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SECOND PRE BOARD EXAMINATION JANUARY 2016 Class: X Time: 2Hrs Subject: BIOLOGY Max Marks: 80 ______________________________________________________________________________________ Attempt all the questions from Section I and any four questions from Section II . The intended marks for questions or parts of questions are given in brackets ( ). SECTION I (40 MARKS) (Attempt all questions from this Section) Question 1 (a) Name the following: (5) i. ii. iii. iv. The folds of inner wall / layer in mitochondria. The light rays absorbed from the visible spectrum by the chlorophyll for photosynthesis. The vaccine given to babies that helps build immunity against three diseases. Artificially introducing weakened germs or germ substances into the body for developing resistance to a particular disease. v. The mineral element required by plants in the formation of chlorophyll. (b) State whether the following statements are true or false. If false, write the correct form of the statement by changing the underlined words only. (5) i. ii. iii. iv. v. The thyroid gland is both exocrine and endocrine in function. Mortality is the number of deaths per thousand of the population per decade. The process of fusion of the sperm nucleus and the egg nucleus is termed implantation. Rods are responsible for vision in the light. Dilation of the pupil is brought about by the sympathetic nervous system. (c) The following paragraph is related to transpiration by plants. Copy and complete the following paragraph by selecting the correct word from those given in the box. You may use the term only once. (5) Cuticle, stoma, lesser, greater, close, open and lenticels Stomatal transpiration is controlled by the plants by adjusting the size of the ___1______, whereas this does not happen in the case of cuticular and lenticular transpiration. _____2_____ is a waxy layer secreted by the epidermis on the two surfaces of the leaf. The ___3______ the thickness of the cuticle, the _____4______ is the evaporation (transpiration). ______5_____ are special openings that develop on the older stem in place of stomata. Lenticels never ____6_____. They remain ______7___ all the time. (d) Name the fluid that: i. ii. iii. iv. v. (5) Protects and nourishes the brain. Filters out into the Bowman s capsule under pressure. Protects the developing embryo. Kills the germs in the eyes. Helps to transport hormones. (e) Mention the location of the following structures and give their respective functions (if any): (10) i. ii. iii. iv. v. Node of Ranvier. Ciliary muscles. Epididymis. Palisade mesophyll cells. Hydathodes. 1 (f) Match the items in column A with those in column B . Rewrite the correct matching pair. (5) Column A SA node Lymph Defective haemoglobin in RBC Cardiac cycle Lymphocytes (i) (ii) (iii) (iv) (v) Column B 0.85 sec antibodies pacemaker has leucocytes Sickle cell anaemia 0.95 sec has erythrocytes (g) Name the organs/tissues/location in which the following process takes place: i. ii. iii. iv. v. (5) The ultra filtration of the blood to remove nitrogenous waste. The production of gametes or sex cells. Positive feed back mechanism in the control of hormonal secretions. The watery liquid in the eye which keeps the lens moist and refracts light. The deposition of extra glucose in blood as glycogen. SECTION II (40 Marks) Attempt any four questions from this Section. Question 2 a) Observe the diagram beside, a certain stage in mitosis. Study the same and answer the questions that follow: (5) i. Identify the stage and give reasons for your answer. ii. Name the parts labelled 1, 2 and 3. 1 iii. Is it a plant cell or an animal cell? Give a reason for your answer. 2 iv. Explain the process of cytokinesis in the given cell. 3 v. Name and draw a neat labelled diagram of the stage which just comes before the given stage beside. b) Given beside is an apparatus used to study a particular process in plants. Study the same and answer the questions that follow: i. ii. iii. iv. v. vi. (5) Name the apparatus. Mention one limitation of this apparatus. Which phenomenon is studied with the help of this apparatus? What is the function of the part marked reservoir ? What is the role of the air bubble in the experiment? Transpiration is the price paid for photosynthesis . Explain. Question 3 a) Define the following terms: i. Photophosphorylation ii. Tonicity iii. Reflex arc iv. Polymerisation v. Osmoregulation. (5) 2 b) Observe the diagram beside which is an organelle in a cell. Study the same and answer the questions that follow: i. Identify the organelle. Where do you find them? ii. Define the process done by this organelle. iii. Label the parts numbered 1 and 2. iv. Name the processes happening in the parts numbered 1 and 2. (5) Question 4 a) Given beside is the diagram of an experiment set up to demonstrate certain phenomenon in plants. Study the same and answer the questions that follow: i. ii. iii. iv. v. (5) Name and define the physiological process being studied in the experiment. What is the role of oil in the experiment? What do you observe in test tube A and B after some time? Give reasons for your observations. State the purpose of setting up test tube B. b) Differentiate between the following pairs on the basis of what is mentioned within the brackets: (5) i. ii. iii. iv. v. Hypotonic and hypertonic solutions (Type of osmosis occurring) Light intensity and temperature ( Role in photosynthesis) Circulating fluids and Non circulating fluids (Two examples) Carbon dioxide and carbon monoxide (Complex formed with haemoglobin) Vasoconstriction and vasodilation (Colour of the skin) Question 5 (5) a) The diagram given alongside represents certain organ systems in the abdominal region of humans. Study the same and answer the questions that follow. i. ii. iii. iv. Identify the two organ systems shown in the diagram. Name the parts labelled 1 7. What is the function of the parts labelled 1, 3 and 6. Draw a neat labelled diagram of the vertical section of the part labelled 2. b) Give scientific reasons for the following statements: i. ii. iii. iv. v. (5) LUBB and DUP sounds are heard during heart beat. WBCs are the only blood cells which can only exhibit the process of diapedesis. The walls of the left ventricle are thicker than the walls of all other chambers. Only the veins and not the arteries are provided with valves. The blood groups of both the donor and recipient must be known before transfusing. Question 6 a) i. Draw a neat labelled diagram of the structure found in the inner ear. ii. Name the part of the structure that is responsible for the following: 1. Static balance in human beings. 2. Dynamic balance 3. Hearing 4. Tube connecting the middle ear with the throat. 3 b) Given alongside is a part of cross section of a plant root. Study the same and answer the questions that follow: (5) i. Name the parts labelled 1, 2 and 3. ii. Name the two type of conducting tissues present within the layer labelled 2. Give their functions. iii. Draw a neat diagram of the root hair. Is it unicellular or multicellular? iv. Give the technical term for the condition of the root hair if the soil is not watered. Question 7 a) Given the diagram alongside shows the microscopic view of an animal tissue undergoing active (5) mitotic cell division. Observe carefully and answer the questions that follow: i. ii. iii. iv. Identify and name the different stages of mitosis labelled 2 to 5. Give reasons for your answer in (i). Why the stage labelled 1 is called resting phase? What is the other name of resting phase? Mention it three phases. b) The pea plant with green and inflated pods are crossed with pea plant having yellow and constricted pods. All the progeny F1 generation were the plants with green and inflated pods. With the help of this cross, answer the questions that follow: (5) i. Give the genotype of the F1 progeny and its parents. ii. Write the punnett square to show the cross between the off springs of F1 generation when self crossed. iii. Mention the genotype and phenotype ratio of F2 generation. iv. Name and explain the law proposed by Dr. Mendel based on these observations. 4
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