SUB: BIOLOGY SAMPLE PAPER 01CLASS - XII

Time: 3 Hours MM: 70 Marks

General instructions:

(i) All questions are compulsory.(ii) This question paper consist of four section ABC and D.

Section A contains 8 questions of one mark each. Section B is of 10 questions of two marks each.Section C is of 9 questions of three marks each andSection D is of 3 questions of five marks each.

(iii) There is no overall choice. However an internal choice has been provided in one question of two marks, one question of three mark and all three question of five marks. A student has to attempt only one of alternatives in such questions.

(iv) Wherever necessary the diagrams drawn should be neat and properly labeled.

SECTION – A

1. Name the ecological pyramid that can be inverted in a tree eco system and an aquatic ecosystem. 1

2. A human trematode parasite depends on hosts to complete its life cycle. Give name them. 1

3. In test tube, where is zygote transferred before to reach upto 8 blastomears! Name this technique. 1

4. How did non-virulant strain become virulent in Griffth’sexperiment? 1 5. At what stage of life is oogenesis initiated in human female life? How will your

characterised a tertiary follicle. 1

6. Why bottle fruit juices are clearer as compared to made at home. 17. A female human is sterile as rudiment overies. Give its chromosomal composition and

genetic disorder. 1 8. State the uses of Nucleopolyhydrovirus with respect to pest management.

SECTION – B

9. Give a diagrammatic representation of organismic response to abiotic factors like temperature. 2

10. Observe the flaw chart and fill up the blanks a b c d 2

Primary oocyte Layer of Granulosa cells

More layer of Granulosa cells and newtheca

Transform

Mature

Ovulation

11. In monohybrid cross the genotype and phenotype ratio is 1:2:1 what type of inheritance is it? Explain with example. 2

12. What is called pregnancy hormone? What is it function and source of secretion? or Draw a fertilized embryo sac showing zygote & PEN.

213. In morula stage the cell divide without any increase in size. Why? 2

Primary follicle

A

B

C

DPolar Body

14. Name the blank spaces a b c and d from the table given below 2

Microbes Scientific name Product Medical applicationFungus a B Organ transplantationc d Statin blood-cholesterol

15. Differentiates between Biodegradable and non-biodegradable waste.2

16. What is meant by H2 L2 for an antibody? Name of antibodies which are related to mother milk and allergy. 2

17. What is parbhanikranti? Explain with an example. 218. Which is the world’s most problematic aquatic weed? Why is it so?

2

SECTION – C

19. (i) Draw a pollen grain to show grain to show vegetative and generative cell. 3(ii) Why do the exine should be hard. (iii) What is the function of germpore.

20. What is genetic equilibrium? Which factors are responsible to affect this equilibrium?3

21. A di-hybrid heterozygous round, yellow seeded garden pea was crossed with double recessive plant. 3(i) What type of cross in this(ii) Work out the phenotype of progeny(iii) What principle of mendal is illustrated

Or

Describe the nature of inheritance of ABO Blood Group in human . In which way does this inheritance differ from the height of garden pea plant. 3

22. What is sewage? In which way can sewage be harmful to us? Give key difference between Primary and Secondary Sewage treatment. 3

23. (a) In which part of the human female reproductive system do the following event(i) Release of first polar body (ii) Release of second polar body (iii) fertilization

(iv) implantation 3 (b) From where do signals for parturition originate and what does maternal pituitary

release for stimulating uterine contraction for child birth.

24. Name the three RNA polymerase found in eukaryotes and mention their function. 3

25. Give the scientific name of parasite that causes malignant malaria in human body. 3 At what stage these parasites enter in human body? Trace its life cycle in human body.

26. Expand MOET. Explain the procedure of this technology in cattle improvement. 3

27. (i) Explain metastasis? Why is it fatal? 3

(ii) The lymphocytes are two type B cells & T cells why are they called so.

(iii) A person is injured by snakebites and required an urgent immune response,

what should be done.

SECTION – D

28. What is translation? Describe the synthesis of complete polypeptide from the

ribosome. 5

Or

What is DNA fingerprinting? Describe various steps and its application?

29. List the formation of rDNA? How is isolated gene of interest amplified? 5

Or

What are cloning vectors? List the feature that are required to facilitate cloning into a vectors with a sketch the E coli cloning vector PBR 322 and give importance of ampR, roP?

30. Define decomposition & describe the process & product & decomposition.5

Or

What is Evil Quartet? Explain it? How do we conserve the Biodiversity?

Sample question Paper 02 Class - XII

Class - XIISubject - Biology

Time – 3 hrs. Max. Marks – 70

General Instructions –

i) All questions are compulsoryii) The question paper consists of four sections A, B, C & D. Section A contains 8 questions of 1

mark each, Section B is of 10 questions of 2 marks each, section C has 9 questions of 3 marks each whereas section D is of 3 questions of 5 marks each.

iii)There is no overall choice. However an internal choice has been provided in one question of 2 marks, one question of 3 marks and all the 3 questions of 5 marks. A student has to attempt only none of alternatives in such questions.

iv)Wherever necessary, the diagrams drawn on should be neat and properly labeled.

SECTION – A1. If the seeds collected from hybrids are sown the plants in progeny will segregate and

do not maintain hybrid characters. How can this problem be overcomed?2. At which end do capping and Tailing of hnRNA take place?3. Initial lactating milk colustrum has antibodies IgA which protect the infant. What type

of immunity is it ?4. What is the host called that produces a foreign gene product ? What is this product

called ?5. A multinational company outside India tried to sell new varieties of turmeric without

proper rights. What is such an act referred to ?6. It is found that clown fish live along with sea Anemone. What type of interaction is

it ?7. What does mean biodiversity hotspots ?8. Which water weed grow abundantly in eutrophic water bodies and lead to an

imbalance in the ecosystems dynamics of water body i.e. introduced due to its lovely flower.

SECTION – B

9. Why is it necessary to emasculate a bisexual flower in a plant breeding programme ? Mention the condition under which emasculation is not necessary.

(a) (b)10. DNA mRNA Protein

(i) Look at the above sequence and mention the event a & b. How is this process differ in some viruses ?

11. When tall pea plants were selfed, some of the offspring were dwarf. Explain with punnet square.

12. The male fruitfly and female fowl are heteroqametic while the female fruitfly and the male fowl are homogametic. Why are they called so?

13. Identify the disease according to given symptoms & give cause for it. Blockage of intestinal passage, internal bleeding, Muscular pain etc.

14. Which morphological and biochemical features of wheat and maize resist them from insect and pests.

15. Why is an immunosuppresent drug is required during organ transplantation ? Name a bioactive molecule used as an immunosuppressive drug.

16. i. Which microbe is useful to check disease causing microbial agent.

ii. Higher production of co2 causes large holes in swiss cheese. Name the microbe responsible for it.

17. Why was insulin derived from the pancreas of slaughtered cattle and pigs not suitable for human use ? How can pro-insulin be converted into active insulin?

18. The figure given below show relative contributions of various greenhouse gases to the total global warming.

CFC a

b Co2

i. Name the gases (a) and (b)ii. Explain how increase in green house gases in earth’s atmosphere leads to

melting of ice caps.OR

Distinguish between Eurythermal& Stenothermal organisms.

SECTION – C

19. a) How do copper and hormone releasing IUD act as an contraceptives ? Explain.

b) Give one example for each copper & hormone releasing IUDs.

20. a) In which state the developing embryo get attach with utrine wall andgive term for the same.

b) Blastomeres in blastula arranged into inner cell mass and outer layer. State term for this outer cell layer.

21. The gene I has three alleles, which affect the ABO blood group (IA, IB, i). Complete the following table giving the genotype of the blood group.

Blood Group GenotypeA IAIA

ABB

ABO

Which of these alleles is co-dominant &why ?

22. How did Avery and Macleod experiment proved the biochemical nature of transforming principle in Griffith’s experiment?

23. A recombinant DNA is formed when sticky ends of vector DNA and foreign DNA join. Explain how the sticky ends are formed and get joined.

24. How is a transgenic tobacco plant protected against Meloidegyne Incognitia? Explain the procedure.

25. Why do predators avoids eating Monarch butterfly? How does the butterfly develop this protective feature?

26. How is rate of decomposition affected by temperature, oxygen and chemical composition of detritus?

27. Why are (i) Alian species invasion and (ii) loss of habitat and fragmentation are considered to be major cause of loss of biodiversity? Explain with example.

OR

Explain the cause of algal bloom in water body. How does it affect an ecosystem?

SECTION – D

28. a) Draw a labelled diagram of L.S. of a flower to show the growth of Pollentube reaching egg apparatus.

b) Pistil of a flower does not accept pollen from any other than from its ownKind. How does it happen? Explain

OR

a) When and how does placenta develop in human female?b) How is placenta connected to the embryo?c) Placenta act as an endocrine gland. Explain.

29. Explain the steps of DNA fingerprinting that will help in processing of the two blood samples A and B picked up from the crime scene.

ORA) Why is DNA molecule a more stable genetic material than RNA? ExplainB) Unambiguous, degenerate and universal are the salient features of genetic code.

Explain them.

30. a) Why does a doctor administer tetanus antitoxin and not a tetanus Vaccine to a child injured in a road accident with a bleeding wound.

b) Fill up A, B & C in given table.

Name of drug Plant source Organ system affectedA Poppy Plant CNS

Marijuana B C

ORWhat is somatic hybridization? Explain the various steps involved in the process. Mention any two uses of somatic hybridization.

CLASS-XII sample 03BIOLOGY (THEORY)

Time: 3 Hours Maximum Marks: 70

General InstructionA. This paper consists of four sections A, B, C and D.

Section-A is of 8 questions one marks each, Section-B is of 10 questions two marks each, Section-C is of 9 questions three marks each and Section-D is of 3 questions of five marks each.

B. All questions are compulsory.C. There is no overall choice. However an internal choice has been provided in one

question of 2 marks, one question of 3 marks and all the three questions of 5 marks weightage.

Attempt only one of the choices in such questions.D. Question numbers 1 to 8 are to be answered in one word or one sentence each.E. Questions numbers 9 to 18 are to be answered in approximately 20-30 words eachF. Question numbers 19 to 27 are to be answered in approximately 30 to 50 words each.G. Questions numbers 28 to 30 are to be answered in approximately 80-120 words each.H. Give neat and properly labelled diagram whenever necessary.

SECTION-‘A’

Q.1) Name the unlabelled areas ‘a’ & ‘b’ of

the pie chart representing the globalbiodiversity of invertebrates showing their proportionate number of species of major taxa. (1)

Q.2) After a successful in vitro fertilisation, the fertilised egg begins to divide. Where is this egg transferred before it reaches the 8 celled stage and what is this technique named? (1)

Q.3) How many ova will be produced by one full grown primary oocyte? (1)

Q.4)Why is the polar region not suitable for tiny humming birds? (1)

Q.5) Name the components ‘a’ and ‘b’ in the nucleotide with a purine given below:

(1)Q.6)What is heterogamety? Give an example of an organism showing it. (1)

Q.7) State the use of:a)Monascuspupureusb)Propionibacteriumsharmanii(1)

Q.8) Name two diagnostic techniques used to detect the presence of a pathogen in its early stage of infection. (1)

SECTION-‘B’

Q.9) Bougainvillea thorns &Cucurbita tendrils are homologus structures. Why do you call them homologus? Which type of evolution do they show? (2)

Q.10)A person shows unusual hypersensitive reactions when exposed to certain substances present in air .Identify the condition. Name the cells responsible for such reactions and one biochemical secreted by these cells during the reaction. Name one drug to reduce this reaction. (2)

Q.11) Fed up of a large family, a couple wanted to adopt a terminal method of contraception. Describe the process conducted by doctor in either of the cases.(male/female partner). (2)

Q.12)The flower brinjal is referred to as chasmogamus while that of bean is cleistogamuos. How are they different from each other? (2)

Q.13) Name the blank spaces a, b, c & d in the table given below: (2)Name of the drug Plant source Organ system

affectedi) a)____________ Poppy plant b)___________

ii) Marijuana c)____________ d)____________

Q.14) Honey collection improves when beehives are kept in crop fields during flowering season. Why? How do the crop plants get benefited from this practice?OR (2)How does addition of a small amount of curd to fresh milk help in formation of curd? Mention a nutritional quality that gets added to the curd.

Q.15) Name any two sources of electronic wastes. Mention any one way of each of its disposal in developing countries and developed countries. (2)

Q.16) Give the scientific term for the following: a) Interconnection of food chains.b) Mass of living material at a particular time of trophic level.c) Final community which reaches equilibrium during plant succession.d) Another term for nutrient cycle. (2)

Q.17) Name two examples of each of the following:a) Cauliflower varieties resistant to blackrot and curl blight. b) Flat bean varieties resistant to insect Pest-Jassids, aphids and fruit borer. (2)

Q.18)During the secondary treatment of the primary effluent, how does the significant decreases in BOD occur? (2)

SECTION-‘C’

Q.19) a) Mention the steps required to make bacterial cells component to take up recombinant DNA.b) Name one method to introduce alien DNA into:i) Plant cell ii) Animal cell (3)

Q.20) Each cycle of polymerase chain reaction includes three steps. Mention these steps and diagrammatically explain the process.

Q.21)a) Expand the term UTR and what does it mean?- b) Where is it located?c) What is its significance? (3)

Q.22) Study the figure given below and answer the questions that follows

i) Name the stage of human embryo, the figure represents.ii) Identify ‘a’ in the figure and mention its functions.iii) Mention the fate of inner cell mass after implantation in the uterus. (3)

Q.23) a) Expand the term ADA and what is its crucial role in human body?b) What is the cause of ADA deficiency in a person? c) Why is it that even after infusion of genetically engineered lymphocyte intothe patient suffering from ADA deficiency, cure is not permanent?

d) What could be the permanent cure? (3)

Q.24) The graph shows the organismic responseTo abiotic environmental factors. Name

the categories of animals which show the Pattern a, b, & c respectively and define each of them. (3)

Q.25) Study the given figure and answer the questions:

i) Is the trait sex linked or autosomal? Why?ii) Give the genotypes of parents.iii) Give the genotypes of affected daughter of second generation & son in third

generation.OR(3) If the sequence of coding strand in a transcription unit is written as follows: 5’ATGCATGCATAG3’

a) Write the base sequence of mRNA transcribed with polarity 5’ to 3’.b) Why transcription and translation are coupled in prokaryotes?c) Why splicing is necessary in processing of Eukaryotic hnRNA?

Q.26) What are Mycorrhizae? How do they serve as biofertilisers? (4 points) (3)

Q.27)

a) Write your observation on the variations seen in Darwin’s finches shown above.b) How did Darwin explain the existence of different varieties of finches onGalapagos Island?(3)

SECTION – ‘D’

Q.28) a) Draw a labelled sectional view of semniferous tubule of a human male.b) What is spermiation and spermiogenesis?

OR (5)

a) Draw a longitudinal section of a post pollinated pistil showing the entry of Pollentube into a mature embryosac and label any six parts of it.

b) What is the role of synergids in fertilisation?c) What is the fate of zygote and PEN?

Q.29)a) Represent diagrammatically Watson-crick model for semiconservative replication of DNA.

b) How is continuous synthesis of DNA differs from discontinuous synthesisof DNA. (Four differences)

OR (5) a) How did Hardy –Weinberg explain the allelic frequencies in a population are stable and are constant from generation to generation?b) Mention any two factors that disturb the genetic equilibrium in population. c) Fitness is the end result of the ability to adapt and get selected by nature. Explain this with reference to melanisation of moth due to industrialisation.

Q.30) a)What is meant by ozone shield and mention the unit to measure the thickness of ozone shield?b) Differentiate between Bad ozone and Good ozone.c) Name the ozone depleting substances and mention its source.d) How does it effects the ozone shield? OR (5)

a) What do you mean by detritus and litter?b) Mention the five steps by which it is decomposed?c) State any two factors affecting decomposition.d) What is the significant role of decomposition in ecosystem?

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

SAMPL PAPER 04

CLASS XII

SUBJECT- BIOLOGY QUESTION PAPER

MM –70 TIME-3 hrs

General Instructions:

1. All questions are compulsory2. This question paper consists of four sections A,B,C & D3. Section A contains 8 question of 1 marks each, section B contains 10 questions of 2

marks each, section C contains 9 question of 3 marks each & section D contains 3 question of 5 marks each

4. There are no overall choice. However, an internal choice has been provided in one question of 2 marks, 1 question of 3 marks & all the three question of 5 marks weightage. A student has to attempt only one of the alternatives in such questions.

5. Whenever necessary, the diagram drawn should be neat & properly labeled.

Section – A

1. In human females menstrual cycle occur, what cycle occur in females of rat ?2. What was the single character of DNA that went in favor of it as a better storage of

genetic information?3. Name the drugs used to reduce the symptom of allergy?4. Write the name of the bacteria that produces Bt toxins?5. Name the fungus that produces cyclosporin-A.6. If a strands of DNA having base sequence TACATC produces mRNA by transcription,

what amino acid will be there after translation.7. What is the no. of cell and nucleus in a typical matured embryo sac at maturity?8. Mention two possible reasons in favour of the survival of pouched mammals in Australia.

SECTION-B

9. An orchid called Rasna grows on mango plants and survive there –what is the

interaction between them and why?

10. What is Hardy-Weinberg’s principle? Mention any two factors that affect it.

11. “As long as mothers breast feed their children fully, the chances of conception is

almost nil”-What is it known as? How long it can be followed? Mention one its

importance also.

12. (i) What are the two amino acid residues that makes histones positive charge.(ii) In capping what is added to the 5’-end of hnRNA.

OR

Name the type inheritance in which the genotypic ratio is the same as the

phenotypic ratio also give the ratio.

13. What is bio magnification? Name two chemicals that can be cause biomagnification.

14. What is PEN? How it undergoes changes become a fully formed endosperm?15. Name the nematode that caused great reduction in tobacco yield. Mention in brief

the strategy adopted to prevent this attack.16. Name two greenhouse gases. What is meant by El-ninoeffect ?17.

CROP VARIETY INSECT/PEST

A PusaGaurav Aphids

Flat bean Pusasem B

C Pusa A-4 D

Above table has some crops that are insect pest resistance. Fill upto A,B,C&D

with suitable terms.

18. Define the term Biodiversity. How can we conserve our biodiversity?

Section-C

19. Name the organism that causes ringworm. Give the symptoms the mode of transmission of the agent.

20. In some species the diploid egg cell is formed without reduction division and develops into embryo without fertilization

(a) What is the process known as?(b) What do we call it if more than one embryo is formed within a seed?(c) How is the process can help a farmer to avoid costly hybrid seeds?

21. What is biofertilizer? How do we increase the nutrient quality of the soil? Name the organism used as biofertilizer in paddy field.

22. (a)Which compound is used to visualized the separated DNA in gel electrophorasis. (b)Which bacteria is used in amplification of PCR and what’s its used. (c)What is bioreactors

23. mention three major differences between spermatogenesis and oogenesis.24. (a) who finally disapproved the idea of spontaneous creation of life?

(b) Explain how the natural selection worked with the example of industrial melanism.

25. What is artificial insemination? Mention its advantages. Why do we consider out crossing is the best breeding method?

26. In one of his observations Morgan observed that the ratio obtained after a dihybrid cross show much higher proportion of parental combination that new combination among the offsprings –

(a) What process is responsible for this?(b) Why does it happen?(c) How the recombination percent used in gene maping?

OR(a) What is mutation? Mention its importance.(b) What is point mutation?

27. observe the figure of lac operon carefully & answer the questions below:

P i P O Z Y a

(a) In which condition the operon is now?(b) What is the role played by ‘X’ here?(c) Write the names of A,B,C& D?

Section-D

28. (a) What should be the characteristics for a molecule to act as genetic material? (b) How was it proved that DNA replication is semiconservative in nature?

OR

(a) When does sickle cell anaemia occur in offsprings?

X

A B C

(b) Make a cross between RrYy&rryy&mention what type of cross is it? 29. (a) Write in correct sequence the steps involved in recombinant DNA technology.

(b) What are the methods that can be adopted to insert a foreign DNA into the host

cell. Explain in brief one such method.

OR

(a) How do we recognize a transformant from a non-transformant?(b) What is the source of ‘T-DNA’?(c) Mention two advantages of molecular diagnosis over a traditional one.

30. (a) What is BOD? How can it be used to control water pollution?

(b) Give some suggestions to make your area free from solid waste & maintain a

clean environment.

OR

(a) Write the difference between Grazing food chain and detritus food chain.(b) What are ecological pyramids? Why do we consider pyramid of energy is more

reliable than the other Pyramids?

Class XII

SAMPLE QUESTION PAPER 05

BIOLOGY

General Instructions:

(i) All questions are compulsory.(ii) This question paper consists of 4 Sections A,B,C & D. Section A contains 8 questions

of 1 mark each, Section B is of 10 questions of 2 marks each, Section C is of 9 questions of 3 marks each and section D is of 3 questions of 5 marks each.

(iii) Wherever necessary, the diagrams drawn should be neat and properly labeled.

SECTION A1. The Turkey usually produces females for several generations. How is this possible?

2. The monocyte of maize plant contains 20 chromosomes. Work out the number of chromosome found in its endosperm.

3. Pick out the ancestral line of Geads from the list given below:

Ferns, herbaceous lycopods , seeds ferns and horsetails.

4. AaBb was crossed with aabb. What would be the phenotypic ratio of the progeny? Mention the term and denote this kind of cross.

5. State the use of

i) Trichoderma with respect to organ transplant.

ii)Nuclearpolyhedrovirus with respect to post management.

6. In plants, how is alien DNA introduced into the host cell?

7. Why is it essential to have ‘selectable marker’ in a cloning vector?

8. Name a molecular diagnostic technique to detect the presence of pathogen in its early stage of infection.

SECTION B

9. Study the figure given below and answer the question that follow:

a) From the above shown figure mention the stage of human embryo.b) Label a and write its function.c) Mention the fate of inner cell mass after implantation in the Uterusd) Where are the stem cells located in the embryo.

10. Fed up of large family , a couple wanted to adopt a terminal method of contraception. Describe the process conducted by the doctor in either of the cases (male/female parent)

Or

A mother of 1 year old daughter wanted to space her 2nd child, her doctor suggested cuT . Explain its contraceptive action.

11. Read the sequence of the nuleotides in the given segment of mRNA and the respective amino acid sequence in the polypeptide chain.

Polypeptide: met –phe-met proline-valine-serine

i) Write the nucleotide sequence of the DNA strand from this mRNA was transcribed.

ii )What does the last codon of this RNA stands for?

12. Describe the word responsibility of GEAC, set up of the Indian government.

13. During the secondary treatment of the primary effluent how does the significance decrease in BOD occur.

14.Name the enzyme involved in following process-

a) Inspecting the DNA length for palindromic nucleotide sequences.

b) Joining of DNA fragments.

c) Breaking the cell to release DNA and other macromolecules.

d) Repeated DNA amplification.

15. There are three lines of treatment of ADA deficiency disease

i) What is ADA?

ii) What is the best line of treatment?

16. Justify:-

i) Predation is useful too.

ii) Predators help to maintain species diversity.

17. What is EL Nino effect? Explain how it accounts for bio diversity loss.

18. What are the suggested methods of soil conservation?

SECTION C

19. The events of the menstrual cycle are represented below. Answer the question on the basis of following diagram:

i) State the levels of FSH ,LH and Progesterone simply by mentioning high or low around 13th and 14th day and 21st to 23rd day.

ii) In which of the above mentioned phases thus the egg travel to Fallopian tube.

iii) Why is there no menstruation upon fertilization?

20. Draw a labelled schematic sketch of replication fork of DNA. Explain the role of enzymes involved in DNA replication.

OR

AB and CD represent 2 strands of a DNA molecule. When this molecule undergoes replica, forming a replicate fork between A and C in its atom

i) Name the template strands for replication.

ii) Using which strand on the template, will there be continuous synthesis complementary DNA strand?

iii) Complementary to which strand will Okazaki segments get synthesized in discontinuous strands.

iv) What are Template strands and Okazaki pieces?

21. How did Urey and Miller provide the conditions of primitive earth to prove the origin of life in their experiment?

22. Who performed Blender experiment with respect to DNA? What was the objective of this experiment. Explain Blender experiment in brief.

23. Enumerate any three properties of cancer cells that distinguish them from normal cells. How do normal cells get transformed into cancer cells.

24. Expand MOET. Explain the procedure of this technology cattle improvement.

25. a) Why do organic farmers not recommend eradication of insect pest? Explain giving reasons.

b) How do ladybird beetles and dragonflies act as bio control agents?

c) Name the genus to which baculovirus belong. Mention one role in the integrated pest management programmes.

26. Draw neat diagram of simple stirred –tank bioreactor and label six parts.

27. Name the type of interaction seen in each of the following examples

i) Ascaris worms living in the intestines of humans

ii) Wasp pollinating fig inflorescence.

iii) Clam fish living among the tentacles of sea anemones.

iv) Mycorrhizzae living on the roots of higher plants

v) Orchids growing on a branch of a mango tree.

Vi) Disappearance of smallest barnacles when Balanus dominated in the coast of Scotland.

SECTION D

28. a) Draw a diagram of an enlarged view of T.S. of one microsprorangium of an angiosperm and label the following part: 1) Tapetum 2) Middle Layer 3) Endothecium 4) Microspore mother cell

b) Mention the characteristic features and function of tapetum.

c) Explain the following giving reasons-

i) Pollen grains are well preserved as fossils

ii) Pollen tablets are in use by people these days

OR

a) Why is the process of fertilization in angiosperms termed as double fertilization? Explain.

b) Draw a diagram of an angiospermic embryo sac whose fertilization is just completed. Label the parts:

i) micropylar end of the embryo sac

ii) the part that develops into an embryo

iii) The part that develops into an endosperm

iv) The degenerating cells at the chalazal end.

c) Draw a label diagram of globular embryonic stage of an angiosperm.

29. a) state the arrangement of different genes that in bacteria that is referred to as ‘Operon’.

b) Draw a schematic labeled illustration of lac operon in a ‘switched on’ state.

c) Describe the role of lactose in lac operon.

OR

a) A true breeding homogeneous pea plant with green pods and axial flowers as dominant characters, is crossed with Russian homozygous pea plant with yellow pods and terminal flowers. Work out the cross upto F2 generation. Giving the phenotypic ratios of F1 and F2 generation respectively.

b) State the Mendelian principle which can be derived from such a cross and not from monohybrid cross.

30. Answer the following –

a) Why do small animals (Mammals) of the polar region have short ears and short limbs?

b) How do organism like fungi and zooplanktons overcome the temporary short lived climatic stressful conditions?

c) Arrange the following as you observe in vertebral stratification of a forest – grass, shrubby plants, teak,Amaranth

d) Which forest is named as ‘lungs of the planet’?

e) Construct a pyramid of biomass starting with phytoplanktons. Why the pyramid is inverted?

OR

The above diagram shows a simplified biogeochemical cycle

i) Name the compound whose cycle is depicted

ii) In what way do vehicles add this compound to the atmosphere?

iii) What adverse effect does its excess have on the environment?

iv)Cite an event which depicts this effect in the modern times.

v) Suggest the ways of reducing the effect.