Students can Download 1st PUC Biology Previous Year Question Paper March 2016 (North), Karnataka 1st PUC Biology Model Question Papers with Answers helps you to revise the complete Karnataka State Board Syllabus and score more marks in your examinations.

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

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.
Name the famous botanical garden of England.
Kew Botanical garden.

Question 2.
What is gamopetalous corolla?
If petals are united it is known as gamopetalous corolla.

Question 3.
Name the site of production of blood cells.
Bone marrow.

Question 4.
Mitochondria are called powerhouses of a cell. Give reason.
They produce cellular energy in the form of ATP, hence they are called ‘power houses’.

Question 5.
Name the most abundant animal protein in the world.

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

Question 6.
What are Porins?
Porins are proteins that form huge pores in the outer membranes of the plastids, mitochondria and some bacteria allowing molecules up to the size of small proteins to pass through.

Question 7.
What is chlorosis?
Chlorosis is the loss of chlorophyll leading to yellowing in leaves.

Question 8.
Mention the main cause for ‘Gout’ disease.
Accumulation of uric acid crystals.

Question 9.
Which part of the ovary secretes progesterone.
Corpus luteum.

Question 10.
What are metacentric chromosomes?
The chromosome which has the middle centromere forming two equal arms of the chromosome is a metacentric chromosome.


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

Question 11.
What are Plasmogamy and Karyogamy?

  • The fusion of protoplasms between two motile or non-motile gametes is plasmogamy.
  • The fusion of two nuclei is called karyogamy.

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

Question 12.
State any two universal rules of binomial nomenclature.
(a) Biological names are generally in Latin and written in italics. They are Latinised or derived from Latin irrespective of their origin.
(b) The first word in a biological name represents the genus while the second component denotes the specific epithet.

Question 13.
Distinguish between microsporophyll and megasporophyll of gymnosperms.
Microsporangia bearing sporophylls are known as microsporophylls and megasporangia bearing sporophylls are known as megasporophylls.

Question 14.
What are pseudocoelomates? Give an example.
In some animals, the body cavity is not lined by mesoderm, instead, the mesoderm is present as scattered pouches in between ectoderm and endoderm.

The animals possessing them are called pseudocoelomates.
e.g. Aschelminthes.

Question 15.
Mention any four functions of the plasma membrane.

  1. Cell membrane s a selectively perméable membrane so that, it permits water and other selected materials to get in or out.
  2. It helps in Pinocytosis.
  3. It helps in Phagocytosis.
  4. It helps in the absorption of ions and molecules. (Active transport).

Question 16.
Define glycolysis. Mention any two intermediate 3 carbon compounds produced during glycolysis.
Partial oxidation of glucose to form two molecules of pyruvic acid is referred to as glycolysis. 3-phosphoglyceric acid and phosphoenolpyruvic acid.

Question 17.
Removal of shoot tips, make the hedge in tea plantations. Give reasons.
In most higher plants, the growing apical bud inhibits the growth of the lateral (auxiliary) buds, a phenomenon called apical dominance. Removal of shoot tips (decapitation) usually results in the growth of lateral buds, thus it is widely applied in tea plantations for hedge making.

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

Question 18.
Mention four functional properties of muscle tissue.
(a) Each muscle is made of many long, cylindrical fibres arranged in parallel arrays.
(b) Fibres are composed of numerous fine fibrils called myofibrils.
(c) Muscle fibres contract (shorten) in response to stimulation, then relax (lengthen) and return to their uncontracted state.
(d) Their action moves the body to adjust to the changes in the environment and to maintain the positions of the various parts of the body.


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

Question 19.
Describe the Diplontic life cycle pattern of the plant kingdom.
1st PUC Biology Previous Year Question Paper March 2016 (North) 1
Diplontic life cycle

  • The dominant phase in the life cycle is the independent sporophytic plant.
  • Meiosis occurs in the spore mother cells during spore formation and the gametophyte is short- and is, dependent on the sporophyte.
    e.g. Fucus (brown alga), gymnosperms and angiosperms.

Question 20.
Classify the flowers based on the position of the thalamus giving an example each.
(a) Hypogynous flower – gynoecium occupies the highest position while the other parts are situated below it. Eg. mustard, brinjal.
(b) Perigynous flower – gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level, e.g. plum rose.
(c) Epigynous flowers – margin of the thalamus grows upward enclosing the ovary completely and getting fused with it, the other parts of flower arise above the ovary. Eg. guava and cucumber.

Question 21.
Explain the steps involved in the catalytic cycle of enzyme action.
(a) First the substrate binds to the active site of the enzyme-fitting into the active site.
(b) The binding of the substrate induces the enzyme to alter its shape, fitting more tightly around the substrate.
(c) The active site of the enzyme, now in close proximity of the substrate breaks the chemical bonds of the substrate and the new enzyme-product complex is formed.
(d) The enzyme releases the products of the reaction and the free enzyme is ready to bind to another molecule of the substrate and run through the catalytic cycle again.

Question 22.
What is fermentation? Name any two enzymes involved in this process.
k can be defined as a process of incomplete breaking down of food molecules into Ethyl alcohol, CO2 and lactic acid by the activity of microorganisms or enzymes in the absence of molecular oxygen;

The equation for alcoholic fermentation is
1st PUC Biology Previous Year Question Paper March 2016 (North) 2
Pyruvic acid decarboxylase and alcohol dehydrogenase.

Question 23.
List out any three physiological roles of Gibberellins in plant growth.

  • Discovered by Kurasawa in paddy seedlings, while investigating the cause for Bakane disease.
  • Yabuta, and Suzuki isolated gibberellins from the fungi Gibberellafuzikor
  • Gibberellins break genetic dwarfism in dwarf varieties of pea and beans.
  • Can induce internode elongation and early flowering in rosette plants like cabbage and cauliflower. This is called bolting.
  • Can break seed dormancy and bud dormancy.
  • Can induce parthenocarpic fruits.
  • Gibberellins can substitute cold treatment i.e., can replace vernalisation.
  • Can be used ¡n inducing flowers even in off-seasons in long-day plants.

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

Question 24.
Mention the importance of the following with reference to the Human Digestive System,
(i) Epiglottis
(ii) Villi
(iii) Saliva
(i) Epiglottis prevents the entry of food into the glottis.
(ii) Villi produce microvilli and increase the surface area for absorption of nutrients.
(iii) Saliva helps in lubricating and adhering to the masticated food particles
Salivary amylase helps in the breakdown of starch.

Question 25.
Describe the mechanism of gaseous exchange in alveolus and pulmonary capillary.
1st PUC Biology Previous Year Question Paper March 2016 (North) 3
External respiration:
The exchange of gases takes place between the alveoli of the lungs and the blood is known as ‘External respiration’. It takes place mainly by the process of diffusion. The air pressures are expressed as partial pressure. The partial pressure of O2 is represented as P and the partial pressure of CO2 is PO2. The diffusion takes place from the region of their higher partial pressure to the region of their lower partial pressure.

The exchange of O2 and CO2 between the alveoli and blood can be expressed as follows. The alveoli of the lungs contain 107 mm of Hg of oxygen and the blood contains 45 mm of Hg of oxygen. Hence due to more partial pressure of O2 in the alveoli, O2 diffuses into the blood.

Meanwhile, CO2 diffuses in the opposite direction. The P of the blood capillaries is around 46mm of Hg. White the oxygenated blood capillaries are around 46mm of Hg. While the oxygenated blood has a P of about 36 mm of Hg. Therefore CO2 diffuses from blood capillaries to alveoli.

This can be schematically represented as follows.
1st PUC Biology Previous Year Question Paper March 2016 (North) 4

Question 26.
Name any three excretory structures in invertebrates.
Flame cells, Malpighian tubules, metanephridia.

Part-D (Section – I).

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

Question 27.
List out any five salient features of phylum Echinodermata.

  1. They are exclusively marine.
  2. Echinoderms are rounded, cylindrical or star-shaped organisms.
  3. The body is triploblastic, acoelomate, and unsegmented with radial symmetry. (But larvae are bilaterally symmetrical).
  4. The body is generally covered by skin or exoskeleton supported by an endoskeleton made, up of calcareous plates/ossicles. From these plates, spines may arise which project through the epidermis (skin).
  5. The Head is absent, and the body is distinguishable into oral, and aboral surfaces.
  6. The coelom is extensive, enterococcus filled with coelomic fluid, and amoebocytes.

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

Question 28.
Draw a neat labelled diagram of T.S. of Dicot Root.
1st PUC Biology Previous Year Question Paper March 2016 (North) 5

Question 29.
Describe the structure of the nucleus with a neat labelled diagram.
1st PUC Biology Previous Year Question Paper March 2016 (North) 6
The nucleus is a dynamic celt organelle that actively and randomly controls the functioning of all other cell organelles either electrochemically or neurochemically. The shape of the nucleus varies in different cells. Normally it is spherical, but it may be oval, discoid, kidney-shaped or lobed. The size of the nucleus is also variable. Generally, there is a single nucleus ¡na cell, but some cells also contain two or more nuclei.

The nucleus is composed of the following components:
(a) Nuclear membrane: The nucleus is bounded by a doublç layered nuclear membrane with pores at intervals. The space between the two membranes is known as the per nuclear space.

(b) Nucleoplasm: Within the boundary of the nuclear membrane, a specialized cytoplasm is presently known as nucleoplasm or karyoplasm, which forms the matrix. Bathed in the nucleoplasm are present the nucleolus and chromosomes.

(c) Nucleolus: The nucleolus is a spherical dark body, seen in contact with a specific chromosome at a point called nucleolar organizer. The peripheral portion of the nucleolus is amorphous and contains RNA. The central portion is crystalline and contains DNA. It controls the activities of nucLeus and other cell organdies and is thus regarded as the ‘Nucleus of the nucleus’.

(d) Chromosomes: Chromosomes are the thread-like coloured bodies that are in the intranuclear position which act as the vehicles of heredity and variations. They are self-replicating and exhibit cyclic change ¡n size and shape. They are visible during cell division: Waldeyer described them in 1888.

Chromosomes are the self-reproducing components of the nucleus with DNA, which become visible during cell division. They exhibit a cyclic changes in size & shape.

Question 30.
Describe the events in phases of the cell cycle.
Cell cycle:
The sequence of events that occur between the formation of a cell and its division into daughter cells, is called a cell cycle. It consists of two stages, non-living, growing interphase or interphase and a short dividing mitotic or M – phase.
1. Interphase (L Inter -between, Br. Phasis – aspect). The period between two mitotic divisions is called interphase.

  • G1 Phase: It is the postmitotic phase and takes place at the end of cell division. During this, the active synthesis of RNA and protein takes place.
  • S phase: It is the synthesis phase. During this phase, duplication of DNA and centriole take place.
  • G2 Phase: It is the premitotic gap phase. The synthesis of RNA and protein continues in this phase.

2. Mitotic division: Mitotic division has two processes occurring simultaneously.
They are
(A) Karyokinesis and
(B) Cytokinesis.

A. Karyokinesis: (Or: Karyon-nucleus; kinesis-movement): It is a continuous process and for convenience divided into four stages. They are prophase, metaphase, anaphase and telophase.

B. Cytokinesis: (Gr:kytes-hollow; kinesis-movement): The division of the cytoplasm is called cytokinesis. A furrow develops in the middle of the cell. They deepen centripetally, till the cytoplasm is divided into two equal parts. It forms two daughter cells.

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

Question 31.
Explain the major events of cyclic photophosphorylation in photosynthesis.
Cyclic Photophosphorylation:

  1. It is a cyclic path of electrons expelled from chlorophyll through a series of substrates that are arranged in a suitable oxidation-reduction potential. The energy in the electrons is used for the phosphorylation of ADP to ATP.
  2. In PS I the absorbed photons of light excite chlorophyll-a 700 to eject energised electrons on makes it positively charged and unstable. Electrons pass through the sequence → FRS → FD → Cyt b6 → Cytf → PC and generate ATP at two places. Finally, an electron from PC returns to chi-a restoring its stability.

1st PUC Biology Previous Year Question Paper March 2016 (North) 7

Question 32.
Name any five hormones secreted by the pituitary gland.
(b) Luteinizing hormone
(c) Prolactin
(d) Oxytocin
(e) Vasopressin

Section – II

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

Question 33.
Explain the structure of areolar connective tissue with a labelled diagram.
Areolar tissue:
(a) it is present beneath the skin and in between the muscle fibres.
(b) Areolar tissue is made up of three major components.

  1. Matrix.
  2. Cells.
  3. Fibres.

1. Matriz: It is a homogenous and transparent substance. It is also known as a ground substance. It contains five types of cells and two types of fibres.

2. Cell types :
(a) Fibroblasts or Fibrocytes: These are large and elongated cells with branched ends. They have an oval nucleus and granular cytoplasm. They secrete white and yellow fibres.

(b) Macrophages: These are large cells that move about. They swallow (ingest) foreign bodies like bacteria, thus provide on serving as a defence mechanism.

(c) Mast cells: These are spherical or oval-shaped cells with a spherical nucleus and cytoplasm. They secrete anticoagulatory substances like heparin. They also secrete histamine and serotonin.

(d) Adipose cells or Adipocytes: They are spherical cells and contain a large number of lipids.

(e) Plasma cells: They are oval-shaped cells with agranular cytoplasm and a small nucleus. They produce antibodies.
1st PUC Biology Previous Year Question Paper March 2016 (North) 8
3. Fibres:
(a) White fibres: They are also called collagen fibres. as they are made up of collagen. They are tough and provide strength.
(b) Yellow fibres: They are also called elastin fibres as they are made up of elastin. They are branched and provide elasticity.

Question 34.
Comment on the following:
(i) Symplastic pathway
The symplastic pathway is the movement of water from one cell to another through their cytoplasm and intercellular movement through the plasmodesmata.

(ii) Guttation
The loss of water in liquid form through specialized structures called water stomata or hydathodes is called guttation.

(iii) Plasmolysis
Plasmolysis is the phenomenon of cell shrinkage when the cell is placed in a hypertonic solution.

(iv) Transpiration
It is the phenomenon by which excess water is eliminated, in the form of vapours through the aerial parts of the plant body.

(v) Osmosis
It is a special type of diffusion in which only the solvent or water molecules move from a region of their higher concentration to a region of their lower concentration through a semi-permeable membrane.

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

Question 35.
Describe the process of nodule formation in soybean with diagrams.

  • When the root hair of a leguminous plant comes in contact with Rhizobium, it becomes curled or deformed due to the chemicals secreted by the bacterium.
  • The rhizobia enter these deformed root hair and proliferate within the root hair.

1st PUC Biology Previous Year Question Paper March 2016 (North) 9
Root Nodule Formation in a leguminous plant.

  • The plant responds by forming an infection thread, that grows inwards to deliver the bacteria to the tissues.
  • It is believed that the cytokinin is produced by the bacteria, and the auxin is produced by the plant.
    Cells stimulate cell division, and enlargement to form a nodule.
  • The nodule establishes contact with the vascular tissues of the host for absorption of nutrients.
  • The formation of root nodules and nitrogen fixation occurs under the control of nod genes of legumes, and the nod, if, and fix genes of bacteria.

Question 36.
Describe the structure of the human heart.
1st PUC Biology Previous Year Question Paper March 2016 (North) 10
(a) Heart chambers: The human heart is typically four-chambered. The upper chambers are called uncles or atria The lower chambers are called ventricles. The walls of the auricles are thin, whereas the walls of the ventricles are thick. The auricles are separated by inter auricular septum. Ventricles are separated by the interventricular septum, whereas the auricles and ventricles are separated by the auricula ventricular septum.

(b) Blood vessels associated with the heart: Two large veins called superior vena cava and inferior vena cava come together and form sinus venous. This in turn opens into the right atrium. Two pairs of pulmonary veins (a pair from each lung) open separately into the left atrium from the lungs.

The pulmonary artery arises from the right ventricle and divides into two branches just above the heart. The largest artery called the aorta arises from the left ventricle and runs upward-turns to the left and runs posteriorly as the dorsal aorta.

(c) Valves of the heart: Various types of valves are present at various openings to check the backward flow of blood. The left atrioventricular opening is guarded by two flap-like structures called the bicuspid valves. The free edges (cusps) of these valves are attached to the walls of the ventricles by” Chordae tend Mae”. The opening of the pulmonary artery into the right ventricle and the opening of the aorta into the left ventricle are guarded by semilunar valves.

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

Question 37.
Draw a neat labelled diagram of a neuron.
1st PUC Biology Previous Year Question Paper March 2016 (North) 11