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Page 1 of 2 CENTRAL MODERN SCHOOL Half Yearly Examination, Session : 2020 2021 Class X BIOLOGY Time : 2 hrs. (+ 15 mins. RT) F.M. : 80 ( You are advised to write the answers within (1) 8 page booklet and (1) continuation sheet ) SECTION I (40 Marks) (Attempt all questions from this section) [You should not spend more than 1 hour in this section.] Question : 1 a) Name the following : [5] i) Minute openings on woody stems. ii) The pigment causing clear yellow colour of urine. iii) The muscle fibres between AV Node and interventricular septum. iv) The substances having strong affinity for water. v) The force which causes the water to stick to the inner surface of the xylem cells. b) Mention the exact location of : [5] i) Papillary Muscles ii) Hydathodes iii) Pulvinus iv) Pericardial Fluid v) Spleen c) Correct and rewrite the statements by changing the underlined words only : [5] i) Osmosis is multi-directional. ii) Mitosis occurs in testis to produce sperms. iii) Monocytes produce antibodies to neutralise the toxic effect of germs. iv) Oxygen released during photosynthesis is obtained from CO2 . v) DUP sound is produced during closure of atrio-ventricular valves. d) Write down the function of : [5] i) Chordae tendinae ii) Centromere iii) Cuticle iv) Tricuspid valve v) Ureter e) Choose the correct word from the brackets and rewrite the statements : [5] i) The smallest united branch of capillaries is . (arteriole, venule, vein). ii) Urea is produced in (liver, kidney, small intestine). iii) Food is transported in plants in the form of (glucose, starch, glycogen). iv) . (RNA, DNA, RNA & proteins) is mainly synthesized during S-Phase of cell cycle. v) Lymph is ultimately poured into ( Pulmonary vein, Precaval vein, Postcaval vein). f) Identify the odd term and name the category of the remaining terms : [5] i) Adenine; Histone; Guanine; Thymine. ii) Biconcave ; Large nucleus; Haemoglobin; 7micron diameter. iii) Sunlight; Wind Velocity; High Temperature; Humidity. iv) Carbon Dioxide; Urea; Uric Acid; Ammonia. v) Pulmonary Artery; Vena Cava; Tricuspid Valve; Bicuspid Valve. g) Give suitable reasons for the following : [5] i) Osmosis is referred to as passive transport. ii) Blood samples are collected from veins and not from arteries. iii) Meiosis is called as reduction division. iv) Blood pressure is very high in the kidneys. v) Overuse of fertilisers might kill the plants. h) Expand the following : [5] i) ADH ii) NADPH iii) DCT iv) SAN v) RNA SECTION II (40 marks) (Attempt any four questions) [ Do not spend more than 1 hour in this section ] Question : 2 a) i) Draw a diagram to show cytokinesis in plant cells. ii) How does it differ between plant and animal cells ? iii) In which phase of cell division does cytokinesis start ? [5] Contd......Page 2 Page 2 of 2 b) Differentiate between the terms on the basis of instructions given in the brackets : i) Nucleotide and Nucleosome (Components) ii) Hypotonic and Hypertonic Solution ( Condition of a cell placed in it) iii) PCT and Loop of Henle (Location within the kidney) iv) Transpiration and Guttation (Form in which water is lost) v) Systole and Diastole (Condition of heart chambers) [5] Question : 3 a) i) Draw a labelled diagram of the L.S. of kidney,clearly demarcating cortex and medulla. ii) Explain the process of ultrafiltration. iii) Mention the site of ultrafiltration. b) i) Draw a labelled diagram of a part of leaf epidermis showing one single stoma. ii) Explain the mechanism of opening of stoma according to the K+ ion concentration theory. iii) State any two adaptions in plants to reduce transpiration. [5] Question : 4 a) i) Draw the labelled diagram to show the cross sections of arteries and veins. ii) Mention any two structural differences observed from your diagram. iii) Name the types of blood that passes through arteries and veins respectively. b) Give proper biological / technical terms : i) The process of maintaining salt and water balance in the body. ii) The upper layers of mesophyll cells of a leaf. iii) A lymphatic node on the sides of the neck. iv) The pigment obtained due to breakdown of RBC in the liver. v) Form of storage of sugar in animals. [5] Question : 5 a) i) Draw a labelled diagram of a chloroplast. ii) Give the exact location of the pigment present in it. iii) What is the effect of temperature on photosynthesis ? iv) Write down the equation of photosynthesis. b) Explain the following terms : i) Photophosphorylation ii) Pulse iii) Vasodilation iv) Transpiration Pull v) Plasmolysis [5] [5] [5] [5] Question : 6 [5] a) i) Draw a labelled diagram of a single root hair. ii) State the adaptations of root hairs for absorption of water. iii) Give two uses of turgidity in plants. b) Fill in with suitable words to complete the paragraph : [5] The injured tissue cells and platelets release __(i)__ at the site of injury which acts as an enzyme that converts __(ii)__ produced in liver into __(iii)__ in presence of __(iv)__ ions. The fibrin network formed from __(v)__ in the blood plasma traps blood cells and shrinks to form a solid mass called clot. Question : 7 a) A potted plant was kept in the dark for 24 hours and one of its leaf was covered with a black paper in the centre. The plant was then placed in sunlight for a few hours. [5] i) Why was the plant kept in the dark and what aspect of photosynthesis was being tested ? ii) Why was the experimental leaf boiled in water and then in methylated spirit, during starch test ? iii) Draw the experimental leaf after the starch test. b) i) Draw a diagram to represent the process of diapedesis and label any two types of blood cells. [5] ii) Give two special features of the cells performing the above process. iii) What is phagocytosis ? -------- x -------N.B. : Parents are requested to ensure that the gravity, sanctity and above all honesty in the Half Yearly Examinations are maintained by the students.
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