PCMB Paper with Demo Solution Maharashtra Board Class 12th PDF

# H.S.C. Model Question Paper - I ## Physics **Time: 3 Hours** **Total Marks : 70** ### General Instructions : 1. The question paper is divided into four sections. 2. **Section A :** Q.No.1 contains Ten multiple choice type of questions carrying One mark each. Q.No.2 contains Eight very short...

# H.S.C. Model Question Paper - I ## Physics **Time: 3 Hours** **Total Marks : 70** ### General Instructions : 1. The question paper is divided into four sections. 2. **Section A :** Q.No.1 contains Ten multiple choice type of questions carrying One mark each. Q.No.2 contains Eight very short answer type of questions carrying One mark each. 3. **Section B :** Q.No.3 to Q. No. 14 contains Twelve short answer type of questions carrying Two marks each. (Attempt any Eight). 4. **Section C :** Q.No.15 to Q. No. 26 contains Twelve short answer type of questions carrying Three marks each. (Attempt any Eight). 5. **Section D :** Q.No.27 to Q. No. 31 contains Five long answer type of questions carrying Four marks each. (Attempt any Three). 6. Use of log table is allowed. Use of calculator is not allowed. 7. Figures to the right indicate full marks. 8. For each MCQ, correct answer must be written along with its alphabet. e.g., (a).........../(b)............/(c)/(d)........... Only first attempt will be considered for evaluation. 9. Physical constants: - Latent heat of vaporisation, $L_{vap}=2256 kJ/kg$ - Acceleration due to gravity, $g=9.8 m/s²$. ### Section A **Q. 1. Select and write the correct answer:** 1. When the balance point is obtained in the potentiometer, a current is drawn from - (A) both the cells and auxiliary battery - (B) cell only - (C) auxiliary battery only - (D) neither cell nor auxiliary battery 2. The minimum velocity (in $m s^{-1}$) with which a car driver must traverse a flat curve of radius 150 m and coefficient of friction 0.6 to avoid skidding is (g = 10 $m/s²$) - (A) 60 - (B) 30 - (C) 15 - (D) 25 3. A circular coil of 100 turns with a cross-sectional area (A) of 0.5 $m^2$ is kept with its plane perpendicular to the magnetic field (B) of 4 T. What is the magnetic flux linkage with the coil? - (A) 400 Wb - (B) 100 Wb - (C) 50 Wb - (D) 200 Wb 4. In a moving coil galvanometer, we use a radial magnetic field so that the galvanometer scale is - (A) linear - (B) algebraic - (C) logarithmic - (D) exponential 5. The forward voltage drop of an LED is - (A) much larger than the ordinary diode. - (B) much less than that of the ordinary diode. - (C) almost 1.5 to 3.5 volts. - (D) Both (A) and (C) 6. If the incident energy is 200 cal, absorptive power is 0.31 and reflection coefficient is 0.41, then the amount of energy transmitted will be - (A) 48 cal - (B) 56 cal - (C) 58 cal - (D) 54 cal **Q. 2. Answer the following questions:** 1. What are eddy currents? 2. A wave is represented by an equation $y=A sin (Bx-Ct)$. Given that the constants A, B and C are positive, can you tell in which direction the wave is moving? 3. The half life of radium is 1600 years. Find the fraction of a sample of radium that would remain after 6400 years. 4. What will be the direction of angular displacement and angular velocity, if angular acceleration is constant and is along the axis of rotation? 5. In a common-base connection, a certain transistor has an emitter current of 11 mA and collector current of 10.7 mA. Calculate the value of the base current. 6. Define S.I. unit of magnetic field. 7. What will happen to the mean square speed of the molecules of a gas if the temperature of the gas decreases? 8. Define Potential Gradient. ### Section B **Attempt Any Eight :** **Q. 3. ** In SI units, the differential equation of an S.H.M. is $\frac{d^2x}{dt^2}=-16x$. Find its frequency and period. **Q. 4.** Explain relation between electric field and electric potential. **Q. 5.** State the properties of an ideal fluid. **Q. 6.** Calculate molar specific heat of mono-atomic gases at constant volume and constant pressure. **Q. 7.** Find the time required for a 25 Hz alternating current to change its value from zero to the r.m.s. value. **Q. 8.** On what factors, does the frequency of a conical pendulum depend? Is it independent of some factors? **Q. 9.** Two coherent sources whose intensity ratio is 16:9 produce interference fringes. Calculate the ratio of amplitudes of light waves coming from them. **Q. 10.** Derive an expression for the energy stored in a magnetic field. **Q. 11.** State the difficulties faced by Rutherford's atomic model. **Q. 12.** A sound wave in a certain fluid medium is reflected at an obstacle to form a standing wave. The distance between two successive nodes is 4.5 cm. If the velocity of sound is 1629 m/s, find the frequency. **Q. 13.** Explain resultant magnetic moment of an atom with the help of Pauli's exclusion principle. **Q. 14.** The common-base DC current gain of a transistor is 0.982. If the emitter current is 15 mA, what is the value of base current? ### Section C **Attempt Any Eight :** **Q. 15.** A wire of length 0.5 m is stretched by 2 kg wt. If mass of the wire is 0.98 x 10^-3 kg. find the velocity of transverse wave along the wire and its fundamental frequency. **Q. 16.** Calculate the M.I of thin uniform rod of mass 300 g and length 50 cm about an axis perpendicular to its length and passing through - i. its centre and - ii. one end. **Q. 17.** What is series LCR resonant circuit? State conditions for series resonance. Obtain an expression for resonant frequency. **Q. 18.** Derive the relation between surface tension and surface energy per unit area. **Q. 19.** Discuss the maximum and minimum values of displacement, velocity and acceleration of a particle performing linear S.H.M. **Q. 20.** The maximum value of permeability of a metal (77% Ni, 16% Fe, 5% Cu, 2% Cr) is 0.126 T mA¯¹. Find the maximum relative permeability and susceptibility. **Q. 21.** Explain the variation of temperature according to Prevost's theory of heat exchange. **Q. 22.** Explain the Huygens' construction of plane wavefront. **Q. 23.** 2.0 kg of liquid water is boiled at 100 °C and all of it is converted to steam. If the change of state takes place at the atmospheric pressure (1.01 × 10^5 Pa), calculate - i. the change in the internal energy of the system. Given, the volume of 2 kg of water changes - ii. the energy transferred to the system, - iii the work done by the system during this change, and from 2.0 x 10^-3 $m^3$ in liquid form to 3.342 $m^3$ when in the form of steam. **Q. 24.** Define the following terms: - i. Excitation energy of an electron in an atom - ii. Binding energy of an electron in an atom - iii. Dark resistance of a photodiode **Q. 25.** An electric dipole consists of two opposite charges each of magnitude 1 µC separated by 2.5 cm. The dipole is placed in an external electric field of 1.2 × 10^5 NC¯¹. Find: - i. The maximum torque exerted by the field on the dipole - ii. The work the external agent will have to do in turning the dipole through 180° starting from the position 0 = 0° **Q. 26.** State Lenz's law and explain how it is incorporated in Faraday's law. ### Section D **Attempt Any Three: ** **Q. 27.** - i. State and explain Newton's law of viscosity. - ii. Plane wavefront of light of wavelength 6500 Å is incident on two slits in a screen perpendicular to the direction of light rays. If the total separation of 10 bright fringes on a screen 1.5 m away is 3 cm, find the distance between the slits. **Q. 28.** - i. State and explain Kirchhoff's current law in electric circuit. - ii. Figure shows currents in a part of electrical circuit. Find the current X. **Q. 29.** Describe the experimental set-up for a photoelectric effect with the help of neat and labelled schematic diagram. **Q. 30.** - i. Derive the relation for magnetic force acting on an arbitrarily shaped wire assuming relation for a straight wire. - ii. A straight conductor 1 m long carrying a current of 12 A is kept at right angles to a uniform magnetic field of induction 5.5 × 10^-3 Wb/m². What is the force acting upon it? **Q. 31.** With the help of p-V diagram explain the work done by the system while expanding when - i. System undergoes first volume change at constant pressure and then the pressure changes at constant volume. - ii. System undergoes first pressure change at constant volume and then the volume change at constant pressure. - iii. In which case will the work done be more? ## Chemistry **Time : 3 Hours** **Total Marks : 70** ### General Instructions: 1. The question paper is divided into four sections. 2. **Section A:** Q.No.1 contains Ten multiple choice type of questions carrying One mark each. Q.No.2 contains Eight very short answer type of questions carrying One mark each. 3. **Section B:** Q.No.3 to Q. No. 14 contains Twelve short answer type of questions carrying Two marks each 4. **Section C:** Q.No.15 to Q. No. 26 contains Twelve short answer type of questions carrying Three marks each. 5. **Section D:** Q.No. 27 to Q. No. 31 contains Five long answer type of questions canying Four marks each 6. Use of log table is allowed. Use of calculator is not allowed. 7. Figures to the right indicate full marks. 8. Answers to the questions of section A, B, C and D should be written in the same answer book. 9. For each MCQ, correct answer must be written along with its alphabet. F. g. (a)............/(b)............/(c)/(d)........... Only first attempt will be considered for evaluation. 10. Draw well labeled diagrams and write balanced equations wherever necessary. 11. Every new section must be started on a new page. 12. Given data: - Atomic mass of C=12, H=1, O=16, - Atomic number (Z): Mn=25, Fe=26, Ce= 58, Ar= 18, - R = 8.314 JK−¹ mol−¹ or 0.083 L bar K−¹ mol−¹ ### Section A **Q.1. Select and write the correct answer :** 1. For pH > 7, the hydronium ion concentration would be - (A) 10^7 M - (B) < 10^-7 M - (C) > 10^-7 M - (D) ≥10^-7 M 2. CH₂OH–CO–(CHOH)₄–CH₂OH is an example of - (A) aldohexose - (B) aldoheptose - (C) ketotetrose - (D) ketoheptose 3. CH₃-CH=CH₂ peroxide HI The major product of the above reaction is, - (A) I-CH₂-CH=CH₂ - (B) CH₃-CH₂-CH₂I - (C) CH₃-CH-CH₃ - (D) CH₃-CH-CH₂ - | | - I OH 4. Which is the most resistant alcohol towards oxidation reaction among the following? - (A) CH₃-CH₂-OH - (B) (CH₃)₂CH - OH - (C) (CH₃)₃C - OH - (D) C₂H₅CH - OH - | - CH₃ 5. Cryoscopic constant depends on - (A) nature of solvent - (B) nature of solute - (C) nature of solution - (D) number of solvent molecules 6. A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 bar from an initial volume of 2.5 L to a final volume of 4.5 L. The change in internal energy, ΔU of the gas will be - (A) -500 J - (B) +500 J - (C) -1013 J - (D) + 1013 J 7. Which of the following have d⁰s configuration? - (A) Sc³+ - (B) Ti⁴+ - (C) V⁵+ - (D) All of the above 8. Chlorine reacts with excess of fluorine to form - (A) CIF - (B) CIF₃ - (C) CIF₂ - (D) Cl₂F₃ 9. Aldol condensation is - (A) electrophilic substitution reaction - (B) nucleophilic substitution reaction - (C) elimination reaction - (D) addition - elimination reaction 10. Which of the following is made up of polyamides? - (A) Dacron - (B) Rayon - (C) Nylon - (D) Jute **Q. 2. Answer the following :** 1. Write the relationship between conductivity and molar conductivity and hence unit of molar conductivity. 2. For the reaction, N₂(g)+3H₂(g)→2NH₃(g), what is the relationship among $\frac{d[N₂]}{dt}$, $\frac{d[H₂]}{dt}$ and $\frac{d[NH₃]}{dt}$? 3. Write the structure of isoprene. 4. Define green chemistry. 5. Draw a neat diagram for the zwitter ion. 6. Write probable electronic configurations of chromium. 7. Name the Lewis acids and bases in the complex [PtCl₂(NH₃)₂]. 8. State Markovnikov's rule. ### Section B **Attempt any Eight :** **Q. 3.** Write a note on Stephen reaction. **Q. 4.** A solution of citric acid C₆H₈O₇ in 50 g of acetic acid has a boiling point elevation of 1.76 K. If K for acetic acid is 3.07 K kg mol−¹, what is the molality of solution? **Q. 5.** Comment on the statement: no work is involved in an expansion of gas in vacuum. **Q. 6.** Predict the major product in the following reactions: - i. *HO - C=O* acidified K₂Cr₂O₇ - ii. *CH=CH-C=O* Tollens reagent A A **Q. 7.** Why salts of Sc³+, Ti⁴+, V⁵+ are colourless? **Q. 8.** Write the chemical reactions involved in manufacture of Nylon 6,6. **Q. 9.** How many moles of electrons are passed when 0.8 ampere current is passed for 1 hour through molten CaCl₂? **Q. 10.** Distinguish between ionic solids and molecular solids. **Q. 11.** The half life of first order reaction is 990 s. If the initial concentration of the reactant is 0.08 mol dm−³, what concentration would remain after 35 minutes? **Q. 12.** Give reasons: Haloarenes are less reactive than haloalkanes. - i. Chlorobenzene - ii. Benzene sulfonic acid. **Q. 13.** Give the reagents and conditions necessary to prepare phenol from - i. Chlorobenzene - ii. Benzene sulphonic acid **Q. 14.** An alcoholic compound was found to have molecular mass of 90 u. It was acetylated. Molecular mass of the acetyl derivative was found to be 174 u. How many alcoholic (-OH) groups must be present in the original compound? ### Section C **Attempt any Eight :** **Q. 15.** Derive Ostwald's dilution law for CH₃COOH. **Q. 16** 22 g of CO₂ are compressed isothermally and reversibly at 298 K from initial pressure of 100 kPa when the work obtained is 1.2 kJ. Find the final pressure. **Q. 17.** Explain why phenol is more acidic than ethyl alcohol. **Q.18.** The density of iridium is 22.4 g/cm³. The unit cell of iridium is fcc. Calculate the radius of iridium atom. Molar mass of iridium is 192.2 g / mol. **Q. 19.** Define the following terms: - i. Nanoscience - ii. Nanotechnology - iii. Nanomaterial **Q. 20.** Using Raoult's law, how will you show that $ΔP= P_x₂$? Where, $x_2$ is the mole fraction of solute in the solution and P vapour pressure of pure solvent. **Q. 21.** Write IUPAC names of the following. - i. $Br$ - $CH₃-CH-CH₃$ - ii. - iii. $CH₃-CH=CH-CH_2Cl$ - $H_3C$ - $CCH-CH_2I$ - $HC$ **Q. 22.** What is zeroth order reaction? Derive its integrated rate law. What are the units of rate constant? **Q. 23.** Write a note on Cannizzaro reaction. **Q. 24.** What is the action of following on SO₂? - i. Cl₂ - ii. O₂ - iii. NaOH **Q. 25.** - i. What is difference between a double salt and a complex? Give an example. - ii. What is the shape of a complex in which the coordination number of central metal ion is 4? **Q. 26.** - i. Using the relationship ΔGº of cell reaction and the standard potential associated with it, how will you show that the electrical potential is an intensive property? - ii. Sketch the diagram of standard hydrogen electrode. ### Section D **Attempt any Three :** **Q. 27.** - i. Using the relationship ΔGº of cell reaction and the standard potential associated with it, how will you show that the electrical potential is an intensive property? - ii. Sketch the diagram of standard hydrogen electrode. **Q. 28.** - i. State and explain Kirchhoff's current law in electric circuit. - ii. Figure shows currents in a part of electrical circuit. Find the current X. **Q. 29.** Write the names and structural formulae of oxoacids of chlorine. **Q. 30.** - i. Predict the product of the following reaction: *Nitrobenzene →?* - ii. Explain. Gabriel phthalimide synthesis. **Q. 31.** - i. What are cationic, anionic and neutral complexes? Give one example of each. - ii. Dissociation constant of acetic acid is 1.8 × 10⁻⁵. Calculate percent dissociation of acetic acid in 0.01 M solution. - iii. Obtain the expression for work done in a chemical reaction. ## Maths and Statistics **Time : 3 Hours** **Total Marks: 80** ### General Instructions : 1. The question paper is divided into FOUR sections. 2. **Section A :** Q.1 contains Eight multiple choice questions carrying Two marks each. Q.2 contains Four very short answer type questions carrying One mark each. 3. **Section B:** contains Twelve short answer type questions carrying Two marks each. (Attempt any Eight) 4. **Section C:** contains Twelve short answer type questions carrying Three marks each. (Attempt any Eight) 5. **Section D:** contains Eight long answer type questions carrying Four marks each. (Attempt any Five) 6. Use of log table is allowed. Use of calculator is not allowed. 7. Figures to the right indicate full marks. 8. Use of graph paper is not necessary. Only rough sketch of graph is expected. 9. For each MCQ, correct answer must be written along with its alphabet: e.g.(a)........... / (b)............/(c) ......../ (d)......... Only first attempt will be considered for evaluation. 10. Start answers to each section on a new page. ### Section A **Q. 1. Select and write the most appropriate answer from the given alternatives for each sub-question:** 1. Inverse of statement pattern (p v q) → (p∧q) is - (A) (p∧q) → (p v q) - (B) ~(p∧q) → (p∧q) - (C) (~p∧~q)→(~p v ~q) - (D) (~p v ~q)→(~p∧~q) 2. If A = $ \begin{bmatrix} 1 & 2 \\ 3 & 4 \end{bmatrix} $ and A(adj A) = k I, then the value of k is - (A) 2 - (B) 2/5 - (C) 10 - (D) -10 3. If α, β, y are direction angles of a line and a = 60°, B = 45°, then y = - (A) 30° or 60° - (B) 45° or 60° - (C) 90° or 30° - (D) 60° or 120° 4. If the line $ \frac{x}{4} = \frac{y}{3} = \frac{z}{4} $ is perpendicular to the line $ \frac{x-1}{k} = \frac{y+2}{3} = \frac{z-3}{k-1} $, then the value of k is - (A) 11/4 - (B) 11/4 - (C) 11/2 - (D) 4/11 5. $ ∫e^(x-1) dx$= - (A) $ \frac{e^x}{x-1} + c $ - (B) $ \frac{e^x}{x} + c$ - (C) $ \frac{1}{(x-1)^2} e^x + c$ - (D) $xe^x +c$ 6. The area bounded by the region 1≤ x ≤ 5 and 2 ≤ y ≤ 5 is given by - (A) 12 sq. units - (B) 8 sq. units - (C) 25 sq. units - (D) 32 sq. units 7. The order and degree of the differential equation $1+\frac{dy}{dx} - \frac{d^2y}{dx^2} = (\frac{d^3y}{dx^3})^2$ are respectively - (A) 2,1 - (B) 1,2 - (C) 3,2 - (D) 2,3 8. If the p. d. f. of a c. r. v. X is - $ f(x) = \frac{x^2}{18}$, for -3 < x < 3 - = 0, otherwise, then P (|X| < 1) = - (A) $ \frac{1}{27}$ - (B) $ \frac{1}{28}$ - (C) $ \frac{1}{29}$ - (D) $ \frac{1}{26}$ **Q. 2. Answer the following questions:** 1. Write the negation of the following. - ∀n ∈ N, n²+n+ 2 is divisible by 4. 2. Find the principal value of $ sin⁻¹(\frac{1}{2})$. 3. If y = $e^x$, find $\frac{dy}{dx}$. 4. If X~B(n, p) and p = 0.6, E(X) = 6, find n. ### Section B **Attempt any EIGHT of the following questions:** **Q. 3.** If statements p, q are true and r, s are false, determine the truth value of (p∧~r)^(~q v s). **Q. 4.** In ΔABC, prove that a(b cos C - c cos B) = b²-c². **Q. 5.** Find k if one of the lines given by 6x²+kxy+y²=0 is 2x+y=0. **Q. 6.** Find the direction ratios of a vector perpendicular to the two lines whose direction ratios are -2, 1, -1 and -3, -4, 1. **Q. 7.** If the vectors 2i-qj+3k and 41-5j+6k are collinear, then find the value of q. **Q. 8.** Find the vector equation of a plane which is at 42 unit distance from the origin and which is normal to the vector 2 i + j-2k. **Q. 9.** Find $ \frac{dy}{dx}$, if x = a cot θ, y = b cosec θ. **Q. 10.** The displacement of a particle at time t is given by s = 2t²- 5t²+4t-3 Find the time when the acceleration is 14 ft/sec². **Q. 11.** Evaluate: $∫ cos²x dx $ **Q. 12.** Evaluate: $ ∫e*(1+x) dx$ **Q. 13.** Evaluate: $∫\frac{log(2+ sinx)}{cos^2x} dx$. **Q. 14.** Find the area of the region bounded by the curve y² = x, X-axis and the lines x = 0, x = 4. ### Section C **Attempt any EIGHT of the following questions:** **Q. 15.** Write converse, inverse and contrapositive of the following statement. If surface area decreases then pressure increases. **Q. 16.** Show that 2 $sin⁻¹(\frac{3}{5})- sin⁻¹(\frac{24}{25}) = tan⁻¹ (\frac{7}{24})$. **Q. 17.** If A (a) and B(5) are any two points in the space and R(r) be a point on the line segment AB dividing it internally in the ratio m: n, then prove that $r = \frac{mb+na}{m+n}$. **Q. 18.** Prove that : (a+2b г). [(b)×(c)] = 3 [abc]. **Q. 19.** Find the shortest distance between the lines $r= (4i-j)+(i+2j-3k)$ and $r= (i-j+2k) + µ(i+4j-5k)$. **Q. 20.** Find the vector equation of the plane passing through the points A(1, 2, 1), B(2, -1, -3) and C(0, 1, 5). **Q. 21.** If y = (sin x)*, then find $\frac{dy}{dx}$. **Q. 22.** If sin y = x sin (a + y), then show that $ \frac{dy}{dx} = \frac{sin²(a + y)} {sin a}$. **Q. 23.** Find the approximate value of $log₁₀ (10¹⁶)$, given that $log₁₀ e = 0.4343$. **Q. 24.** The slope of the tangent to the curve at each of its point is equal to the sum of abscissa and the product of the abscissa and ordinate of the point. Also the curve passes through the point (0, 1). Find the equation of the curve. **Q. 25.** Solve the differential equation : $ \frac{dy}{dx} = x tan ( \frac{y}{x} ) $ **Q. 26.** Let X be amount of time for which a book is taken out of library by randomly selected student and suppose X has p.d.f. - $ f(x) = 0.5x$, for 0≤x≤ 2 and - = 0, otherwise. Calculate: - i. P (X≤1) - ii. P (0.5 ≤ X ≤ 1.5) - iii. P (X≥ 1.5) ### Section D **Attempt any FIVE of the following questions:** **Q. 27.** The cost of 4 pencils, 3 pens and 2 erasers is₹60. The cost of 2 pencils, 4 pens and 6 erasers is₹90, whereas the cost of 6 pencils, 2 pens and 3 erasers is₹70. Find the cost of each item by using matrices. **Q. 28.** Find the general solution of cos θ + sin θ = 1. **Q. 29.** If θ is the measure of acute angle between the pair of lines given by ax² + 2hxy + by² = 0, then prove that $ tan θ = \frac{2√(h²-ab)}{a+b}$, a+b≠0. Find the condition for coincident lines. **Q. 30.** Solve the following L. P. P. by graphical method: Minimize: Z = 7x + y subject to 5x+y≥5, x+y≥3, x≥0, y≥0. **Q. 31.** Prove that : $∫√(x²-a²) dx = \frac{x√(x²-a²)-a² log|x+√(x²-a²)| + c}{2}$ **Q. 32.** A wire of length l is cut into two parts. One part is bent into a circle and the other into a square. Show that the sum of the areas of the circle and the square is least, if the radius of the circle is half the side of the square. **Q. 33.** Show that : $∫^a_0 f(x)dx = ∫^a_0 f(x)dx +∫^a_0f(2a-x)dx$. **Q. 34.** Five cards are drawn successively with replacement from a well-shuffled deck of 52 cards. Find the probability that - i. all the five cards are spades. - ii. only 3 cards are spades. - iii. none is a spade. ## Biology **Time: 3 Hours** **Total Marks: 70** ### General Instructions: 1. The question paper is divided into four sections. 2. **Section A:** Q.No.1 contains Ten multiple choice type of questions carrying One mark each. Q.No.2 contains Eight very short answer type of questions carrying One mark each. 3. **Section B:** Q.No.3 to Q.No. 14 are short answer type of questions carrying Two marks each. 4. **Section C:** Q.No.15 to Q.No.26 contains are short answer type of questions carrying Three marks each. 5. **Section D:** Q.No.27 to Q.No.31 are long answer type of questions carrying Four marks each. 6. Figures to the right indicate full marks. 7. For each MCQ, correct answer must be written along with its alphabet. E.g., (a)............/(b)............/(c)/(d)........... Only first attempt will be considered for evaluation. ### Section A **Q. 1. Select and write the correct answer:** 1. When pollen tube enters ovule through integuments it is called as - (A) syngamy - (B) porogamy - (C) chalazogamy - (D) mesogamy 2. Rupturing of follicles and discharge of ova is known as - (A) capacitation - (B) gestation - (C) ovulation - (D) copulation 3. Water absorption takes place through - (A) lateral roots - (B) root cap - (C) root hair - (D) primary root 4. Select an appropriate plant hormone responsible for apical dominance from the following. - (A) Auxins - (B) Ethylene - (C) Gibberellins - (D) Cytokinins 5. ______ is a sound producing organ. - (A) Larynx - (B) Pharynx - (C) Tonsils - (D) Trachea 6. Hormones thyroxine, adrenaline and nor adrenaline are formed from