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Karnataka 1st PUC Biology Previous Year Question Paper March 2016 (South)

Time: 3.15 Hours
Max Marks: 70

General Instructions:

  1. The question paper consists of four parts A, B, C, and D.
  2. All the parts are compulsory.
  3. Draw diagrams wherever necessary. Unlabelled diagrams or illustrations do not attract any marks.

Part – A

Answer the following questions in one word / one sentence each: ( 10 × 1 = 10 )

Question 1.
Define Metabolism.
Sum total of all chemical reactions occurring in our body is known as metabolism.

Question 2.
What is placentation?
The arrangement of ovules within the ovary is known as placentation.

Question 3.
What are Goblet Cells?
Unicellular isolated glandular cells in the alimentary canal that secrete mucously.

Question 4.
Gram-negative bacteria do not take a stain – Give reason.
Glycocalyx envelop do not retain the primary stain, thus it is gram-negative.

Question 5.
Name the monomers of the protein molecules.
Amino acids.

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 6.
Define imbibition.
A special type of diffusion when water is absorbed by solids (colloids) causing them to enormously increase in volume

Question 7.
What is the ‘critical concentration’ of essential elements?
“Concentration of essential element below which plant growth is retarded.

Question 8.
Name the flat bone on the ventral midline of the Thorax of the Human body.

Question 9.
Define Hormone.
Hormones are Non-nutrient chemicals that act as intercellular messengers and are produced in trace amounts.

Question 10.
What are Polyribosomes?
Several ribosomes attached to a single mRNA forming a chain are Polyribosomes.


Answer any FIVE of the following questions in 3-5 sentences each, wherever applicable. (5 × 2 = 10)

Question 11.
Define species. Write the biological names of any two plants.
A group of individual organisms with fundamental similarities is known as a species. v Mangifera indica – Mango Solarium tuberosum – potato

Question 12.
Write any four characters of the virus.
Living characters:
(a) Like organisms they contain protein and nucleic acid.
(b) Like organisms they unçergo mutation.

Non – living characters:

  1. They are non-cellular.
  2. They do not show metabolism.

Question 13.
Enumerate four salient features of Pteridophytes.
(a) The main plant body is a sporophyte which is differentiated into true root, stem, and leaves.
(b) They possess well-differentiated vascular tissues.
(c) The leaves are small (microphylls) or large (macrophytes)
(d) The sporophytes bear sporangia that are subtended by leaf-like appendages called sporophylls.

Question 14.
Mention the function of the following organs.
(i) Malpighian tubules
(ii) Comb plates
(i) Excretion
(ii) Locomotion

Question 15.
Classify the chromosomes based on the position of the centromere.
(a) Metacentric
(b) Submetacentric
(c) aerocentric
(d) telocentric

Question 16.
What is a Respiratory Quotient? Mention the R.Q. value of proteins.
It is the ratio of the volume of CO2 evolved to the volume of O2 consumed to break a molecule of respiratory substrate.
RQ = \(\frac{\text { volume of } \mathrm{CO}_{2} \text { evolved }}{\text { volume of } \mathrm{O}_{2} \text { consumed }}\)
RQ of protein = 0.9

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 17.
Distinguish between Dedifferentiation and Redifferentiation
Cells that have lost the capacity of division, regaining the capacity of division at certain conditions is called Dedifferentiation.

Dedifferentiated cells lose the capacity of division, mature, and perform specific functions in redifferentiation.

Question 18.
Name any four types of Synovial joints.
Ball and socket, hinge joint, pivot joint, and saddle joint.


Answer any FIVE of the following questions in 40-80 words each, wherever applicable: (5 × 3 = 15)

Question 19.
Pigments are the basis of the classification of Algae – Justify the statement.
Pigments vary in different classes of algae, this is the basis for classification.
(a) Class: Chlorophyceae – chlorophyll a, b
(b) Class: Phaeophyceae – chlorophyll a, c, fucoxanthin.
(c) Class: Rhodophyceae – chlorophyll a, d, phycoerythrin.

Question 20.
Give the meaning of the following with an example each.
(a) Parallel venation
(b) Opposite Phyllotaxy
(c) Trimerous flower
(a) Parallel venation: Veins running parallel to each other e.g. grass, coconut, maize.
(b) Opposite Phyllotaxy: Pair of leaves arise at each node that is opposite to each other, e.g. Calatropis, guava.
(c) Trimerous flower: Floral appendages are in multiples of three e.g.: Onion, coconut.

Question 21.
Mention any six secondary metabolites of plants.
Carotenoids morphine, codeine, oils, rubber, resins.

Question 22.
Discuss the steps and the major pathways of Anaerobic respiration.
The first step of anaerobic respiration is glycolysis, in which glucose is incompletely oxidized to 2 pyruvic acid molecules with 2 ATP and 2NADH2 formed as by-products.

Pyruvic acid formed is used for alcoholic fermentation or lactic acid fermentation.

In alcoholic fermentation, the pyruvic acid is first decarboxylated to acetaldehyde liberating CO2. Later acetaldehyde is reduced to ethyl alcohol by NADH2 of glycolysis.

This process occurs in anaerobes like yeast and bacteria.

In lactic acid fermentation, the pyruvic acid is directly reduced to lactic acid by NADH2 of glycolysis. NO CO2 is liberated. It occurs in lactobacilli and skeletal musclçs.
1st PUC Biology Previous Year Question Paper March 2016 (South) 2

Question 23.
Mention the three phases of growth.
(a) Cell division or meristematic phase.
(b) Cell elongation
(c) Cell maturation.

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 24.
Describe the process of carbohydrate digestion in the small intestine.
Pancreatic juice contains pancreatic amylase which can hydrolyze starch into disaccharides.
1st PUC Biology Previous Year Question Paper March 2016 (South) 3
Succus entericus contain disaccharidases that act on disaccharides.
1st PUC Biology Previous Year Question Paper March 2016 (South) 4

Question 25.
Summarise the mechanism of transport of oxygen in the blood.
(a) Oxygen can bind with hemoglobin in a reversible manner to form oxyhemoglobin.
(b) Each hemoglobin molecule can carry a maximum of four molecules of O2.
(c) Binding of oxygen with hemoglobin is primarily related to the partial pressure of O2, partial pressure of CO2, hydrogen ion concentration, and temperature.
(d) Every 100 ml of oxygenated blood can deliver around 5 ml of O2 to the tissues under normal physiological conditions.

Question 26.
Mention any three disorders of the human excretory system.
(a) Uremia
(b) Renal failure
(c) Renal calculi

PART-D (Section – I)

I. Answer any FOUR of the following questions in 200-250 words each, wherever applicable. (4 × 5 = 20)

Question 27.
Enumerate any four salient features of class Amphibia, giving any two examples.
Class Amphibia:
The class amphibian (“Amphi-both” brain-life) includes cold-blooded vertebrates adapted to both land and water, as such they have made a “compromise between the t environments”.

  1. Amphibians are co4id blooded (Poildiotberms) aquatic or terrestrial, vertebrates with limbs, and lungs.
  2. The body is divided into head and trim (but in a few forms it is divided into head, neck, trunk, and tail).
  3. The skin is smooth without scales and is always moist (due to the presence of glands). It is highly vascularized, thus cutaneous respiration is seen in an amphibian.
  4. The paired fins of fishes are modified into limbs ¡n amphibia. Two pairs of limbs (forelimbs, and hind limbs) are present which are pentadactyl.
  5. At the head region a pair of eyes, a pair of external nostrils, mouth, and a pair of eardrums are present.
  6. The mouth is provided with teeth on one or both the jaws, and a movable tongue.
  7. Eyes are often provided with a well-developed nictitating membrane.
  8. Amphibians are devoid of the exoskeleton, but they possess a large bony endoskeleton.
  9. The digestive system is well developed.
  10. Respiration is by gills, book lungs, and skin or by the lining of the buccal cavity.
  11. The circulatory system comprises a three-chambered heart and veins. The heart has double circulation (i.e. system and pulmonary circulation) RBC are oval, biconcave, and nucleated.
  12. The nervous system has a brain and a pair of cranial nerves.
  13. The excretory system and reproductive system are associative to form a urinògenital system. The excretory system consists of a pair of mesonephric kidneys and a large urinary bladder. Presence of cloacae into which digestive, excretory, and reproductive systems open out, through the cloacal aperture.
  14. Sexes are separate. The reproductive system comprises paired gonads and products. The majority of them are oviparous and the eggs are non-Cleidoic. Fertilization is external.
  15. Development is indirect. Larva ¡s called tadpole.

Note 1: During indirect development metamorphosis takes place.
Note 2: Pedogenesis ¡s seen in a few members like Ambystoma, where the development of ova into a young one takes place.

Limbless amphibians – Ichthyophis.
Tailed amphibians – Salamander, Newts, and Necturus.
Tailless amphibians – Frogs, Toads (Bufo, Rana, Hyla).

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 28.
Draw a neat labeled diagram of T.S. of Dorsiventral leaf.
Anatomy of a Dicot leaf or Dorsiventral leaf:
1st PUC Biology Previous Year Question Paper March 2016 (South) 5

Question 29.
Explain the structure of chloroplast with a neat labeled diagram.
1st PUC Biology Previous Year Question Paper March 2016 (South) 6
Electron microscopic structure of the chloroplast

Chlorophyll-containing plastids are called Chloropbsts. They are present in the cells of all green plants and abundant in the leaf mesophyll cells. They are elliptical or oval in shape.

Chloroplast is bounded by two membranes with the intermembrane space called peri plastidial space, containing peri plastidial fluid. It is made up of H2O, mineral ions, proteins, etc. It is a lubricating fluid that avoids friction between the two membranes. The inner chamber is filled with a colorless proteinaceous fluid matrix called the stroma. Besides abundant proteins, stroma contains 70s ribosomes, circular DNA, and all the enzymes of the Calvin cycle.

Embedded in the stroma, there are green-colored bodies called grana which are inter-connected by frets. Grana is the site of light reaction, each granum consists of a stack of lipoprotein membrane discs called Thylakoids. Each thylakoid contains several photosynthetic centers called Quantasomes. Each quantasome contains about 250 chlorophyll pigments and a few xanthophylls and carotenes.

Only chlorophyll- is capable of harvesting light energy into photosynthesis and hence it is called the primary photosynthetic pigment. All the other pigments, merely absorb light energy and pass it on to chlorophyll, and hence are called accessory photosynthetic pigments.

Note: As chloroplasts contain circular DNA 70s ribosomes and as they go for protein synthesis, they are regarded as semi-autonomous cell organelles.

Question 30.
Write any five differences between Mitosis and Meiosis.

Mitosis Meiosis
(a) Equational division (a) Reductional division
(b) Somatic cell division (b) Reproductive cell division
(c) Two cells are formed (c) Four cells are formed
(d) One-step division (d) Two consecutive divisions occur
(e) Chromosomes align on an equatorial plate and the centromeres divide and the chromatids start moving towards the two opposite poles (e) Homologous chromosomes align on the equatorial plate. Half the number of chromosomes will move to opposite poles without division of centromeres.

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 31.
Explain Joseph-Priestlyls experiments on photosynthesis using a candle and a plant.
1st PUC Biology Previous Year Question Paper March 2016 (South) 1
Priestley’s experiment

(a) Priestly performed an experiment to reveal the essential role of air in the growth of green plants.
(b) Priestly observed that a candle burning in a closed space – a bell jar soon gets extinguished.
(c) Similarly a mouse would soon suffocate in a closed space.
(d) He concluded that a burning candle or an animal that breathes the air somehow damages the air.
(e) But when he placed a mint plant in the same bell jar he found that the mouse stayed alive and the candle continued to bum. He concluded that plants restore the air whatever breathing animals and burning candles remove.

Question 32.
Mention any one Hormone secreted by the following glands.
(i) Adrenal gland1
(ii) Thymus gland
(iii) Pineal gland
(iv) Ovary
(v) Testes
(i) Adrenal gland – Adrenaline/noradrenaline
(ii) Thymus gland – Thymosins
(iii) Pineal gland – Melatonin
(iv) Ovary – estrogen .
(v) Testis – Testosterone

Section – II

II. Answer any THREE of the following questions in 200-250 words each, wherever applicable. (3 × 5 = 15)

Question 33.
Mention the function of the following organs.
(i) Forewings of Cockroach
(ii) Crop in the alimentary canal of Cockroach
(iii) Lyphlosole in the alimentary canal of Earthworm
(iv) Setae in Earthworm
(v) Spiracles of Cockroach.
(i) Protecting and covering hindwings
(ii) Storage of food
(iii) Increase the area of absorption
(iv) Locomotion
(v) Exchange of gases

Question 34.
Describe the structure of the stomatal apparatus in Dicot plants.
1st PUC Biology Previous Year Question Paper March 2016 (South) 7
Dicot stomatal apparatus includes,
(a) Stoma: a minute opening present between the guard cells.
(b) Guard cells: Specialised epidermal cells surrounding the stoma. These are two in number and are kidney-shaped. Their outer walls are thin and elastic but inner walls are thick and less elastic.

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 35.
Schematically represent the Nitrogen cycle and explain.
Nitrogen Cycle:

  • Nitrogen is a limiting nutrient for both natural, and agricultural ecosystems.
  • It exists as two nitrogen atoms held together by strong triple covalent bonds (N = N).
  • The nitrogen cycle involves the following steps:
    1. Nitrogen fixation
    2. Ammonification
    3. Nitrification and
    4. Denitrification.

1. Nitrogen Fixation:

  • The process of conversion of nitrogen into ammonia and) or other nitrogen compounds, is known as nitrogen fixation.
  • In nature, lighting and ultraviolet radiation provide energy, to convert nitrogen into nitrogen compounds like N2O, NO, and NO2.
  • The atmosphere also gets some amount of nitrogen oxides from forest fires, automobile exhausts, industrial combustion, and power generating stations.

2. Ammonification:

  • The process by which organic nitrogenous compounds arc decomposed to produce ammonia is known as ammonification.
  • Some ammonia volatilizes and re-enters the atmosphere.
  • Most of the ammonia is converted into nitrites and nitrates.

1st PUC Biology Previous Year Question Paper March 2016 (South) 8
3. Nitrification:

  • Nitrification is the process of converting ammonia first into nitrite, and then into nitrate.
    2NH3 + 3O2 → 2NO2 + 2H + 2H2O
    2NO2 + O2 → 2NO3
  • These processes are carried out by soil bacteria that are chemoautotrophs.
  • Ammonia is oxidized into nitrite by Nitrosomonas and N enterococcus.
  • Nitrite is oxidized to nitrate by Nitrobacter,
  • The nitrates are absorbed by the plants. and reduced to nitrites.
  • The nitrites are transported to the leaves and reduced to ammonia, which forms the amino group of amino acids.

4. Denitrification :

  • It is the process of conversion or reduction of nitrates into free nitrogen.
  • It ¡s carried out by bacteria like Pseudomonas and Thiobacillus.

KSEEB Solutions 1st PUC Biology Previous Year Question Paper March 2016 (South)

Question 36.
(a) Name the formed elements of Blood.
Erythrocytes, Leucocytes, Thrombocytes

(b) Write a note on Erythroblastosis fetal.
This disease is due to the incompatibility of Rh+ve, and Rh-ve blood which may result in the death of the child before or soon after birth. This problem arises when an Rh-ve woman marries a Rh+ve man and bears a Rh+ve fetus. Sometimes due to some placental defect, some of the fetal RBC carrying Rh antigens may pass into the mother’s bloodstream, and cause the production of anti-Rh antibodies. The concentration of anti-Rh antibodies is gradually built up in the mother, and she becomes sensitized for anti-Rh antibodies. There is no risk in the first pregnancy because enough antibodies are not found to destroy the fetus.

In the second or subsequent pregnancies involving a Rh+ve child, these anti-Rh antibodies may return to the fetus through the placenta and destroy the Rh antigen carrying RBC of the fetus and is referred to as Haemolysis. This condition is called the hemolytic disease of newborns (HDN), and the condition is identified as erythroblastosis fetal. The disease tends to become worse in each subsequent pregnancy.

Question 37.
Draw a neat labeled diagram of the sagittal section of the Human Brain.
1st PUC Biology Previous Year Question Paper March 2016 (South) 9