b) Mention the surgical contraceptive methods in male and female and name the part which is cut or tied up in each method.

(a) Identify the parts labelled as A, B, C and D.
(b) Mention the surgical contraceptive methods in male and female and name the part which is cut or tied up in each method.
Answer:
(a) A – Ampulla
B – Ovary
C – Fimbriae
D – Cervical canal

b) Surgical contraceptive method in male : Vasectomy
The part which is cut or tied up in Vasectomy : Vas deferens
Surgical contraceptive method in male : Tubectomy.
The pat which is cut or tied up in Tubectomy : fallopian tube.

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf Model 2023 to improve time management during exams.

Kerala Plus Two Zoology Board Model Paper 2023 with Answers

I. Answer any 3 q uestions from 1 -5. Each carries 1 score. (3 × 1 = 3)

Question 1.
Write the part of fallopian tube where fertilization takes place in human beings.
Answer:
Aampullary-isthmic junction

Question 2.
Select the completely curable sexually transmitted infections (STIs) from the following:

Genital herpes SPphilis Chiamydiosis Hepatities-B

Answer:
Syphilis, Chlamydiasis

Question 3.
obserye the given figure showing global magnitude of biodiversity in vertebrates. Identify the group of animals labelled as A.

Answer:
Fishes

Question 4.
Expand:
(a)UTR
(b)VNTR
Answer:
(a) Untranslated Regions
(b) Variable Number of Tandem Repeats

Question 5.
Identify the first word pair relationship and fill theblank with suitable word for second pair.
Answer:
Brain

II. Answer any 9 questions from 6-16. Each carries 2 scores.

Question 6.
(a) Define placenta.
(b) Write any 2 hormones secreted from placenta.
Answer:
(a) Structural and functional connection between embryo and maternal body is called placenta I Chorionic villi and uterine tissues together form the placenta.

(b)
1. Human chorionic gonadotropin
2. Human placental lactogen

Question 7.
Biodiversity loss is dangerous threat facing planet earth in present days. Write the four reasons of Biodiversity loss given as evil quartet.
Answer:

1. Habitat loss and fragmentation
2. Over-exploitation
3. Alien species invasions
4. Co-extinctions

Question 8.
(a) Define homologous organs.
(b) Analogous structures are a result of the evolution.
Answer:
(a) Organs that has similar structure but having different function.
(b) Convergent evolution.

Question 9.
Name the microbes which produce the following bioactive molecules and write use of (a) and (b).
(a) Cyclosporin A
(b) Statin
Answer:
(a) Trchodenna polysporum.
Used as Immunosuppressive agent.

(b) Monescus purpureus,
Blood diolesterol lowering agents.

Question 10.
Complete the table by filling (A) and (B)

Birth Control Methods
Sterilisation	(B) ________
Vasectomy (A) _______	Multiload 375 Lipper’s Loop

Answer:
(A) – Tuboctomy
(B) – Non-medicated IUDs

Question 11.
Identify the given symbols of Pedegree.

Answer:
(a) MaleorUnaffected male
(b) Female or Unaffected female
(C) Mating
(d) Mating between relatives or consanguineous mating.

Question 12.
Observe the given figure and answer the following questions:

(a) Identify the given strucutre
(b) Name (A) and (B)
Answer:
(a) Nudeosorne
(b) (A)-DNA
(B) Histone octamer

Question 13.
Complete the given representation:

Answer:
(A) Skin
(B) Physiological Barrier
(C) PMNL – neutrophils or Monocytes
(D) Cytokine Barriers.

Question 14.
(a) A man with blood group ‘AB marries a woman with blood group ‘O’. Write the possible genotes of blood grotipsAB and O.
(b) Write the possible genotypes of their offsprings by suing Punnet Square.
Answer:
(a) AB blood group genotpe – \(\|\left.^A\right|^B\)
O blood group genotype – ii

Question 15.

Scientists	Contribution
George Gamow	DNA finger-printing
Alec Jeifreys	Chargaff Rule
Frederick Griffith	Genetic Code
Taylor and Colleagues	Transformation experiment
	DNA replication

Answer:

Scientists	Contribution
George Gamow	Genetic Code
Alec Jeifreys	DNA finger-printing
Frederick Griffith	Transformation experiment
Taylor and Colleagues	DNA replication

Question 16.
Using the given terms in brackets complete the evolutionary stages of man. (homo habilis, Ramapithecus, Homo erectus, Neanderthal man)

Answer:
(A) Ramapithecus
(B) Homo erectus
(C) Neanderthal man
(D) Homo sapiens (Not given in question)

III. Answer any 3 questions from 17 to 20. Each carries 3 scoers. (3 × 3 = 9)

Question 17.
Observe the given figures A and B. Answer the following questions:

(a) Name the embryoñic stages in figure A and B.
(b) In figure B outertayer is trophoblast, and inner group of cells attached to trophoblast is ___
(C) Define implantation.
Answer:
(a) A – Morula
B – Blastocyst
(b) Inner cell mass
(c) Blastocyst embedded in the endometrium of the uterus is called implantation.

Question 18.
Answer the following questions:
(a) Complete the given representation.

(b) Categorie the following bases into Purines and Pyrimidines:
Adenine, Cytosine, Uracil, Guanine
(c) DNA is made up of two polynucleotide chains where back bone is constituted by ______ and bases project inside.
Answer:
(a) (A) – Transcription
(B) Translation
(b) Purines – Adenine and Guanine. Pyrimidines – Uraail & Cytosine.
(c) Sugar – phosphate.

Question 19.
(a) Cancer causing agents are called ____
(b) Differentiate between benign tumour and malignant tumour.
(c) Write any two methods to detect cancer of the internal organs.
Answer:
(a) Carcinogens.

(b) Benign Tumors:
The cancer, which are localized to a particular tissue, are called benign tumor. They cause little damage.

Malignant Tumors:
Mali gnant tumors consist of mass of proliferative cells. The cells can invade to other tissues

(c) (i) Radiography
(ii) MRI (magnetic resonance imaging).

Question 20.
Observe the figures given in (A), (B) and (C) and answer the questions.
(a) Identify and write the genetic disorder in (A), (B) and (C).
(b) Write any three Mendalian disorders.

Answer:
(a) (A) Down’s Syndrome
(B) Klinefelter’s Syndrome
(C) Turner’s Syndrome
(b) Haemophilia, Sickle-cell anaemia, Phenylketonuna,

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf SAY 2019 to improve time management during exams.

Kerala Plus Two Zoology Question Paper SAY 2019 with Answers

Answer all questions from 1 to 3. Each carries 1 Score. (3 × 1 = 3)

Question 1.
Find out the correct sequence:
a) Fertilisation – Zygote – Blastula – Morula – Cleavage – Implantation
b) Fertilisation – Zygote – Cleavage – Morula – Implantation – Blastula
c) Fertilisation – Zygote – Morula – Cleavage – Implantation – Blastula
d) Fertilisation – Zygote – Cleavage – Morula – Blastula – Implantation
Answer:
Fertilisation-Zygote – cleavage-Morula-blastula Implantation

Question 2.
Identify the following symbols in pedigree Analysis :

Answer:
a) Mating
b) Marriage between relatives

Question 3.
In a double strandard DNA, the ratios between Adenine and Thymine, Guanine and Cytosine are constant and equal one. Who observed this fact?
Answer:
Ervin Chargaff

Answer any 9 questions from 4-14. Each carries 2 Scores.

Question 4.
Observe the cross of a pure violet and white flower.

a) By using the F₁ progeny design a test cross.
b) Mention the significance of test cross.
Answer:

b) It helps to find out the unknown genotype of organism

Question 5.
‘Don’t die of ignorance.
a) About which it is mentioned?
b) List two measures taken by WHO to prevent it.
Answer:
a) HIV infection

b) 1. blood transfusion must be safe
2. use dispossible syringes and needles in public and private Hospitals

Question 6.
Match the following:

A	B
a) Citric Acid	i) Acetobactor aceti
b) Acetic Acid	ii) Clostridium butylicum
c) Lactic acid	iii) Aspergillus niger
d) Butyric Acid	iv) Lacto bacillus
	v) Trycoderma polysporum
	vi) Saccharomyces cervisiae

Answer:

A	B
a) Citric Acid	Aspergillus niger
b) Acetic Acid	Acetobacter aceti
c) Lactic acid	Lactobacil lus
d) Butyric Acid	Clostridium butylicum

Question 7.
Each symptom of two chromosomal disorders are given below:
Gynaecomastia Rudimentary ovary and lack of secondary sexual characters.
Answer:
Gynaecomastia- Kilnefelter’s syndrome Rudimentary ovary and lack of secondary sexual characters – Turner’s Syndrome

Question 8.
Observe the diagram of a double stranded DNAstrand:

Identify the bonds A, B, C & D A, B, C, D
Answer:
A – Hydrogen bond
B – phospho esterbond
C – phospho di esterbond
D – Glycosidic bond

Question 9.
‘LH Surge’ induces the rupture of Graafian follicle.
a) Which gland produces LH and in which day LH Surge happens?
b) Write the role of LH in males.
Answer:
a) Pituitary gland, 14th day

b) LH acts at the Leydig cells and stimulates synthesis and secretion of androgens

Question 10.
Bio-fertilisers are organisms that enrich the nutrient quality of the soil. How these biofertilisers enrich the soil nutrients? Give two examples.
Answer:
a) Microbes can fix atmospheric N₂
Eg. Azospirillum and Azotobacter

Question 11.
Based on evolution in the geological period arrange the plants and animals in the correct order in various million years ago. Choose the appropriate organisms from the bracket.
a) 500 m ya :
b) 350 m ya :
c) 320 m ya :
d) 200 m‘ya :
Answer:
a) 500 mya – Invertebrates
b) 35Omya – jawless fish
c) 320m ya – sea weeds
d) 200mya – Reptiles

Question 12.
The following diagram shows a process in the Ribosome:

Identify the process and explain.
Answer:
Translation step of protein synthesis During this process, ribosome moves from codon to codon along the mRNA and the amino acids are joined by peptide bond i.e polymerisation of amino acids to form a polypeptide.

Question 13.
Make a flow chart using the following terms :
[Natural selection, Struggle for existence, Variation, Origin of species, Over production, Survival of the fittest]
Answer:

Question 14.
Observe the figure and answer the following questions:

a) Identify the given molecule.
b) Mention two types of immune respones in human body.
Answer:
a) Antibody or Immunoglobulin
b) Humoral immune response Cell mediated immunity

Answer any 3 Questions from 15 to 18. Each carries 3 scores. (3 × 3 = 9)

Question 15.
Write the effect of the following drugs in human body:
a) Ophiods
b) Cannabinoids
c) Coca alkaloids
Answer:
a) Ophioids – Effect on central nervous system
b) Can nabinoids – Effect on brain or cardiovascular system of body
c) coca alkaloids – It has a stimulating action on central nervous system, producing a sense of euphoria and increased energy

Question 16.
There are several method of in vitro fertilisation to assist couples who lack the ability of fertilisation.
a) Give the popular name of the programme.
b) Suggest two techniques of in vitro fertilisation and their conditions of transfer to assist these people.
Answer:
a) Assisted reproductive technologies

b) ZIFT : zygote intra fallopian transfer: The zygote or early embryos upto 8 blastomeres transferred into the fallopian tube

GIFT : gamete intra fallopian transfer: Transfer of an ovum collected from a donor into the fallopian tube of another female who cannot produce one, but provide suitable environment for fertilisation and further development

Question 17.
In your school the Science Club decided to conduct a seminar about “Biodiversity conservation – Approaches.” You are invited to present a paper on this seminar. List out the main points you include d in the presentation. [Hint: In Situ, Ex-Situ conservation]
Answer:
In situ conservation – Organisms are protected in their natural habitat Eg. sacred groves, biosphere reserves, national parks and sanctuaries. Ex situ conservation – It is the conservation of threatened animals and plants outside their natural habitat. Examples are Zoological parks, botanical gardens and wildlife safari parks.

Question 18.
Transcription of eukaryotes are more complicated than that of prokaryotes. Explain any two additional complexities found in the transcription of eukaryotes.
Answer:
Three types of RNA polymerases in eukaryotes RNA processing Three important steps are involved – Splicing, capping, Tailing

1. In splicing the introns are removed and exons are joined toether.
2. In capping an methyl guanosine triphosphate is added to the 5’-end of hnRNA.
3. In tailing, adenylate residues are added at 3-end in a template.

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf March 2020 to improve time management during exams.

Kerala Plus Two Zoology Question Paper March 2020 with Answers

I. Answer any 3 questions from 1 – 5. Each carries 1 score. (3 × 1 = 3)

Question 1.
From the following, find out the symbol used in the human pedigree analysis representing male.

Answer:

Question 2.
Name the technique of transferring embryos upto 8 blastomeres into the fallopian tube.
a) GIFT
b) ZIFT
c) ICSI
d) IUI
Answer:
b) ZIFT

Question 3.
Microbe which help in the production of Biogas.
a) Aspergillus nicier
b) Trichoderma Polvsoorum
c) Saccharomyces derevisiae
d) Methanobacterium
Answer:
d) Methanobacterium

Question 4.
Which of the following human ancestor is more ‘ape’ like?
a) Homo habilis
b) Drypithecus
c) Australo pithecines
d) Homo erect us
Answer:
b) Drypithecus

Question 5.
Select the cause of etinction of Cichlid fish in lake Victoria of East Africa.
a) Habitat loss and fragmentation
b) Over-exploitation
c) Alien species invasions
d) Co-extinctions
Answer:
c) Alien species invasions

II. Answer any 9 questions from 6-16. Each carries 2 scores. (9 × 2 = 18)

Question 6.
Some examples of microbes in human welfare are given. Classify them under the heading given below.

Microbes in house hold products	Microbes as biofertil izers

Answer:

Microbes in house hold products	Microbes as biofertil izers
. Pmponibactonum sharmani	. Rhizobium
. Lactic acid bacteria	. Azospinllum
. Sacharomyces cervisiae	. Anabaena
	. Azotobacter
	. Aspergillus niger

Question 7.
Observe the figure given below showing Mendel’s experiment using pea plants.

a) Identify the’crossg!
b) Which are the laws proposed by Mendel based on this observations?
Answer:
a) Monohybrid cross

b) 1. Law of dominance
2. Law of segregaton or Law of purity of gametes

Question 8.
“All copulations lead to fertilization and pregnancy”. Do you agree with this statement? Justify your answer.
Answer:
No.
Fertlisaton can only occur if the ovum and sperms are transported simultaneously to the ampullary isthmic junction.

Question 9.
Fill the blanks in Column A and B using appropriate terms.

Theory	Scientists
a) Theory of natural selection	A
b) Use and disuse of organs	B
c) Theory of mutation	C
d) Theory of spontaneous generation	D

Answer:

Theory	Scientists
a) Theory of natural selection	Charles Darwin
b) Use and disuse of organs	Jean Baptste de
c) Theory of mutation	La marck
d) Theory of spontaneous generation	Hugo deVries

Question 10.
One of the salient features of genetic code is “Universal”.
a) Write any other two salient features of Genetic code.
b) Which is the initiator codon? And name the amino acid it codes.
Answer:
a) 1. The codon is triplet
2. One codon codes for only one amino acid, hence, it is unambiguous and specific

b) AUG-Methionine

Question 11.
Amniocentesis for sex determination is legally banned now.
a) What is amniocentesis?
b) Why it is banned?
Answer:
a) It is the prenatal 1oetal sex determination test based on the chromosomal pattern in the amniotic fluid surrounding the developing embryo

b) It is banned for preventing female foeticides

Question 12.
Name any two protozoan diseases, its causative organism and any two symptoms.
Answer:
Malaria and Amoebiasis
Malaria : Pathogen : Plasmoidum vivax, P. malaria and P. falciparum Symptom: Chill and high fever recurring every three to four days

Amoebiasis: Pathogen: Entamoeba histolytica Symptom: constipation, abdominal pain and cramps

Question 13.
Tropical Amazonian rainforest in South America has the greatest biodiversity on earth. Do you agree with this? Explain.
Answer:
Yes

1. Temperate regions subjected to frequent glaciations in the past but the tropics undisturbed for millions of years, so in tropics evolution leads to species diversification.
2. Tropical environments are less seasonal, constant and predictable. Such constant envronments promote niche specialis.ation and lead to a greater species diversity
3. The availability more solar energy In the tropics causes higher productivity, so it leads to greater diversity.

Question 14.
Complete the illustration chart given below.

Answer:
a) Oploids
b) Central nervous system
C) Papayer somniferum
d) Cannabis sativa

Question 15.
Correct the following statements, if there is any mistake:
a) Haemophilia is an autosome linked recessive disease.
b) Turner’s syndrome is due to the presence of an additional copy of X chromosome.
Answer:
a) Haemophilia is a sex linked recessive disease
b) Turner’s sidrome is due to the absence one of the X chromosome

Question 16.
p² + 2pq + q² = 1 denotes an evolutionary principle.
p² + 2pq + q² = 1 agianto)”
a) Name the principle.
b) Mention any three factors affecting this.
Answer:
a) Hardy—Weinberg prindple

b) i) Gene migratiop
ii) Genetic drift
iii) Mutation

III. Answer any 3 questions from 17 – 20. Each carries 3 scores. (3 × 3 = 9)

Question 17.
Observe the figure given below:

a) Identify the process in the picture.
b) Name any two enzymes needed for this process,
c) Write the peculiarities of the newly synthesized daughter strands.
Answer:
b) Helicase and DNA ligase
c) Among the two newly synthesized strands,One strand is continuously produced and other strand is discontinuously produced.

Question 18.
Explain the measures useful for prevention and control of alcohol and drugs abuse among adolescents.
Answer:

1. Avoid undue peer pressure
2. Education and counseling
3. Seking help from parents and peers

Question 19.
The graph given below shows the level of the ovarian hormones in a normally menstruating woman during the follicular phase.

a) Name ‘A’ and ‘Bi.
b) Reconstruct the graph showing the level of hormones in luteal phase.
c) Name the hormone secreted by Corpus Luteum and mention its function.
Answer:
A – Progesterone

B – Estrogen

(c) Progesterone Function:
It support during pregnancy or it maintain Endometrium of uterus

Question 20.
A DNA sequences is provided below.
a) Write down the sequence of its complementary strand.
b) Name the enzyme involved in transcription of DNA.
c) What would happen if both the strands of the DNA act as templates for transcription?
Answer:
a) 3’-TACG TACG TACG TACG TACG TACG TA-5’

b) DNA dependent RNA polymerase

c) If both strand act as a template the following things will happen

1. Two RNA molecule will be produced with different sequences and results in the formation of 2 different protein.
2. Two RNA molecu’e will be produced, they are complementary to each other, hence ds RNA will not translate into protein.

Reviewing Kerala Syllabus Plus Two Physics Previous Year Question Papers and Answers Pdf March 2024 helps in understanding answer patterns.

Kerala Plus Two Physics Previous Year Question Paper March 2024

Time: 2 Hours
Total Scores : 60

I. Answer any 5 questions from 1 to 7. Each carries 1 score. (5 × 1 = 5)

Question 1.
The SI unit of electric flux
(a) NC^-1
(b) NmC
(c) Nm²C²
(d) Nm²C
Answer:
(c) Nm²C²

Question 2.
The net electric field inside a conductor when placed in an external electric field is
(a) Zero
(b) Half
(c) Two times
(d) Four times
Answer:
(a) Zero

Question 3.
The SI unit of power of lens
(a) N
(b) J
(c) W
(d) D
Answer:
(d) D

Question 4.
‘The locus of points which have the same phase is called a wave front” the statement is True/Faise.
Answer:
True.

Question 5.
The expression for de Broglie wavelength associated with a particle is ………….. .
Answer:
\(\frac{h}{mV}\) = \(\frac{h}{P}\)

Question 6.
Which element in the periodic table shows maximum binding energy per nucleon?
Answer:
Fe⁵⁶ (Iron)

Question 7.
What is an intrinsic semiconductor?
Answer:
A semiconductor in its pure form is called in-trinsic semiconductor.

Answer any 5 questions from 8 to 14. Each carries 2 scores. (5 × 2 = 10)

Question 8.
What is an equipotential surface? Give an example.
Answer:
An equipotential surface is a surface in a region of space where every point on that surface has the same electric potential. In other . words, it’s a surface where the electric potential is constant.
Example: All points equidistant from a point charge.

Question 9.
Define drift velocity, give its equation.
Answer:
Drift velocity is defined as the average velocity acquired by and electron under the applied electric field.
V_d = \(\frac{-eEτ}{m}\)

Question 10.
State Gauss’s law in maghetism.
Answer:
The net magnetic flux through ant closed surface is zero.
ϕ_B = \(\sum_{\text {all }} \mathrm{B} \cdot \Delta \mathrm{~S}=0\)

Question 11.
What is magnetic flux and how is it measured?
Answer:
Magnetic flux is defined as the number of magnetic field lines passing through a given area.
The number of magnetic field lines passing through the surface gives the measure of magnetic flux.
ϕ = \(\sum_{\text {all }} \overrightarrow{\mathrm{B}} . \Delta \overrightarrow{\mathrm{S}}\)

Question 12.
The household line voltage of ac measured is 220 V, calculate its peak voltage.
Answer:
V_m = V_rms × \(\sqrt{2}\)
= 1.414 × 220
= 311 V

Question 13.
What is stopping potential?
Answer:
This is minimum negative potential given to collector plate for which the photo electric current becomes zero.
Stoping potential is denoted as V₀
\(\frac{1}{2}\) mV² max = eV₀

Question 14.
What is nuclear fission? Give one example.
Answer:
Nuclear fusion is the splitting of a heavy nucleus into two lighter nuclei.
Splitting of the uranium-235 nucleus when it is bombarded with neutrons.

Answer any 6 questions from 15 to 21. Each carries 3 scores. (6 × 3=18)

Question 15.
State and explain the force between electric charges.
Answer:

The force of attraction or repulsion between two point charges is directly proportional to the product of the charge and inversely proportional to the square of the distance between them. The force between the charges is given by,
F ∝ q₁q₂
F ∝ \(\frac{1}{r^2}\)
F ∝ \(\frac{q_1 q_2}{r^2}\)
F = \(K \frac{q_1 q_2}{\mathbf{r}^2}\)
when the medium between the charges is air or vacuum.
\(F_{\text {vecuum }}\) = \(\frac{1}{4 \pi \varepsilon_0} \frac{q_1 q_2}{r^2}\)

Question 16.
Figure shows the two current carrying conductors. Derive the expression for force between the conductors.

Answer:

The magnitude of the magnetic induction B-p at the right side conductor Q is,
\(B_{P}\) = \(\frac{\mu_0 i_1}{2 \pi d}\)
The force on a length L of the ‘Q’ conductor is Fg/> = Bpi2L
\(F_{QP}\) = \({B_P i_2 L}\)
= \(\frac{\mu_0 i_1}{2 \pi d} i_2 L\)
= \(\frac{\mu_0 i_1 i_2}{2 \pi d} L\)
Force per unit length can be written as
\(F_{QP}\) = \(\frac{\mu_0 i_1 i_2}{2 \pi d}\)

Question 17.
Compare dia, para and ferromagnetic substances with suitable examples.
Answer:
Diamagnetic substance:

• These substances when placed in a magnetic field, acquire feeble magnetism opposite to the direction of the magnetic field.
• They are feebly repelled by a magnet.
• The relative permeability of these substances are slightly less than 1 .
• The susceptibility has a small and negative value.
• When they are placed in a magnetic field, the magnetic lines of force are repelled. They do not pass through the material.
• Examples: Copper, Silver, Bismuth.
  

Paramagnetic substance:

• These substances when placed in a magnetic field, acquire feeble magnetism in the direction of the magnetic field.
• They are feebly attracted by a magnet.
• The relative permeability of these substances are slightly greater than 1.
• The susceptibility value is small and positive.
• When they are placed in a magnetic field, the magnetic lines offeree pass through them.
• Examples: Aluminium, Sodium, Calcium, Oxygen (at STP)
  

Ferromagnetic substance :

• These substances when placed in a magnetic field are strongly magnetised in the direction of the magnetic field.
• They are strongly attracted by a magnet.
• The relative permeability of these substances is very high.
• The susceptibility is large and positive.
• When they are placed in a magnetic field, most of the magnetic lines of force pass through them.
• Examples : Iron, Nickel, Cobalt, natural magnet.

Question 18.
What is self-induction and define the expression for self-inductance of a solenoid.
Answer:
When current in a coil changes the magnetic flux linked with the coil also changes and a back emf is induced in the coil. This phenomenon is known as self induction.
The magnetic flux through one turn of the solenoid is given by,
ϕ = BA = (μ₀nI)A
The magnetic flux linkage in the solenoid with a total number of n/turns is given by,
ϕ = μ₀n²AIl
But ϕ = LI
LI = μ₀n²AIl
L = μ₀n²Al

Question 19.
Briefly explain the electromagnetic spectrum.
Answer:
Electromagnetic spectrum is the arrangement of electro magnetic waves in the increasing order of wavelength. Thee.m waves have been arranged in terms of increasing wavelength y-ray, X – ray, Ultraviolet rays,Visible light, Infrared rays, Microwaves, Radio waves.

1. Radio Waves: These have the lowest frequencies and longest wavelengths in the spectrum. They are used for communication, broadcasting, and radar.
2. Microwaves: With slightly higher frequencies and shorter wavelengths than radio waves, microwaves are used in microwave ovens, satellite communication, and certain types of radar.
3. Infrared Radiation: Just beyond the visible spectrum, infrared radiation has frequencies slightly higher and wavelength slightly lower than microwaves.
4. Visible Light: This is the only part of the electromagnetic spectrum that humans can directly perceive with their eyes.
5. Ultraviolet (UV) Radiation: Beyond the visible spectrum, UV radiation has shorter wavelengths and higher frequencies than visible light.
6. X-rays: With even shorter wavelengths and higher frequencies than UV radiation, X-rays are used in medical imaging (X-ray radiography), security scanning, and industrial applications.
7. Gamma Rays: These have the shortest wavelengths and highest frequencies in the spectrum.

Question 20.
Write the postulates of Bohr’s atom model.
Answer:

1. The nucleus of an atom is a small positively charged core where whole of its mass is supposed to be concentrated.
2. The electrons revolve round the nucleus in fixed orbits of definite radii. They do not radiate any energy as long as the electron is in certain orbit.
3. The electrons can revolve only in those orbits, in which its angular momentum is an integral multiple of h/27i. L = mvr = nh/2. where n is known as quantum number of the orbit and h is Planck’s constant.
4. Electron jumps from higher energy orbit to lower energy orbit,by emitting the energy equivalent to the energy gap, in the form of radiations.
   hv = E₂ – E₁

Question 21.
What is a rectifier ? Draw the circuit diagram and input, output wave forms of a full wave rectifier.
Answer:
A rectifier is an electrical device that converts alternating current (AC) into direct current (DC). The process of converting AC to DC is known as rectification. Rectifiers are essential components in various electronic circuits and power supply systems, as many electronic devices required DC power to operate. Rectifiers can be classified into two main types:
Half-Wave Rectifier: This type of rectifier allows only one half of the AC input waveform to pass through to the output, while blocking the other half. It typically consists of a single diode connected in series with the load.

Full-Wave Rectifier: Full-wave rectifiers allow both halves of the AC input waveform to be utilized, resulting in a more continuous DC output.

Answer any 3 questions from 22 to 25. Each carries 4 scores. (3 × 4 = 12)

Question 22.
(a) Complete the diagram with proper marking of direction. (1)

Answer:

(b) Derive the expression for electric field intensity at a point from an infinitely long straight conductor carrying charge. (3)
Answer:

Consider a thin infinitely long straight rod conductor having charge density λ. (λ = \(\frac{q}{I}\))
To find the electric field at P ,we imagine a Gaussian surface passing through P.
Then according to Gauss’s law we can write,
\(\int \overrightarrow{\mathrm{E}} \cdot \mathrm{~d} \overrightarrow{\mathrm{~s}}\) = \(\frac{1}{\varepsilon_0} q\)
\(\int E d s \cos \theta\) = \(\frac{1}{\varepsilon_0} q\) (θ = 0°)
\(E \int d s\) = \(\frac{\lambda I}{\varepsilon_0}\) (Since q = λI)
Integrating over the Gaussian surface, we get (we need not integrate the upper and lower surface because, electric lines do not pass through these surfaces.)
E 2πrI = \(\frac{\lambda I}{\varepsilon_0}\) (L.S.A. of cyhnder = 2πrI)
E = \(\frac{1}{2 \pi r I} \frac{\lambda I}{\varepsilon_0}\)
E = \(\frac{1}{2 \pi \varepsilon_0} \frac{\lambda}{r}\)

Question 23.
(a) State Ohm’s, law. (1)
Answer:
Ohm’s Law states that the current through a conductor between two “points is directly proportional to the potential difference across its ends. Mathematically, we can represent it as V = IR, where V is the potential difference, I is the current, and R is the resistance of the conductor.

(b) Derive Wheatstone’s network principle.
Answer:
Four resistances P,Q,R and S are connected as shown in figure. Voltage ‘V’ is applied in between A and C. Let I₁, I₂,I₃ and I₄ be the four currents passing through P, R,Q and S respectively.

Working
The voltage across R.
When key is closed, current flows in different branches as shown in figure. Under this situation
The voltage across P, V_AB = I₁P
The voltage across Q, V_BC = I₃Q ………(1)
The voltage across R, V_AD = I₂R
The voltage across S, V_DC = I₄S
The value of R is adjusted to get zero deflection in galvanometer. Under this condition,
I₁ = I₃ and I₂ = I₄ ………(2)
Using Kirchoffs second law in loopABDA and BCDB, we get
V_AB = V_AD …………(3)
and V_BC = V_DC ……….. (4)
Substituting the values from eq(1) in to (3) and (4), we get
I₁P = I₂R …………..(5)
and I₃Q = I₄S ………….(6)
Dividing Eq(5)byEq(6)
\(\frac{I_1 P}{I_3 Q}\) = \(\frac{\mathrm{I}_2 \mathrm{R}}{\mathrm{I}_4 \mathrm{~S}}\)
\(\frac{P}{Q}\) = \(\frac{R}{S}\) [since I₁ = I₃ and I₂ = I₄]
This is called Wheatstone condition.

Question 24.
(a) State Snell’s law of refraction. (1)
Answer:
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant.
\(\frac{\sin i}{\sin r}\) = n₂₁
where n₂₁ is a constant, called the refractive index of medium 2 with respect to medium 1.

(b) Explain critical angle and total internal reflection.
Answer:
The angle of incidence for which angle of refraction becomes 90° is called critical angle and total internal reflection is the phenomenon where light travels from denser to rarer medium and the angle of incidence when becomes greater than critical angle, there is no refracted light and all the light is reflected back to the denser medium. This phenomenon is known as total internal reflection.

Question 25.
(a) What are coherent sources? (1)
Answer:
Coherent sources of light are those which have constant their difference between them.

(b) In Young’s double slit experiment, interference pattern is observed at 5 cm from the slits with a fringe width of 1 mm. Calculate the separation between the slits. (k = 500 A) (3)
Answer:
λ = 5000 A
n = 3
D = 1.5 m
wkt,
β = \(\frac{nλD}{d}\)
d = \(\frac{nλD}{ß}\)
= \(\frac{3 \times 5000 \times 10^{-10} \times 1.5}{10^{-2}}\)
= 225 × 10^-6 m
d = 0.0225 cm

Answer any 3 questions from 26 to 29. Each carries 5 scores. (3×5 = 15)

Question 26.
(a) What is the principle of a capacitor? (1)
Answer:
Whenever two neutral conductors are placed nearby, and a potential difference is applied to them, then equal and opposite charges are induced on them.
Therefore, due to these charges, Energy is stored in the form of Electric Field in the gap between them.
A capacitor is device used to store Energy.
The charge appearing on the conductors is directly proportional to the Potential difference applied to them. i.e.
Q ∝ V
⇒ Q = CV
Where C is the constant of proportionality, called capacitance of the system, it depends on physical dimensions of the conductors.

(b) Derive the expression for capacitance of a parallel plate capacitor. (2)
Answer:

Electric field between the plate is given by,
E = \(\frac{\sigma}{\varepsilon_0}\) = \(\frac{Q}{\varepsilon_0 \mathrm{~A}}\) [σ = \(\frac{Q}{A}\)]

Potential difference between the two plates is,
V = Ed = \(\frac{Qd}{\varepsilon_0 A}\)]

Capacitance of capacitor,
C = \(\frac{Q}{V}\) = \(\frac{Q}{\frac{Q d}{\varepsilon_0 A}}\) = \(\frac{{\varepsilon_0 A}}{d}\)

(c) A 12 pF capacitor i connected to 50 V battery. How much electrostatic energy is stored in the capacitor? (2)
Answer:
U = \(\frac{1}{2}\) CV²
= \(\frac{1}{2}\) × 12 × 10^-12 ×50²
= 1.5 × 10^-8 J

Question 27.
(a) The direction of magnetic field around a current carrying conductor is given by . (1)
Answer:
Eight hand thumb rule or right hand grip rule or Maxwell’s Cork screw rule(write name of any one rule).

(b) State Biot-Savart law. (1)
Answer:

The strength of the magnetic field dB is
(i) directly proportional to the current
I, dB ∝ I
(ii) directly proportional to the length
dl, dB ∝ dl
(iii) directly proportional to the sine of the angle (θ) between the element and the line joining the midpoint of the element to the point, dB ∝ sin θ.
(iv) inversely proportional to the square of the distance between the element and the point,
Combining these we get
dB ∝\(\frac{1}{r^2}\)
dB ∝\(\frac{I d l \sin \theta}{r^2}\) = \(\frac{\mu_0}{4 \pi} \frac{I d l \sin \theta}{r^2}\)

(c) Derive the expression for magnetic field on the axis of a circular coil carrying current.(3)
Answer:

Consider a circular loop of radius ‘a’ and carrying current I. Let P be a point on the axis of the coil, at distance x from A and r from ‘O’. Consider a small length dl at A.
The magnetic field at ‘p’ due to this small element dI,
dB = \(\frac{\mu_0 \mathrm{Idl} \sin 90}{4 \pi \mathrm{x}^2}\)
dB = \(\frac{\mu_0 \mathrm{Idl}}{4 \pi \quad \mathrm{x}^2}\) …………..(1)
The dB can be resolved into dB cosϕ (along P_y) and dB sinϕ) (along P_x).
Similarly consider a small element at B, which produces a magnetic field ‘dB’ at P. If we resolve this magnetic field we get.
dB sinϕ (along P_x) and dB cosϕ (along P_y1)
dB cosϕ components cancel each other, because they are in opposite direction. So only dB sinϕ components are found at P, so total field at P is

Question 28.
(a) Write the expression for instantaneous emfofa.c. (1)
Answer:
V = V_m sin t or E = E₀

(b) Identify A, B and C in figure. (1)

Answer:
A – Resistance
B – Inductor
C – Capacitor

(c) Draw the phasor diagram of the above circuit and write the expression for imped-ance in the circuit, then mention the terms. (3)
Answer:

Impendence of the circuit Z is given by
Z = \(\sqrt{\mathrm{R}^2+\left(\mathrm{L} \omega-\frac{1}{\mathrm{C} \omega}\right)^2}\)
R = Resistance, XL = Lω; – inductive reactance, x_c = \(\frac{1}{\mathrm{C} \omega}\) :- Capacitive reactance.

Question 29.
(a) Derive lens maker’s formula. (3)
Answer:
Consider a thin lens of refractive index n₂ formed by the spherical surfaces ABC and ADC. Let the lens is kept in a medium of refractive index n₁. Let an object ‘O’ is placed in the medium of refractive index n₁. Hence the incident ray OM is in the medium of refractive index n1 and the refracted ray MN is in the medium of refractive index n₂.

The spherical surface ABC (radius of curvature R₁) forms the image at I₁. Let ‘u’ be the object distance and V₁ be the image distance. Then we can write,
\(\frac{n_2}{v_1}\) – \(\frac{n_1}{u}\) = \(\frac{n_2-n_1}{R_1}\) ……….(1)
This image I₁ will act as the virtual object for the surface ADC and forms the image at v. Then we can write,
\(\frac{n_1}{v}\) – \(\frac{n_2}{v_1}\) = \(\frac{n_1-n_2}{R_2}\) ……….(2)
Adding eq (1) and eq (2) we get
\(\frac{n_2}{v_1}\) – \(\frac{n_1}{u}\) + \(\frac{n_1}{v}\) – \(\frac{n_2}{v_1}\) = \(\frac{n_2-n_1}{R_1}\) + \(\frac{n_1-n_2}{R_2}\)
\(\frac{n_1}{v}\) – \(\frac{n_1}{u}\) = (n₂ – n₁) (\(\frac{1}{R_1}\) – \(\frac{1}{R2}\))
Dividing throughout by n,, we get
\(\frac{1}{v}\) – \(\frac{1}{u}\) = (\(\frac{n_2}{n_1}\) – 1) (\(\frac{1}{R_1}\) – \(\frac{1}{R2}\))
if the lens is kept in air, \(\frac{n_2}{n_1}\) = n
So the above equation can be written as,
\(\frac{1}{v}\) – \(\frac{1}{u}\) = (n – 1) (\(\frac{1}{R_1}\) – \(\frac{1}{R2}\))
From the definition of the lens, we can take,
when u = ∞, f = v
Substituting these values in the eq (3), we get
\(\frac{1}{f}\) – \(\frac{1}{∞}\) = (n – 1) (\(\frac{1}{R_1}\) – \(\frac{1}{R2}\))
This is lens maker’s formula
\(\frac{1}{f}\) = (n – 1) (\(\frac{1}{R_1}\) – \(\frac{1}{R2}\))

(b) Draw the image formation in a simple microscope. (1)
Answer:

(c) Write the value of least distance of distinct vision. (1)
Answer:
25 cm is the value of least distance of distinct vision.

 

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf March 2021 to improve time management during exams.

Kerala Plus Two Zoology Question Paper March 2021 with Answers

Answer the following questions from 1 to 31 upto a maximum score of 30. (7 × 1 = 7)
I. Each question from 1 to 7 carries 1 score.

Question 1.
Name the oral contraceptive for female developed by CDRI.
Answer:
Saheli

Question 2.
Name the genetic’disorder in which a blood clotting protein is affected leading to non-stop bleeding even through a simple wound.
Answer:
Haemophilia

Question 3.
Under microscope, chromatin is seen as ‘beads-on-string’ like structure. Here, ‘beads’ represent the structures called.
Answer:
Nucleosome

Question 4.
During luteal phase of menstrual cycle, Graafian follicle transforms into
Answer:
Corpus luteum

Question 5.
Organic pollutants in sewage water is measured as
(a) GMO
(b) MPT
(c) BOD
(d) HGP
Answer:
BOD

Question 6.
Select an example for homologous organs.
(a) Eyes of octopus and mammals
(b) Forelimbs of Whales and Bats
(c) Flippers of Penguins and Dolphins
(d) Wings of Birds and Butterflies
Answer:
Forelimbs of Whales and bats

Question 7.
Enzyme used in detergents for removing oily stains from laundry is _____.
(a) Lipase
(b) Protease
(c) Amylase
(d) Pectinase
Answer:
Lipase

II. Each question from 8 to 26 carry 2 scores. (19 × 2 = 38)

Question 8.
‘In a cell, euchromatin and Heterochromatin can be observed under microscope’. Distinguish between euchromatin and Heterochromatin.
Answer:

Euchromatin	Heterochromatin
i) It is loosely packed.	It is densely packed.
ii) It is Trascriptionally active.	It is Transcriptionally Inactive.

Question 9.
Presence of an additional copy of chromosome 21 was observed in a person during diagnosis.
(a) Identify the genetic disorder
(b) Write the characteristic features of this disorder.
Answer:
(a) Down’s Syndrome

(b) 1. Short stature and small round head,
2. Furrowed tongue and partially open mouth

Question 10.
Fill in the blanks to complete the table:

Micro-organism	Use of Micro-organism
i. (a) _____	Curding of Milk
ii. Bacillus thuringiensis	(b) ______
iii. Aspergillus niger	(c) ______
iv. (d) ______	Production of butyric acid

Answer:
(a) Lactic acid bacteria
(b) Control butterfly catterpillars
(c) Citric acid
(d) Clostridium butylicum

Question 11.
If a father is with ‘O’ blood group and mother is with ‘B’ blood group, write the possible blood groups of their children.
Answer:
‘B’ group and ‘O’ roup

Question 12.
Observe the figure

(a) Identify the molecular strucuture given in the figure.
(b) Name the regions labelled as A, B and C.
Answer:
(a) Antibody or Immunoglo’bulins
(b) A – Antigen binding site
B – Light chain
C – Heavy chain

Question 13.
In eukaryotes, gene expression can be regulated at several levels. Write diffèrent levels at which gene expression can be regulated.
Answer:
(i) Transcriptional level
(ii) Translational level

Question 14.
Expand the following terms related with Assisted Reproductive Technologies:
Answer:
(a) Intra Cytoplasmic Sperm Injection
(b) Gamete Intra Fallopian Transfer

Question 15.
Fill in the blanks to complete the schematic repre sentation.

Answer:
(a) Lippes loop
(b) Multiloäd 375
(c) LNG-20
(d) Progestasert

Question 16.
Write any four objectives of Reproductive and Child Health Care (RCH) programmes.
Answer:

1. Creating awareness among people about various reproduction related aspects.
2. Providing facilities and support for building up a reproductively healthy society.
3. Provide right information to the young so as to discourage children from believing in myths and
   having misconceptions about sex-related aspects.
4. Proper information about reproductive organs, adolescence and related changes, safe and hygienic sexual practices, sexually transmitted diseases.

Question 17.
‘Now-a-days, the world is facing a problem of increased rate of species extinction due to huma
activities’. Write major causes of biodiversity losses.
Answer:

1. Habitat loss and fragmentation
2. Over-exploitation
3. Alien špecies invasion
4. Co-extinctions

Question 18.
Drug/Alcohol abuse results in immediate and far reaching effects. Write some effects you have studied.
Answer:

1. Use of alcohol causes stomach ulcer and pancreatitis.
2. Causes lack of interest in personal hygiene, isolation, depression, aggressiveness etc.
3. Causes deteriorating relationship with family and friends change in eating and sleeping habit.
4. The excess usage of alcohol causes liver cirrhosis and damage to nervous system.

Question 19.
Evolution of Darwin finches in an example for ‘Adaptive radiation’.
(a) What is meant by ‘Adaptive radiation’?
(b) Give two other example for organisms those exhibitAdaptive radiation.
Answer:
(a) The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of habitat is called adaptive radiations.

(b) Marsupia[ mammal in Australia & Placental mammals.

Question 20.
Write any four differences between Spermatogenesis and Oogenesis.
Answer:

Spermatogenesis	Oogenesis
1. Four sperms from one primary from spermatocyte.	1. It is the process of formation of ovum oregg.
2. It is the process of formation of sperms.	2. It take place in ovary.
3. It take place in male.	3. It take place in female.
4. It take place in testis.	4. Starts in embryonic stage.

Question 21.
Micrograph of Red blood cells of two persons (A) and (B) are shown below. Person B is affected with
a specific genetic disorder.
(i) Identify the genetic disorder.
(ii) Write reason for this disorder.

Answer:
(i) Sickle-cell anemia
(ii) The defect is due to substitution of glutamic acid (Glu) by valine (Val) at sixth position of beta globulin chain of haemoglobin.

Question 22.
In women, some hormones are secreted only durng pregnancy. Name any such hormones.
Answer:

1. Human chorionic gonadotropin (hCG)
2. Human placental lactogen (hPL)

Question 23.
Match following:

A	B
i. L.H. Surge	Fertilisation
ii. Leydig cells	Nutrition to
iii. Ampullary-isthmic junction	Spermatids
iv. Sertoli cells	Ovulation

Answer:

A	B
i. L.H. Surge	Ovulation
ii. Leydig cells	Androgens
iii. Ampullary-isthmic junction	Fertilisation
iv. Sertoli cells	Nutrition to Spermatids

Question 24.
“Species diversity is greater in tropical regions than in temperate regions.” Give reasons.
Answer:
Tropical environment are more constant and predictable. Solar energy is more in tropical area than temperate area.

Question 25.
Vaccines are given to children at various stages of their development.
(a) What is meant by ‘vaccine’?
(b) Write the principle of vaccination.
Answer:
(a) Vaccines are preparation of antigenic proteins of pathogen or inactivated or weakened pathogen
(b) Property of memory of the immune system

Question 26.
Match following:
Answer:

1. 1^st month – Heart sound is noticed using stethescope.
2. 2^nd month – Limbs and digits are developed in foetus
3. 5^th month – First movement of foetus is observed
4. 6^th month – Eye lids are separated and eye lashes are formed

III. Each question from 27 to 31 carries 3 scores. (5 × 3 = 15)

Question 27.
(a) Identify the equation related with genetic equilib rium given below:
p² + 2pq + q² = 1
(b) Write the factors affecting genetic equilibrium resulting in evolution.
Answer:
(a) Hardy Weinberg Equilibrium
(b) Gene flow ,Genetic drift, Mutation and Natural selection

Question 28.
LH and FSH play significant role in spermatogenesis.
(a) Write the funchons of LH and FSH in spermato genesis.
(b) Write a single term used to denote LH and FSH together.
Answer:
(a) LH – Act on the Leydig cell and stimulate t he production of and rogens
FSH – Acton Sertoli cells and stimulates some factors which help in spermatogenesis.

(b) Gonadotropins

Question 29.
Figure of ‘lac operon’ in the absence of lactose (inducer) is given below. Draw the diagram of ‘lacoperon’ in the presence of lactose and label it.

Answer:

Question 30.
SexuallyTransmitted Diseases (STDs) are seen to be high among people with age group 15 -24 yrs.
(a) Write the names of any 4 STDs
Answer:
(a)

1. AIDS
2. Genital Herpes
3. Genital Warts
4. Trichomoniasis

(b)

1. Avoid sex with unknown partner
2. Always use condoms during coitus
3. In case of doubt consult a doctor for diagnosis and treatment

Question 31.
‘Incomplete Dominance’ is an example for deviation from Mendelian Inheritance. Illustrate with example.
Answer:
It is the inheritance in which the heterozygous offspring show intermediate character between two parents. Cross given below shows the genotypic and phenbtypic ratio in F₁ and F₂ generation.

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf March 2022 to improve time management during exams.

Kerala Plus Two Zoology Question Paper March 2022 with Answers

A. Answer any three questions from 1 to 4. Each carries 1 score. (3 × 1 = 3)

Question 1.
Homologous organ: Divergent evolution:: Analogous organ:
Answer:
Convergent evolution

Question 2.
Expand the term ZlFT.
Answer:
Zygote Intra Fallopian Transfer

Question 3.
Mitotic division of zfgote results in the formation of blastomeres is called
Answer:
Cleavage

Question 4.
Name the enzyme that joins the DNA fragments in dis-contthuous strand during replication.
Answer:
DNA Ligase

B. Answer all questions from 5 to 6. Each carries 1 score.

Question 5.
The term ‘Biodiversity’ was popularised by the scientist ______
Answer:
Edward Wilson

Question 6.
The first antibiotic discovered was ______
Answer:
Penicillin

Part-II

A. Answer any two questions from 7 to 9. Each carries 2 scores.

Question 7.
‘Codon AUG is known as initiator codon.
(a) Name the amino acid coded by AUG.
(b) Write any two stop codons
Answer:
(a) Methionine
(b) U, UAG

Question 8.
Write the functions of the following
(a) Leydig cells
(b) Corpus luteum
Answer:
(a) Secrete testicular hormones called androgens or Testosterone.
(b) Secretes progesterone

Question 9.
Match the following:

(A)	(B)
i) Trtchoderma	a. Citric acid
ii) Monascus purpureus	b. Ethanol
iii) Saccharomyces cerevisiae	c. Cyclosponn A
iv) Aspergillus niger	d. Statin

Answer:

A	B
Trichoderma polysporum	a. Cyclosporin A
Monascus purpureus	b. Statin
Sacoharomyces cervisiae	c. Ethanol
Aspergillus niger	d. Citric acid

B. Answer any two questions from 10 to 13. Each carries 2 scores. (2 × 2 = 4)

Question 10.
Choose the correct terms from the bracket to fill in the blanks and complete the table: (Bigbang theory, Miller’s experiment, Lamarkism, Darwinism)

(A)	(B)
i) Natural selection	a ____
ii) Chemical evolution	b ____
iii) Origin of Universe	c ____
iv) Use and Disuse of organs	d ____

Answer:

(A)	(B)
i) Natural selection	Darwinism
ii) Chemical evolution	Miller’s experiment
iii) Origin of Universe	Bigbang theory
iv) Use and Disuse of organs	Lamarkism

Question 11.
Write any four ill-effects of Drug/Alcohol abuse.
Answer:

1. Causes heart failure and hypertension.
2. Use of alcohol causes stomach ulcer and pancreatitis.
3. Causes lack of interest in personal hygiene,solation, depression , aggressiveness etc.
4. Causes deteriorating relationship with famil y and friends change in eating and sleeping habit etc.

Question 12.
(a) Name the cap-like structure present in sperm head.
(b) Write its function.
Answer:
(a) Acrosome

(b) Acrosome is filled with lytic enzyme that helps in the penetration of sperm in wall iayers of ovum  that leads to fertilisation

Question 13.
(a) Distinguish between Male heterogamety and Female heterogamey.
(b) Write one example for each.
Answer:

Male heterogamety	Female heterogamery
Here males are heterozygous (XY/XO)	Here females are heterozygous (ZW)
Mates produce two types of gamete	Females produce two types of gamete
Type of male gamete/sperm will determine the sex of the progeny	The type of female gamete/egg will determine the sex of the baby
This type of mechanism seen in	This type of mechanism seen in
. Human male	. Birds
. Grass hopper

(b) Male heterogamety – Different type of chromo some constitution in Male.
Eg :- Human or Drosophila
Female heterogamety -Different type of chromo some constitution in female
Eg :- Birds

Part – III

A. Answer any three questions from 14 to 17. Each carries 3 scores. (3 × 3 = 9)

Question 14.
“Allele frequencies in a population are stable and is constant from generation to generation.”
(a) Name the principle
(b) Mention any four factors those affect this principle.
Answer:
(a) Hardy Weinberg Principle
(b) Gene flow mutation genetic recombination natural selection

Question 15.
“Sex of a child is determined by father”. Substantiate the statement.
(b) Name any four STDs.
Answer:
In human, the male produce two types of gametes i.e. one with X chromosome and other with Y chromosome. During fertilisation, Sperm with X chromosome fuses with egg to produce female child while sperm with Y chromosome fuses with eg to produce male child.

Question 16.
incidents of STDs are very high among the age group of 15-24 years.
(a) What is STD?
(b) Name any four STDs.
Answer:
(a) Sexually Transmitted Diseases
(b) Gonorrhoea, syphilis, genital herpes, hepatitis B,& AIDS

Question 17.
(a) Write four major causes of Biodiversity loss.
(b) Give one example for in-situ conservation and ex-situ conservation of Biodiversity.
Answer:
(a)

1. Habitat loss and fragmentation
2. Over-exploitation,
3. Alien species invasions
4. Co-extinctions

(b) In situ conservation
Eg :- Biosphere Reserves or National Park
Ex situ Conservation
Eg :- Botanical Gardens or Zoological Park

B. Answer the following question. Carries 3 scores.(1 × 3 = 3)

Question 18.
(a) Expand the term DNA. Who proposed double helical model of DNA?
(b) List out the nitrogen bases in DNA.
Answer:
(a) Deoxyribo Nucleic Acid James Watson & Francis Crick
(b) Adenine, Thyrnine, Guanine, Cytosine

Part – IV

Answer any one question from 19 to 20. Each carries 5 scores. (1 × 5 = 5)

Question 19.
(a) Expand thetermAlDS. Mention the name of virus that causes AIDS.
(b) Name the widely used diagnostic test for AIDS.
(c) List out any four practices for the prevention of AIDS.
Answer:
(a) Acquired Immuno Deficiency Syndrome

(b) ELISA Test

(c)

1. Use disposable syringe and needles.
2. Checking of blood before blood transfusion.
3. Use condom for male or female during intercourse.
4. Avoid intercourse with unknown partner.

Question 20.
Schematic diagram of a transcription unit is given below:

(a) Identify the pans A and B.
(b) What is transcription?
(c) Write the complementary DNA strand by observing the strand given below:
Answer:
(a) A – Promoter gene
B – Template strand

(b) It is the process of formation of mRNA from DNA

(c) 3 – TACGTACGTA-5

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf March 2024 to improve time management during exams.

Kerala Plus Two Zoology Question Paper March 2024 with Answers

I. Answer any three questions from 1 to 5. Each carries 1 score. (3 × 1 = 3)

Question 1.
Genes which code for a pair of contrasting traits are known as _____.
Answer:
Alleles

Question 2.
The process of copying genetic information from one strand of the DNA into RNA.
Answer:
Transcription

Question 3.
Name an. oral contraceptive for females developed by scientists at Central Drug Research Institute.
Answer:
Saheli

Question 4.
The enlarged end of penis called the glans penis is covered by a loose fold of skin called _____.
Answer:
Foreskin

Question 5.
Biodiversity is the term popularized by the sociobiologist to describe the combined diversity at all the levels of biological organization.
Answer:
Edward Wilson

II. Answer any 9 questions from 6 to 16. Each carries 2 scores. (9 × 2 = 18)

Question 6.
Differentiate between analogous organs and homologous organs and mention one example each.
Answer:

Homologous organs	Analogous organs
. Organs that have similar structure but having differentfunction	. The organs that are having similar function but differ in structure and ongins are calLed analogous organs
. Homology indioetes common ancestry.	. Analogous organ represents the convergent evolution.
. Homologous organ represents the divergent evolution.
Examples:	Examples:
. Fore limbs of whale, bat, human and cheetah.	. Wings of Butterfly and Birds.
. Hearts of Vertebrates	. Eye of Octopus and Mammals.
. Brain of Vertebrates	. Fhppers of Penguins and Dolphins
. Tendril in Cucurbits & Thom in Bougainvillea	. Tuber of Potato and Sweet Potato.

Question 7.
Observe the given diagram of male reproductive system, and identify the parts labelled as A, B, C and D.

Answer:
A – Vas deferens
B – Urethra
C – Epididymis
D – Rete testis

Question 8.
Infections or diseases which are transmitted through sexual intercourse are collectively called sexually transmitted infections.
(a) NameanytwoSTis.
(b) Suggest any two methods to prevent STIs.
Answer:
(a) Gonorrhoea
• Syphilis

(b) • Avoid sex with unknown partners
• Always use condoms during coitus.

Question 9.
Complete the following table:

Chromosomal Disorder	Karyotype	Symptoms
(A) _______	Trisomy 21	Palm is broad, Short statued
(B) _______	(C)  _______	Gynaecomastia
Turner’s Syndrome	44 + Xo	D

Answer:
A – Down’s Syndrome
B – Kllnefelter’s Syndrome
C – 47 with XXY / 44A + XXY
D – Sterile female

Question 10.
Innate immunity is non-specific type of defence, that is present at the time of birth. Which are the four types of barriers involved in innate immunity and mention one example for each.
Answer:

1. Physical Barriers
   • It includes’ the anatomical barriers like skin.
2. Physiological Barder
   • It indude body temperature Cellular Barriers
   • Phagocytic cells in our bod y such as Polymorpho-nuclear leucocytes (PMNLe neutrophils)
3. Cytokine Barriers
   • Interferons. (My one example in each)

Question 11.
Complete the following flow chart which shows the origin and evolution of man.

Answer:
A – Ram apithecus
B – Homo habilis
C – Homo erectus
D – Homo sapiens

Question 12.
A wide range of contraceptive methods are presently available.
(a) Name two surgKal methods advised for male and female partner as a terminal method to prevent any more pregnancies. (1)
(b) Give two examples for copper releasing IUDS. (1)
Answer:
(a) Male – Vasectomy.
Female – Tubectomy.
(b) CuT, Cu7 and Multiload 375 (Any two exam pies)

Question 13.
In a cross between true breeding red-flowered (RR) and true breeding white-flowered (rr) plants, the F₁ (Rr) was pink coloured.
(a) Name the inheritance pattern mentioned here. (1,4)
(b) F₁ was self-pollinated and F₂ was obtained. What is the genotypic ratio and phenotypic ratio of F₂. (1)
(c) Mention a plant which shows this inheritance. (1/2)
Answer:
(a) Incomplete dom inanc
(b) Phenotypic ratio = 1 : 2 : 1
Genotypic ratio = 1 : 2 : 1
(c) Dog flower plant or Snapdragon or Antirrhinum

Question 14.
The following diagram shows central dogma in molecular biology. Write the name of process represented asAand B.

Answer:
A – Transcription
B – Translation

Question 15.
Match the following:

A	B
Clostridium butylicum	Acetic acid
Aspergillus niger	Lactic acid
Acetobacter aceti	Butyric acid
Lactobacillus	Citric acid

Answer:

A	B
Clostridium butylicum	Butyric acid
Aspergillus niger	Citric acid
Acetobacier aceti	Acetic acid
Lactobacillus	Lactic acid

Question 16.
In a debate conducted in school, your friend said that AIDS can be transmitted through touch or physical contact.
(a) Do you agree with that statement? (1/2)
(b) Name theeclinical test used to diagnose AIDS. (1/2)
(c) How do HIV infect human body? (1)
Answer:
(a) No.

(b) ELISA- Enzyme Linked Immuno-Sorbent Assay.

(c)

1. HIV enters body and infect the Macrophages
2. RNA genome replicates to form viral DNA by Reverse transcriptase.
3. Viral DNA incorporates into host cell’s DNA.
4. Infected cells produce more and more viral particles.
5. Enters Helper T Lymphocytes (TH).
6. Replicates and produce progeny virus.
7. Attack other T cells so that T cells count decreases.
8. Immunity weakens.

III. Answer any three questions from 17 to 20. Each carries 3 scores. (3 × 3 = 9)

Question 17.
Observe the diagrammatic presentation of various events during a menstrual cycle.

(a) Identify ‘A’ and ‘B’ in graph. (1)
(b) Name two different methods of biodiversity conservation. (1)
(c) What is so special about tropics that might account for their greater biological diversity? (1)
Answer:
(a) A – Estrogen; B – Progesterone.

(b) C – Corpus luteum. It secretes a large amount of progesterone, which maintain the endometrium of uterus.

(c) Luteinizing hormone.

Question 18.
Pedigree analysis of two Mendelian disorders are shown below:
Answer:

1. Isolation of DNA
2. Digestion of DNA by restriction endonuclease enzyme
3. Separation of DNA fragments by electrophoresis
4. Blotting of separated DNA fragments into synthetic nylon or nitrocellulose membrane.
5. Hybridisation using labelled VNTR (Variable Number of Tandem Repeats) pcobe.
6. Detection of hybridised DNA fragment by autoradÍography.

Question 19.
Answer:
(a)

1. Habitat loss and fragmentation,
2. Over-exploitation,
3. Alien species invasions,
4. Co-extinctions

(b) In Situ Conservat ion – Ex Situ Conservation

1. Speciation is generally a function of time.
2. Tropical latitudes have remained relatively undisturbed for millions of years and thus had a long evolutionary time for species diversification.

Question 20.
Pedigree analysis of two Mendelian disorders are shown below:

(a) Identify the trait represented asAand B.(1)
(b) Which is the symbol for consanguineous mating used in pedigree analysis? (1)
(c) What do you mean by pedigree analysis?(1)
Answer:
(a) A – Autosomal dominant trait/ Myotonic dystrophy
B – Autosomal recessive trait I Sickle cell anaemia

(b)

(c) Analysis of a genetic trait in a several generations of a family is called pedigree analysis.

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf March 2023 to improve time management during exams.

Kerala Plus Two Zoology Question Paper March 2023 with Answers

I. Answer any 3 questions from 1-5. Each carries 1 score. (3 × 1 = 3)

Question 1.
Select the odd one. Justify your selection. (Rete testis, Vasa efferentia, Fallopian tube, Vas deferens)
Answer:
Fallopian tube.

Question 2.
Write the Central dogma in Molecular biology.
Answer:
Genetic information flows from DNA-» mRNA —» Protein

Question 3.
Which microbe is called baker’s yeast?
(A) Propionibacterium sharmanii
(B) Lacto bacillus
(C) Saccharomyces cerevisiae
(D) Aspergillus niger
Answer:
Saccharomyces cerevisiae

Question 4.
Pick out the correct pair of disease and its pathogen:
(A) Filaria – Rhino virus
(B) Typhoid – Streptococcus
(C) Malaria – Plasmodium
(D) Ascariasis – Entamoeba
Answer:
Malaria-Plasmodium.

Question 5.
Identify two ex-situ conservation approaches of or-ganisms from the following list:(Zoological Park, Biosphere Reserve, National Park, Botanical Garden)
Answer:
Zoological Park, Botanical Garden.

II. Answer any 9 questions from 6-16. Each carries 2 scores.

Question 6.
Placenta also act as an endocrine tissue and produce several hormones.
(A) Name any two placental hormones.
(B) Write two functions of Placenta, (other than endocrine function)
Answer:
(A) 1. Human chorionic gonadotropin
2. Human placental lactogen

(B) It facilitates the supply of oxygen and nutrients to the embryo.
• It helps to remove CO₂ and excretory wastes produced by the embryo.

Question 7.
The graph given below shows the ovarian events and ovarian hormone levels during menstrual cycle

(i) Name hormones A and B.
(ii) Write the ovarian events during luteal phase.
Answer:
(i) A-Progesterone
B – Estrogen.

(ii) The remaining parts of the Graafian follicle transform as the corpus luteum.
• It secretes large amounts of progesterone essential for maintenance of endometrium.

Question 8.
What are lUDs? Name one copper releasing and one hormone releasing lUDs.
Answer:
lUD’s (Intra Uterine Devices) :-These devices that are inserted by doctor or expert nurse into the uterus through vagina.

• Copper releasing lUDs .
Eg CuT, Cu7 & Multiload 375

• Hormone releasing lUDs.
Eg Progestasert, LNG -20 (Any one example in each)

Question 9.
Match the following:

Genetic Disorders	Genetic Reasons
Klinefelter’s syndrome	21st Trisomy
Down’s syndrome	Lack of one ‘X’ chromosome in females(XO)
Turner’s syndrome	Due to autosomal recessive trait
Phenylketonuria	Presence of an extra X chromosome in males (XXY)

Answer:

Genetic Disorders	Genetic Reasons
Klinefelter’s Syndrome	Presence of an extra X chromosome in males (XXY)
Down’s Syndrome	21st Trisomy.
Turner’s Syndrome	Lack of one ‘X’ chromosome in female (XO).
Phenylketonuria	Due to autosomal recessive trait.

(i) A-Terminator gene B – Coding strand
(ii) It determines the base sequence in mRNA

Question 10.
Schematic representation of a transcription unit is given;

(i) Fill up the missing parts A and B.
(ii) Write the role of template strand in transcription.
Answer:
(A) The organs that are having similar function but differ in structure and origins.
(B) Eyes of octopus and mammals, Wings of butterfly and birds

Question 11.
(A) Define Analogous organs.
(B) Identify analogous organs from the given ex-amples :
(i) Eyes of octopus and mammals
(ii) Vertebrate hearts
(iii) Wings of butterfly and bird
(iv) Forelimbs of Cheetah and Human
Answer:
(A) The organs that are having similar function but differ in structure and origins.
(B) Eyes of octopus and mammals, Wings of butterfly and birds

Question 12.
Using the given terms in brackets, complete the following evolutionary stages of man :
(Homo sapiens, Homo habilis, Homo erectus, Australopithecines)

A – Australopithecines
B – Homo habilis
C- Homo erectus
D – Homo sapiens

Question 13.
Differentiate between Active immunity and Passive immunity.
Answer:

• Active Immunity
  1. Antibodies are produced in the host body when pathogen is entered into body.
  2. It shows the property of memory.
• Passive Immunity
  1. Ready-made anti-bodies are directly injected into the body.
  2. Memory property is absent.

Question 14.

Write some important measures that would be use-ful for the prevention and control of alcohol and drug abuse among adolescents.(Write relevant four points)
Answer:

1. Avoid undue pressure in adolescence
2. Proper education and counselling
3. Providing help from parents
4. Peer group looking for the danger sign

Question 15.
Two bioactive molecules are given :
(i) Cyclosporin-A
(ii) Streptokinase
(A) Name the microbe,which produces these bioactive molecules.
(B) Write its use.
Answer:
(A) Trichoderma polysporum. Used as Immunosuppressive agent.
(B) Streptococcus. Used as clot buster (Removing the clot)

Question 16.
A figure showing the global biodiversity of inverte-brates and vertebrates are given.

(A) Identify the most diverse groups of vertebrates and invertebrates.
(B) What are the three important levels of biodiversity?
Answer:
(A) Vertebrates – Fishes Invertebrates – Insects
(B) Genetic Diversity, Species diversity, Ecological diversity

III. Answer any 3 questions from 17 to 20. Each

Question 17.
(A) What are STIs?
(B) Give two examples!
(C) Write any two preventive measures of STIs.
Answer:
(A) Sexually Transmitted Infections
(B) Gonorrhoea and Syphilis.
(C) Avoid sex with unknown partners. Always use condoms during coitus.

Question 18.
Cross between Red flower (RR) and white flower (rr) bearing plants of Snapdragon produced all plants with pink flowers in F₁ generation.
(A) Name the genetic phenomenon of this cross.
(B) Illustrate F2 generation of this cross using Punnet square.
Answer:
(A) Incomplete Dominance
(b)

Question 19.
The given illustration shows ‘Evil Quartet’ of biodiversity loss :

(i) Fill up A’ and ‘B.
(ii) Explain Co-extinction and Alien species invasion with suitable examples.
Answer:
(i) A-Habitat loss and fragmentation B – Over-exploitation.

(ii) Co-extinction – When a species becomes extinct, the plant and animal species associated with it also become extinct.
Eg plant and its pollinator, Host and its parasites.

Alien species invasion – New species introducing into a geographical region is called alien species. It cause decline or extinction of indigenous species.

Eg : – Nile Perch introduced into Lake Victoria in East Africa lead to extinction of Cichlid fish in the lake.

Question 20.
Explain the transformation experiments performed by Frederick Griffith with bacteria Streptococcus
Pneumoniae.
Answer:
Streptococcus pneumonia bacterium has two strains S strain cause Pneumonia. R strain did not cause Pneumonia.

Steps in Griffith’s experiment

S-strain Injected into mouse → Mouse dies of pneumonia.

R-strain → Injected into mouse → Mouse lives Heat killed S-strain → Injected into mouse → Mouse lives.
Heat killed S-strain + Live R-strain → Injected into mouse Mouse → dies

Griffith’s postulated that some ‘transforming principle’ transferred from the heat- killed S-strain to R-strain and make them virulent.

Teachers recommend solving Kerala Syllabus Plus Two Botany Previous Year Question Papers and Answers Pdf March 2024 to improve time management during exams.

Kerala Plus Two Botany Previous Year Question Paper March 2024

I. Answer any 3 questions from 1-4. Each carries 1 score. (3 × 1 = 3)

Question 1.
Choose the correct answer and fill up the blanks. In grasses the monocot embryo contains single cotyledons named. (Plumule, Radicle, Scutellum, Coleorhiza)
Answer:
Scutellum.

Question 2.
In Recombinant DNAtechnology, precipitated DNA can be separated by ______.
Answer:
Spooling

Question 3.
A single stranded DNA or RNA tagged with radioactive molecule is called
(a) Plasmid
(b) Probe
(c) Clone
(d) Vector
Answer:
b) Probe.

Question 4.
Sun is the only source of energy for all ecosystem on earth. But one exception. What is that?
Answer:
Deep sea hydro-thermal ecosystem I Deep Sea.

II. Answer any 9 questions from 5-15. Each carries 2 scores. (9 × 2 = 18)

Question 5.
Observe the diagram of Pollen grain given below and answer the questions.

(a) Identify the cell ‘A’ and ‘B’.
(b) Write the two features of ‘A’.
Answer:
(a) A – Vegetative cell
B – Generative cell

(b) Vegetative cell is bigger / has abundant food reserve I has large irregularly shaped nucleus. (Any two features)

Question 6.
Name the special cellular thickening present in the synergid at micropylar end. Write its function.
Answer:
Filiform apparatus. It plays an important role in guiding the entry of pollen túbe into the synergids.

Question 7.
What are the two core techniques that enabled the birth of modern biotechnology?
Answer:
Genetic engineering. Bioprocess engineenng I Chemical engineering processes.

Question 8.
Explain any two methods by which recombinant DNA can be directly introduced into the host cell.
Answer:
Microinjection : Direct injection of recombinant DNA (rDNA) into the nucleus of an animal cell is called microinjection  It is the rDNA transfer method for animal cell.

Biolistics : Bombardment of plant cell with high velocity micro particle of gold or tungsten coated with DNA is called biolistics I It is the rDNA transfer method for plant cell.

Question 9.
The first trarisgenic cow p roduced human protein enriched milk. Name the cow and the
protein found in milk.
Answer:
The first transgenic cow is Rosie. The protein is aipha-lactalbumin I Human protein.

Question 10.
Match the following

A	B
1. Biopiracy	A. ADA deficiency
2. Gene Therapy	B. Basmathi Rice
3. RNA Interference	C. Cry gene
4. Bacillus thuringiensis	D. Melodegynae incognita

Answer:

A	B
1.Biopiracy	Basmati Rice
2. Gene Therapy	ADA deficiency
3. RNA Interference	Meloidogyne incognitia
4. Bacillus thurengiensis	Cry gene

Question 11.
the following graph shows two types of population growth curves.

(1) Name the growth curve ‘a’ and ‘b’.
(2) What does ‘K’ stands for?
Answer:
(1) a) Exponential growth I J shaped curve I Geometric growth model.
b) Logistic growth / Verhulst-Pearf Logistic Growth I Sigmoid Growth I S-shaped curve.

(2) K – Carrying capacity.

Question 12.
Parasites evolved special adaptations to live on host. What are they?
Answer:

• The loss of unnecessary sense organs
• presence of adhesive organs or suckers to cling on to the host
• loss of digestive system
• high reproductive capacity.

Question 13.

The figure depicts pyramid of energy.
(a) Pyramid of energy is always upright, can never be inverted. Justify
(b) Which are the other two ecological pyramids?
Answer:
(a) When energy flow from a particular trophic level to the next level some energy is lost as heat at each step. Only 10% of the energy is transferred to each trophic level from the lower trophic level according to law of 10%.

(b) Pyramid of numbers, Pyramid of biomass.

Question 14.
A list of different organism in an ecosystem are given below. Arrange them in 1^st, 2^nd and 3^rd and 4^th trophic level. (Phytoplankton, Man, Fish, Zooplankton)
Answer:
Phytoplankton → Zooplankton → Fish → Man

Question 15.
Rate of Biomass production in an ecosystem is called productivity. Productivity are divided into two, GPP and NPP.
(a) Expand GPP & NPP.
(b) Write the equation relating GPP with NPP.
Answer:
(a) GPP — Gross Primary ProductMty
NPP – Net Primary Productivity
b) GPP-R=NPR

III. Answer any 3 questions from 16 to 19. Each carries 3 scores. (3 × 3 = 9)

Question 16.
Observe the diagram and answer the following questions:

(1) Label‘a’,‘b’,‘c’and”d’.
(2) Name the diploid cell found in embryo sac.
Answer:
(1) a — Antipodals
b — polar nuclei
c — Synergids
d — Egg I Female gamete

(2) Central cell.

Question 17.
The genes of organism can be altered by Manipulation. Such organisms are called Genetically Modified Organism (GMO). List any 3 merits of G.M. Plants.
Answer:
Merits of G.M. Plants includes:

• Made crops tolerant to abiotic stress (cold, drought, salt & temperature)
• Develop pest resistance
• Helped to reduce post-harvest losses

Question 18.
Observe the figure given below:
(1) Fill in the blanks a, b, and c in the figure.
(2) Write the name of this process.
(3) What is the name of thermostable DNA polymerase enzyme used in this techniques?

Answer:
(1) a. Denaturation
b. Annealing
c. Extension.

(2) Polymerase Chain Reaction

(3) Taq Polym erase (from the bacteria Therm us aquaticus).

Question 19.
Given below are examples of some population interactions. Identify and define the interaction.
(a) Cattle egret and grazing cattle
(b) Fig tree and wasp
(c) Cuscuta growing on hedge plants.
Answer:
(a) Commensalism: It is +, O interaction In this interaction one species is benefitted and the other is neither behefitted nor harmed.

(b) Mutualism : It is +, + interaction In this interaction both the species are benefrited.

(c) Parasitism: It is +, – interaction I in this interaction only one species is benefited and the interaction is detrimental to the other species Interaction between host and parasite.