BIOLOGY PAPER - 1. (THEORY) (Botany and Zoology)

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2 BIOLOGY PAPER - 1 (THEORY) (Botany and Zoology) (Three hours) (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.) Answer all questions in Part I and six questions in Part II, choosing two questions from each of the three sections A, B and C. All working including rough work, should be done on the same sheet as, and adjacent to, the rest of the answer. The intended marks for questions or parts of questions are given in brackets [ ]. Question 1 PART I (20 Marks) Answer all questions. Give a brief answer for each of the following: [4] (b) (i) (iii) (iv) What happens if excess fertilizers are added to the soil? Why are the annual rings absent in plants growing along the coastal areas? What is a Punnett-square used for? Malignant tumours are considered dangerous. Why? Each of the following statements/ questions has four suggested answers. Choose the correct option in each case: 1. Gene therapy can be used to correct one of the following: (i) (iii) (iv) SCID HIV Typhoid Hepatitis [4] ISC SAMPLE QUESTION PAPER 2015

3 2. The dark coloured dead wood present in the central region of old trees is called: (i) Spring wood Sap wood (iii) Duramen (iv) Alburnum 3. Which of the following statements is correct? (i) Surgical methods of contraception do not prevent gamete formation. In E.T. techniques, embryos are always transferred into the uterus. (iii) Oral pills are very popular contraceptives among the rural women. (iv) All STDs are not completely curable. 4. The Hardy Weinberg s equilibrium is associated with: (i) Ionic equilibrium. Population genetics. (iii) Osmotic balance. (iv) None of these. (c) Give a scientific term for each of the following: [4] (i) Development of fruit without fertilization. The process of mrna synthesis on a DNA template. (iii) A plant part excised from its original location and used for initiating a culture. (iv) The surgical removal of a section of vas deferens. (d) Expand the following abbreviations: [4] (i) PKU GIFT (iii) DNA (iv) GMO (e) Name the scientists who have contributed to the following: [4] (i) Principle of Limiting Factor. The recapitulation theory. (iii) Discovered the fossil of Archaeopteryx. (iv) Described double fertilisation in plants ISC SAMPLE QUESTION PAPER 2015

4 PART II (50 Marks) SECTION A Answer any two questions. Question 2 Describe different types of natural selection with the help of graphs. [3] (b) Give two chromosomal similarities between man and apes. [1] (c) Give two distinguishing features of the Cro-Magnon man. [1] Question 3 Describe how the origin of life from abiotic substances was proved experimentally by Miller and Urey. (b) Give one significant difference between Biogeny and Cognogeny. [1] (c) What is a vestigial organ? Give one example. [1] Question 4 What are the basic postulates of Darwinism? What is the objection against Darwinism? (b) Write two distinctive features of Australopithecus. [1] (c) Question 5 Define atavism. SECTION B Answer any two questions. Draw a well labelled diagram of the L.S. of an anatropous ovule just before fertilization. (b) Write short notes on the following: [4] (c) (i) Endosperm Amniocentesis Give four significant differences between active and passive absorption of water in plants. [3] [3] [1] [4] [2] ISC SAMPLE QUESTION PAPER 2015

5 Question 6 Briefly describe the mechanism of development of a dicot embryo. [4] (b) Give two significant differences between each of the following: [4] (i) Racemose and Cymose inflorescence Self-pollination and Cross pollination (c) Write a brief note on MTP. [2] Question 7 Fertilization in humans is a physio-chemical process. Explain. [4] (b) Give a graphical representation of the C4 cycle. [4] (c) Give the names of foetal membranes in mammals. [2] SECTION C Question 8 Answer any two questions. Describe lac-operon. [4] (b) What are green manures? Why are biofertilisers preferred over chemical fertilisers? [4] (c) Define: (i) Biopiracy Pleiotropy [2] Question 9 Define hybridization. Explain the technique of hybridization in plants. [4] (b) What are the implications of the loss of biodiversity? [4] (c) Give one significant difference between: [2] (i) Hydrophytes and Xerophytes Inbreeding and Outbreeding Question 10 Give four applications of recombinant DNA technology. [4] (b) Write short notes on: [4] (i) Haemophilia Down s Syndrome (c) Explain the process of sex determination in humans. [2] ISC SAMPLE QUESTION PAPER 2015

6 BIOLOGY PAPER - 2 (PRACTICAL) (Three hours) SPECIMEN PAPER I OF II (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.) Answer all questions. All working including rough work should be done on the same sheet as the rest of the answer. The intended marks for questions or parts of questions are given in brackets [ ] Note: Q4 (Spotting) is to be attempted on a separate continuation sheet. The continuation sheet is to be handed over to the Supervising Examiner after the last observation. This continuation sheet should be attached to the main answer booklet of the candidate after the examination. Question 1 [5] (b) (c) (d) Examine carefully the flower specimens D41 and D42 provided. Describe their floral characters in semi-technical terms. (Details of individual whorls are not required). Cut a longitudinal section of the flower specimen D41 with a sharp razor blade. Arrange one of the cut surfaces on a moist filter paper. Draw a neat and labelled diagram of the cut surface. Show the L.S. to the Visiting examiner. With the help of a sharp blade cut a longitudinal section of specimen D42. Arrange one of the cut surfaces on a moist filter paper. Draw a neat and labelled diagram of this cut surface, highlighting the essential whorls. Observe with a hand lens the cut surfaces of D-41 and D-42. Record your observations in the table below: Androecium D41 D42 (i) Relation of stamens to each other Method of attachment of anther to filament Gynoecium (i) Nature of stigma Type of placenta ISC SPECIMEN QUESTION PAPER 2015

7 (e) (f) (g) Name the families to which each flower specimen belongs. Point out any two features, which are distinctive characteristics of each family. Take a fresh specimen of D41. With the help of a forceps, remove the whorls one by one, till you reach the gynoecium. With the help of a sharp razor blade, cut a transverse section of the ovary. Draw a neat and labelled diagram of the transverse section. Show the T.S. to the Visiting examiner. (h) State the floral formulae of specimens D41 and D42. (i) Draw the floral diagram of specimen D42. (j) Mention one economically important plant belonging to each family mentioned in (f) above (Write the botanical name only). Question 2 [5] Procedure: 1. Take a 250ml beaker which has about 2cm of solvent at the bottom. Cover the beaker with aluminium foil to prevent the vapours from spreading. 2. Cut a piece of filter/ chromatography paper which is long enough to reach the solvent. Draw a pencil line about 1.0 cm from the bottom of the paper. 3. Use a coin (quarter) to extract the pigments from the cells of the given leaf. Place a small section of leaf on the top of the pencil line drawn on the paper. Use the ribbed edge of the coin to crush the leaf cells. Be sure the pigment line is on top of the pencil line. Use a back and forth movement exerting firm pressure throughout. 4. Place the filter paper/chromatography paper in the beaker such that the tip of the paper touches the solvent. Do not allow the pigment to touch the solvent. 5. Cover the beaker. When the solvent is about 1 cm from the top of the paper, remove the paper and immediately mark the location of the solvent front before it evaporates. 6. Mark at the bottom of each pigment band. Measure the distance each pigment migrated from the bottom of the pigment origin to the bottom of the separated pigment band. Record the distance moved by each front, including the solvent front, in the table below. Depending on the species of the plant used, you may be able to observe 4 or 5 pigment bands. Distance moved by Pigment Band (millimetres) Band Number Distance moved (mm) Band Colour Distance Moved by the Solvent Front (mm) ISC SPECIMEN QUESTION PAPER 2015

8 Analysis of Results The relationship between the distance moved by a pigment and the distance moved by the solvent is a constant called Rf. It can be calculated for each of the pigments using the formula: Distance pigment migrated (mm) Rf = Distance solvent front migrated (mm) Record your Rf values in the table below: = Rf for carotene (yellow to yellow-orange) = Rf for xanthophyll (yellow) = Rf for chlorophyll a (bright green to blue green) = Rf for chlorophyll b (yellow green to olive green) Answer the following questions: What are the factors involved in the separation of pigments? (b) Would you expect the Rf value of a pigment to be the same if a different solvent was used? Explain. (c) What type of chlorophyll does the reaction centre contain? What are the roles of the other pigments? Question 3 [5] With the help of a sharp razor/blade, cut thin sections of D43. Select a good transverse section and stain it with safranin. Mount the section in glycerine. Show your slide to the Visiting Examiner under a low power microscope. (b) Draw a neat labelled outline of the mount as observed under the microscope. (c) Identify the specimen and mention at least three important characteristics. Question 4 [5] Identify the given specimens A to E. For specimen E identify the type of inflorescence. Give two identifying characteristics to support your answer in each case. Draw a neat labelled diagram of each specimen. You are not allowed to spend more than three minutes for each spot. Note: Hand over your continuation booklets to the Supervising Examiner after you finish answering this question. Question 5 Show the following to the Visiting Examiner for assessment: Project (b) Biology Practical File. [7] [3] ISC SPECIMEN QUESTION PAPER 2015

9 PAPER 2 (PRACTICAL) List of Items for Spotting Spotting: 1. T.S. of monocot root - slide 2. T.S. of testis of mammal - slide 3. Plasmodium - slide 4. Capitulum inflorescence 5. Experiment to show transpiration in a plotted plant covered by a polythene bag ISC SPECIMEN QUESTION PAPER 2015

10 BIOLOGY PAPER - 2 (PRACTICAL) (Three hours) SPECIMEN PAPER II OF II (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.) Answer all questions. All working including rough work should be done on the same sheet as the rest of the answer. The intended marks for questions or parts of questions are given in brackets [ ] Note: Q4 (Spotting) is to be attempted on a separate continuation sheet. The continuation sheet is to be handed over to the Supervising Examiner after the last observation. This continuation sheet should be attached to the main answer booklet of the candidate after the examination. Question 1 [5] (b) (c) (d) Examine carefully the flower specimens D41 and D42 provided. Describe their floral characters in semi-technical terms. (Details of individual whorls are not required). Cut a longitudinal section of the flower specimen D41 with a sharp razor blade. Arrange one of the cut surfaces on a moist filter paper. Draw a neat and labelled diagram of the cut surface. With the help of a sharp blade cut a longitudinal section of specimen D42. Arrange one of the cut surfaces on a moist filter paper. Draw a neat and labelled diagram of this cut surface, highlighting the essential whorls. Observe with a hand lens the cut surfaces of D-41 and D-42. Record your observations in the table below: Androecium D41 D42 (i) Relation of stamens to each other Gynoecium Method of attachment of anther to filament (i) Nature of stigma Type of placenta (e) (f) Name the families to which each flower specimen belongs. Point out any two features, which are distinctive characteristics of each family ISC SPECIMEN QUESTION PAPER 2015

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BIOLOGY. PAPER - 1 (THEORY) (Botany and Zoology)

BIOLOGY. PAPER - 1 (THEORY) (Botany and Zoology) BIOLOGY PAPER - 1 (THEORY) (Botany and Zoology) (Three hours) (Candidates are allowed additional 15 minutes for only reading the paper. They must OT start writing during this time.) ----------------------------------------------------------------------------------------------------------------