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BIOLOGY ffi»⁄À¤—⁄°

2016 (A) ( OLD SYLLABUS )

SCHEME OF VALUATION Subject Code : 36 (O/S)

Qn. No. Marks

PART - I (BOTANY)

SECTION - A

1. Adenine / Guanine / Cytosine / Thymine ( any one ) 1

2. RNA polymerase synthesizes a strand of RNA on DNA template

strand.

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3. The replacement of functioning of a faulty gene by increasing a

correct copy of the gene to cure a genetic / inherited disorder.

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4. Because golden rice is produced through recombinant DNA

technology by inserting desired foreign genes that produce

β -carotene in it.

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5. The process of movement of water/solvent molecules from the

region of higher water potential to the region of lower water

potential across a selectively / semipermeable membrane is

called osmosis.

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Code No. 36 (O/S) 2 

 

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SECTION - B 6. Features of Genetic Code :

a) Triplet in nature b) Universality c) Non-overlapping d) Degeneracy e) Commaless f) Genetic code has initiator codon g) Genetic code has terminator codons h) Genetic code is collinear.

( any four ) ( mark for each )

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7. Goals of human genome project : a) To identify all the genes present in human DNA b) To determine the nucleotide sequences of DNA of 23 pairs of

chromosomes c) To construct detailed physical and genetic maps of all base

pairs d) To acquire complete knowledge of organization, structure

and functions of human genome and store this information in databases

e) To share the knowledge and materials at global level and technology transfer to private sectors

f) To identify ethical, legal and social implications that may arise from this project. ( any two ) (1 mark each )

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8. Restriction Endonucleases/REN/ECORI/ECORV/HIND III etc. ( any one )

DNA LIGASE

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9. T. S. of Parenchyma

mark for each label

Diagram with any 4 labels

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10. Differences between Transpiration and Guttation : Transpiration Guttation

a) Loss of water in the form of vapour

b) Water vapour diffuses through stomata, cuticle, lenticels

c) Water lost is pure d) Generally takes place

during daytime e) It is a controlled process f) It has cooling effect on

plant g) Large amount of water

lost

i) Loss of water in liquid form

ii) Water droplet is removed through hydathode

iii) Water lost is impure &

contain dissolved organic & inorganic substances

iv) It takes place during night or early morning

v) It is an uncontrolled process

vi) It doesn't have cooling effect in plant

vii) Comparatively less water is lost

Any two differences

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11. The ratio of the volume of CO2 liberated to the volume of O2

taken in during respiration is called Respiratory Quotient R.Q. value for glucose = 1

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SECTION - C 12. Lactose operon in E.coli

In the absence of lactose Regulator gene codes for repressor protein. The repressor protein binds to operator and prevents the binding of RNA polymerase to promoter. Hence transpiration of structural genes is blocked. This is referred as switching off of lac operon

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Code No. 36 (O/S) 4 

 

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In the presence of lactose, When lactose is added to the medium lactose molecule acts as inducer. Inducer binds to repressor and forms inducer-repressor complex. Hence repressor cannot bind to operator region. As a result transcription of structural genes occur, followed by translation. This results in the synthesis of β -galacosidase, galactoside permease and transacetylase. This is referred as switching on of lac operon.

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13. Steps Involved in DNA fingerprinting : a) Collection of biological samples like blood stain, hair,

semen, skin cells, mouth swab, cells of bone marrow or any body tissue. Collection of blood samples from suspects.

b) Extraction of DNA c) Amplification of DNA by PCR d) The fragmentation of DNA by using REN e) Separation of DNA fragments by Gel electrophoresis f) The DS DNA is treated with alkali to obtain single stranded

DNA g) Transferring the DNA to nylon or nitrocellulose membrane

(southern blotting) h) Adding the Radioactive labelled probes to hybridize with

specific nucleotide sequences i) X-ray film is exposed to Nitrocellulose membrane. Autoradiography j) The X-ray sheet developed is analysed for similarity or

differences in band pattern.

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14. Characteristic features of Meristematic tissues : a) The cells of meristems are rapidly dividing cells b) The cells are spherical, polygonal or rectangular in shape c) Cells are compactly arranged with intercellular spaces d) The cells are interconnected by plasmodesmata e) The cell wall is thin and primary cell wall is made up of

cellulose & hemicellulose. Sec. wall is absent f) Cytoplasm is dense. Vacuoles are small or absent g) Cell organelles are absent, chloroplast is in proplastid

stage h) Stored food material or ergastic substances are absent.

( any five )

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15. Transpiration pull theory : This theory is based on the physical properties of water, such as a) Cohesive force : The mutual force of attraction between

water molecules b) Adhesive force : Water molecules tend to attach to the wall

of xylem vessels c) As a result there is a continuous unbroken column of

water is present in the xylem d) Transpiration Pull : Water evaporates from mesophyll cells.

This results in the decrease of water potential of mesophyll cells. As a result water from cell to cell and ultimately it causes the movement of water from xylem. This exerts a pull and puts the water in the xylem under a state of tension. Due to the presence of unbroken column of water in xylem, the water is drawn / pulled upwards.

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16. Blackman's law of limiting factors : "When a process is conditioned to its rapidity by a no. of separate factors, the rate of the process is limited by the pace of the slowest factor." External factors affecting photosynthesis : a) Light : Light is the source of energy for photosynthesis.

The quality, intensity and duration of light controls the process of photosynthesis. The increase in the intensity of light up to optimum level increases photosynthesis,

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Code No. 36 (O/S) 6 

 

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beyond this, the photo oxidation occurs resulting in the destruction of chlorophyll. The maximum photosynthesis occurs in red, blue wavelengths.

b) Temperature : Increase in temperature increases the rate of photosynthesis from 0° to 40°C. Beyond 40°C rate of photosynthesis decreases due to denaturation of enzymes.

c) CO2 : It is the raw material for photosynthesis. The

atmosphere has 0·03% of CO2. If the CO2 concentration

raises up to 0·1% the rate of photosynthesis increases. Beyond this level or further increase in CO2 concentration

induces stomatal closure. d) Water content : The process of photosynthesis depends on

the availability of water. Decrease in water supply decreases the rate of photosynthesis.

e) Oxygen : High concentration of oxygen has an inhibitory effect on photosynthesis — Warburg effect.

f) Mineral elements : Elements like Mg, Fe, Cu, Cl, Mn, P are closely associated with important reaction of photosynthesis. Here deficiency of these minerals reduces the rate of photosynthesis.

( any four )

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17. Physiological roles of Auxins : a) Cell division and cell elongation b) Apical Dominance c) Root growth / Root formation d) Development of seedless fruit — Parthenocarpy e) Prevention of abscission layer formation f) Stimulating tropic movements due to the accumulation of

Auxin g) Nucleic acid synthesis h) Xylem differentiation i) Shoot and root growth.

( explaining any five ) ( 1 mark for each )

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I. 18. SECTION – D Krebs' Cycle :

( Mentioning enzymes not required )

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19. a) Because the non-coding sequences called introns have to

be removed from hnRNA.

b) Because the surface of explants may be germs / microbes

that multiply and inhibit the growth of callus.

c) Because, they contain arenchyma.

d) Because wooden doors and shutters imbibe water and

swell.

e) Because synthetic cytokinins induce cell division / callus

formation.

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Code No. 36 (O/S) 8 

 

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II. 20. T. S. of Dicot Root

Labelling mark each — 8 labels

Neat diagram

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21. Ganong's Respiroscope experiment :

Aim : Demonstration of Aerobic respiration in germinating

seeds / flower buds

Procedure : Few germinating seeds / buds taken and kept in

the bulb of Ganong's respiroscope. The stem of the

respiroscope is dipoed in a beaker containing KOH solution.

The respiroscope is fitted to a stand.

Observation : There is an increase in the level of KOH in the

stem of respiroscope

Inference : Germinating seed respires aerobically and liberates

CO2 : It is observed by KOH, and hence KOH level raises.

Contd....

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Diagram :

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PART - II (ZOOLOGY) SECTION - E

22. A cross performed between F1 hybrid and its recessive parent is

called test cross.

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23. Helicobacter pylori 1

24. Exchange of respiratory gases O2 & CO2 between alveolar air and blood of alveolar capillaries is called external respiration.

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25. Ectoderm 1

26. AIDS / Acquired Immuno Deficiency Syndrom 1

SECTION - F 27. Features of Down's Syndrome :

a) Mental retardation b) Slanting eyes with epicanthic fold of skin in eyelid c) Flattened nose bridge, mongoloid face d) Small opened mouth e) Short and broad neck f) Congenital heart defects g) Unilateral or bilateral palm crease.

( any two )

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Code No. 36 (O/S) 10 

 

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28. Anthropocentric causes for biodiversity depletion : a) Urbanization b) Expansion of agriculture c) Deforestation d) Pollution e) Acidification of soil and water f) Mining activity g) Desertification h) Loss of soil fertility.

( any four )

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29. a) Afforestation : The large scale planting of tree species in uncultivated land areas to develop forests.

b) Mulching : The covering of soil surface to protect roots of the crops with materials like pieces of straw, leaves, maize stalk, cotton stalk, potato tops etc. to conserve soil moisture.

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30. Glycogenesis : The process of conversion of glucose to glycogen Glycogenolysis : The process of breaking down the glycogen into glucose.

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31. Function of B-lymphocytes and T -lymphocytes : B-lymphocytes : On exposure to antigen they become active and multiply into plasma cells that secrete antibodies. T-lymphocytes : The T-lymphocytes directly attack abnormal cells and kill them. The T-lymphocyte stimulates phagocytic activity in macrophages. The T-lymphocyte also stimulates B-cells to produce plasma cells.

( any one )

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32. Functions of placenta : a) Placenta helps in the transport of oxygen and nutrients

from maternal side to foetus b) Placenta helps in the transport of CO2 and wastes from

foetus c) It secretes hormones like progesterone, relaxin, HcG d) It stores calcium, lipids, iron, glycogen and supply to

foetus e) It acts as a barrier and prevents the entry of bacteria into

foetus. ( any four )

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33. SECTION – G Mendel's dihybrid cross experiment :

Schematic representation

Ratio

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34. a) Global warming : Increase in the mean temperature of earth

surface due to the emission of greenhouse gases.

Greenhouse gases : CO2, CH4, N2O, CFC, water vapour

( any two )

b) Endemic species : A species that is confined to a particular

geographical region and found nowhere else.

Example :

Lion tailed macaque, Nilgiri leaf monkey, Brown palm

civet, Nilgiri Tahr, Brown antlered deer, Asiatic wild ass,

Salim Ali's fruit bat, Kerala rat, Indian giant squirrel, Red

giant squirrel, Hornbill.

( any one )

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Code No. 36 (O/S) 12 

 

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35. Nephron :

8 labels

Neat diagram

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36. Role of following enzymes indigestion : Salivary amylase : Salivary amylase acts on starch and converts it into Maltose (Disaccharide) Starch Salivary Amylase Disaccharide (Maltose) Pepsin : Pepsin acts on proteins and convert them into proteoses and peptones Starch Pepsin Proteoses + Peptones Pancreatic lipase : Pancreatic lipase acts on emulsified fats and converts them into fatty acid and glycerol Emulsified Fat Pancreatic lipase Fatty acid + Glycerol Carboxypeptidase : Carboxypeptidase acts on polypeptide and releases Dipeptides, Tripeptides, Aminoacids Polypeptide Carboxypeptidase Dipeptide + Tripeptide + Amino acid Sucrase : Sucrase acts on sucrose and splits it into a molecule of glucose and a molecule of fructose. Sucrose Sucrase Glucose + Fructose

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37. a) i) Body Temperature : Hypothalamus ii) Body Balance : Cerebellum b) i) Ovulation : Luteinising hormone (LH) ii) Parturition : Oxytocin iii) Lactation : Prolactin / Luteotrophic hormone

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38. Double circulation in man : Pulmonary circulation : In this, deoxygenated blood from right ventricle is carried to the lungs by pulmonary artery. The oxygenated blood is then brought to left atrium by four pulmonary veins. Systemic circulation : In this oxygenated blood from left ventricle is drained out by aorta and supplied to all parts of the body. The deoxygenated blood from upper part of the body is brought by superior venacava and lower part of the body by inferior venacava to the right artrium. ( only representing the scheme 2 marks )

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I. 39.

SECTION – H Spermatogenesis : Spermatogenesis occurs in three phases : a) Multiplication phase : In this, primordial cells divide

mitotically and increase in number and are called spermatogonia.

b) Growth phase : The diploid B spermatogonia undergoes growth for a brief period. The enlarged cells are called primary spermatocytes.

c) Maturation phase : The diploid spermatocytes undergo meiosis. The first meiotic division results in two equal sized cells called secondary spermatocytes. the second division results in four equal sized cells called spermatids. Spermatids transform into sperms.

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Code No. 36 (O/S) 14 

 

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40. a) Because in Mirabilis jalapa, the gene for red colour

expresses incompletely in the presence of gene for white

flower resulting in the production of pink flowers in F1

generation.

b) Because the population of Red panda is critically very low

and thus facing high risk of extinction.

c) Because origin and conduction of heartbeat occurs in the

specialized cardiac muscle fibres present in the

myocardium layer of wall of heart.

d) Because tears contain lysozymes that kill bacteria and

avoid infection.

e) Because the entire zygote divides into two blastomeres.

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II. 41.

V.S. of human heart :

Any 8 labellings mark each

Diagram

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42. Striated Muscle : a)

any 4 labels mark for each

b) Macrophage, Fibroblast, Mast cell, Plasma cells, Adipocytes ( any four )

c) Benedict's test.

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