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KA/X/Bio/Pre-Board/2024 Subject: Biology KRISHNAGAR ACADEMY Pre-Board Examination 2024-25 Class-X Maximum Marks. : 80 Maximum Mark 80 Time allowed: Two Hours Answers to this paper must be written on the paper provided separately. You will not be allowed to write during first 15 minutes. This time is to be spent in reading the question paper. This time given at the head of this paper is the time allowed for writing the answers. ------------------------------------------------------------------------------Section A is compulsory. Attempt any four questions from Section B. The intended marks for questions or parts of questions are given in brackets []. --------------------------------------------------------------------------------SECTION-A (Attempt all questions from this Section) Question No. 1. Choose the correct answer :(15x1) i) Which of the following processes requires the involvement of energy? a) Diffusion b) Osmosis c) Passive transport d) Active transport ii) A highly thick muscular chamber of the heart is : a) Right Atrium b) Left Ventricle c) Right Ventricle d) Left Auricle iii) Assertion (A) : Opening and closing of stomata is based on potassium ion exchange theory. Reason (R) : Opening and closing of stomata depends upon turgidity and flaccidity of guard cells. a) Both A and R are True b) Both A and R are False c) A is True and R is False d) A is False and R is True iv) When the level of thyroxine concentration exceeds the normal level in blood then it : a) Inhibits the secretion of TRH by anterior pituitary gland. b) Inhibits the secretion of TSH from the hypothalamus. c) Inhibits the secretion of TRH by hypothalamus. d) Stimulate the secretion of FSH from pituitary gland. v) Prakash is a middle aged man. Since few days he is feeling increased thirst and hunger, gets fatigue easily and has frequent urination. He also observed a lot of ants gathering in the washroom. This is due to : a) Diabetes mellitus b) Kidney failure c) Diabetes insipidus d) None of the above vi) This/these substance(s) cannot pass through semipermeable walls of glomerulus : a) Globin b) Albumin c) Blood cells d) All of these vii) The condition in which a pair of choromosome carry dissimilar alleles is called : a) Homozygous b) Heterozygous c) Phenotypic d) Genotypic viii) All the given sentences are true for vitreous humour except : a) It reflects light b) Keep the shape of the eyeball c) Protect the retina d) Both (b) and (c) Page 1 of 4 KA/X/Bio/Pre-Board/2024 ix)Which of the following is responsible for guttation? a) Suction pressure b) Root pressure c) Osmotic pressure d) Turgor pressure x) As compared to children, population of cells in adults remains constant. Which of the following reasons support this statement? P) In children, new cells are being continuously produced. Q) In adults number of cells produced equals the number of cells dying. R) In children, the number of new cells produced runs short of those that are dying. a) Only P b) Only Q xi)The tail of the sperm helps in : a) Gene b) Motility c) Only P and Q d) Only P and R c) Chromosomes d) Food xii) Water absorption through roots can be increased by keeping the potted plants under the fan. Which of the following reasons support his statement? P) Rate of transpiration increases with the speed of the wind. Q) Rate of transpiration increased in shade. R) As the water is lost from leaf surface by transpiration more water molecules are pulled up. a) Only P b) Only Q c) Only P and R d) Only P and Q xiii) Hari is fond of travelling. He went to desert with family for vacations. He observed that the plants and vegetation in desert is very different form his native place (tropical region). Leaves are modified to spines. This was due to : a) Reduce transpiration b) Excess humidity c) Excess rainfall d) Abundance of water xiv) Prerna was drying clothes on the terrace. Suddenly a monkey came near her. She ran with full speed. Which of the following is/are involved in the process mentioned above? 1. Adrenaline 2. Non-adrenaline 3. Insulin 4. Glucagon a) Only 3 b) Only 1 c) Only 1 and 3 d) Only 2, 3 and 4 xv) Burning of waste substances usually at high temperature is called: a) Land filling b) Composting c) Incineration d) None of these Question No. 2. i) Name the following :(5x1) a) Organ in human concerned with maintaining water balance in the body. b) Pouch like structure of pigmented skin arising from the lower abdominal wall. c) A vein that starts with capillaries and ends in capillaries. d) The period of intra-uterine development of embryo. e) Thinnest blood vessel. ii) Arrange & re-write the terms in logical sequence, beginning with the term that is underlined :(5x1) a) Ovulatory phase, Luteal phase, Follicular phase, Menstrual phase b) Oval window, Ear ossicles, Round window, Eustachian tube c) Islets of Langerhans, Glucagon, -cells, Pancreas, Glycogenolysis d) Diencephalon, Cerebellum, Medulla oblongata, Pons, Cerebrum, Midbrain e) Root hair, Endodermis, Xylem, Cortical cells iii) Fill in the blanks :(5x1) Insufficient secretion of insulin causes (a) . . The word (b) .. means honey referring to the passage of (c) . in (d) .. . A diabetic Page 2 of 4 KA/X/Bio/Pre-Board/2024 person feels (e) urination. because of the loss of water through too much iv) Choose the odd one out :a) Plastics, Glass, Paper, Styrofoam b) Cerebellum, Pons, Arachnoid, Medulla oblongata c) Round, Purple, Inflated, Terminal d) Axon, Cyton, Photon, Dendron e) Salivary gland, Gastric gland, Tear gland, Thyroid gland. (5x1) v) Match the items given in Column I with the most appropriate ones in Columns II and rewrite the correct matching pairs :(5x1) (a) (b) (c) (d) (e) Column I Column II Spinal cord 1. Adrenaline Adrenal medulla 2. 44 Number of autosomes in man 3. Nephrons Kidney 4. 46 Adrenal Cortex 5. Thyroxine 6. Neurons 7. Cortisol Section-B (Attempt any four questions from this section) Question No. 3 a) A woman with blonde curly hair married a man with black soft hair. The gene for black soft hair is dominant over the gene for blonde curly hair. What will be the type of hairs of the children? (1) b) What is the significance of Rh-factor in pregnancy? (2) c) Differentiate between phototropism and geotropism. (2) d) Comment on macula and crista. (2) e) Draw a flowchart explaining the mechanism of blood clotting. (3) Question No. 4 a) What is the scientific name for man? b) What are the vestigial organs? Give one example. c) Mention one function each for Cerebrum and Cerebellum. d) Mention any two features of the Cro-Magnon man. e) Study the picture given below and answer the questions that follow. (i) Name the category of waste that is being disposed. (ii) Give an example of such a waste. (iii) Are they hazardous to humans and animals? Give a suitable reason to justify your answer. (1) (2) (2) (2) (3) Question No. 5 a) What is the scientific name for first man-like ancestor? (1) b) What is pure strain and how is it different from a hybrid strain? (2) c) State two functions of glucagon. (2) d) Differentiate between endocrine gland and exocrine gland. (2) e) The figure given below represents an experimental setup to study a physiological process in plants. Study the figure and answer the questions that follow. (3) Page 3 of 4 KA/X/Bio/Pre-Board/2024 (i) (ii) (iii) What is the aim of the experiment? Identify A, B, C and D What would happen to the rate of photosynthesis if a pinch of sodium bicarbonate is added to the water in the beaker? Question No. 6 a) Mention two types of IUDs. (1) b) Differentiate between the theories of Lamarck and Darwin. (2) c) Some women have facial hair like beard and moustache. Give suitable reason. (2) d) What is the significance of meiosis? (2) e) Study the given diagram of male reproductive system and answer the questions that follow. (3) (i) Identify the structure labelled A . (ii) How does part F differs from part D ? (iii) Among A, B and C where are seminiferous tubules located? Question No. 7 a) Define smog. (1) b) The leaves of a potted plant were coated with Vaseline. What will be your observation after few days? (2) c) State the functions of aqueous humor and vitreous humor. (2) d) All variations in a species do not have equal chances of survival. Explain. (2) e) A complete ring of bark was removed from a tree as shown in the figure A . After about one month, the bark of the tree appeared as B . Study the figures and answer the questions that follow. (3) (i) What is the aim of the above experiment? (ii) Why does the bark below the ring shrink? (iii) Why does the bark above the ring swell up? Question No. 8 a) b) c) d) Explain the abbreviation MTP. Where does the pericardial fluid found? What is its function? Why does one feel blinded for some time, while coming out of the dark? What are the differences between diabetes insipidus and mellitus? e) Observe the diagram given below and answer the following i. Identify the eye defect. ii. What is the function of B ? iii. Give two possible reasons for this eye defect. (1) (2) (2) (2) (3) Page 4 of 4
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