IISER IAT 2025 question paper

1. A.
   P - iv; Q - i; R - ii; S - iii
2. B.
   P - iv; Q - ii; R - i; S - iii
3. C.
   P - iii; Q - i; R - ii; S - iv
4. D.
   P - i; Q - iii; R - ii; S - iv

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1. A.
   Centromere
2. B.
   Telomere
3. C.
   Centriole
4. D.
   Centrosome

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1. A.
   Three fatty acid chains linked to a molecule of glycerol
2. B.
   Three glycerol molecules linked to a fatty acid chain
3. C.
   Three glyceride molecules linked to a molecule of phospholipid
4. D.
   Three saturated fatty acid chains linked to a molecule of cholesterol

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1. A.
   It protects chlorophyll a from photo-oxidation.
2. B.
   It accumulates in chromoplasts during fruit ripening.
3. C.
   It provides precursor for the synthesis of stress hormone in plants.
4. D.
   It is an accessory pigment which absorbs light at 600 - 700 nm.

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1. A.
   Experiment 1 $<$ Experiment 2 $<$ Experiment 3
2. B.
   Experiment 1 $=$ Experiment 2 $=$ Experiment 3
3. C.
   Experiment 2 $<$ Experiment 1 $=$ Experiment 3
4. D.
   Experiment 2 $<$ Experiment 1 $<$ Experiment 3

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1. A.
   Levels of renin, angiotensin I and II and aldosterone are increased.
2. B.
   Levels of renin and aldosterone are reduced.
3. C.
   Levels of angiotensin I and II are increased, while that of aldosterone are reduced.
4. D.
   Levels of renin are increased, while those of angiotensin I and II and aldosterone are reduced.

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1. A.
   lower $\mathrm{[H^+]}$; lower temperature
2. B.
   lower $\mathrm{[H^+]}$; higher temperature
3. C.
   higher $\mathrm{[H^+]}$; higher temperature
4. D.
   higher $\mathrm{[H^+]}$; lower temperature

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1. A.
   Mitochondria are more in white than in red muscle fibres.
2. B.
   All muscle fibres primarily produce ATP anaerobically.
3. C.
   Lactic acid accumulates more in red than in white muscle fibres under similar conditions.
4. D.
   Red muscle fibres produce ATP aerobically under normal oxygen conditions.

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1. A.
   Fruit fly
2. B.
   Chicken
3. C.
   Honey bee
4. D.
   Garden pea

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1. A.
   Leucine (codon UUG)
2. B.
   Asparagine (codon AAC)
3. C.
   Glutamine (codon CAA)
4. D.
   Valine (codon GUU)

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1. A.
   R1 = ppQQ ; R2 = PPqq ; R3 = PPqq ; R4 = ppQQ
2. B.
   R1 = PPQQ ; R2 = ppqq ; R3 = ppqq ; R4 = PPQQ
3. C.
   R1 = PPQQ ; R2 = ppqq ; R3 = ppQQ ; R4 = PPqq
4. D.
   R1 = ppQQ ; R2 = PPqq ; R3 = PPQQ ; R4 = ppqq

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1. A.
   A group of viruses with DNA genome and no reverse transcriptase activity
2. B.
   A group of viruses with RNA genome and reverse transcriptase activity
3. C.
   A group of viruses with DNA genome and reverse transcriptase activity
4. D.
   A group of viruses with RNA genome and no reverse transcriptase activity

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1. A.
   Circular plasmid pIAT25 with X sites at 9235 bp and 6235 bp, and Y sites at 1235 bp and 4235 bp
2. B.
   Circular plasmid pIAT25 with X sites at 9235 bp and 4235 bp, and Y sites at 1235 bp and 6235 bp
3. C.
   Circular plasmid pIAT25 with Y sites at 9235 bp and 6235 bp, and X sites at 1235 bp and 4235 bp
4. D.
   Circular plasmid pIAT25 with X sites at 9235 bp and 1235 bp, and Y sites at 6235 bp and 4235 bp

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1. A.
   Honey bee males are produced from unfertilized eggs and females are produced from fertilized eggs.
2. B.
   Honey bee males cannot have daughters but can have sons.
3. C.
   Honey bee males form gametes by mitosis and females form gametes by meiosis.
4. D.
   A honey bee male does not have a father but has a grandfather.

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1. A.
   The movement of energy is unidirectional in the ecological pyramid of energy.
2. B.
   More than 80% of the solar energy incident on earth is captured by plants and photosynthetic bacteria.
3. C.
   All organisms of a trophic level should be included for estimation of energy content of that trophic level.
4. D.
   Only 10% of energy is transferred to each of the higher trophic levels in grazing food chain.

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1. A.
   Both $\mathrm{ZnO}$ and $\mathrm{CaO}$ are amphoteric.
2. B.
   $\mathrm{ZnO}$ is acidic, while $\mathrm{CaO}$ is basic.
3. C.
   $\mathrm{ZnO}$ is basic, while $\mathrm{CaO}$ is amphoteric.
4. D.
   $\mathrm{ZnO}$ is amphoteric, while $\mathrm{CaO}$ is basic.

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1. A.
   (ii) and (iii)
2. B.
   (i) and (ii)
3. C.
   (ii) only
4. D.
   (iii) only

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1. A.
   $0.33\ \mathrm{V}$
2. B.
   $-0.04\ \mathrm{V}$
3. C.
   $-0.11\ \mathrm{V}$
4. D.
   $0.11\ \mathrm{V}$

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1. A.
   $\mathrm{VCl_5 > VF_5}$ ; $\mathrm{CuCl_2 > CuI_2}$
2. B.
   $\mathrm{VF_5 > VCl_5}$ ; $\mathrm{CuCl_2 > CuI_2}$
3. C.
   $\mathrm{VF_5 > VCl_5}$ ; $\mathrm{CuI_2 > CuCl_2}$
4. D.
   $\mathrm{VCl_5 > VF_5}$ ; $\mathrm{CuI_2 > CuCl_2}$

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1. A.
   Both P and Q show geometrical isomerism and P absorbs light of higher wavelength than that of Q.
2. B.
   P shows geometrical isomerism and absorbs light of lower wavelength than that of Q.
3. C.
   P shows geometrical isomerism and absorbs light of higher wavelength than that of Q.
4. D.
   Q shows geometrical isomerism and absorbs light of higher wavelength than that of P.

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1. A.
   3
2. B.
   2
3. C.
   4
4. D.
   1

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1. A.
   $\mathrm{C_6H_5CH_3} \xrightarrow[\mathrm{(ii)\ H_3O^+}]{\mathrm{(i)\ CrO_2Cl_2,\ CS_2}}$
2. B.
   $\mathrm{C_6H_5CN} \xrightarrow[\mathrm{(ii)\ H_3O^+}]{\mathrm{(i)\ SnCl_2,\ HCl}}$
3. C.
   $\mathrm{C_6H_5COCl} \xrightarrow{\mathrm{(C_6H_5CH_2)_2Cd}}$
4. D.
   $\mathrm{C_6H_5COCl} \xrightarrow{\mathrm{Pd\text{-}BaSO_4/H_2}}$

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1. A.
   $\mathrm{PhCH(OH)CH_2COCH_2CH_3}$ and $\mathrm{PhC(OH)(CH_3)CH_2CH_3}$
2. B.
   $\mathrm{Ph_3COH}$ and $\mathrm{PhC(OH)(CH_3)CH_2CH_3}$
3. C.
   $\mathrm{PhCHO}$ and $\mathrm{PhC(OH)(CH_3)CH_2CH_3}$
4. D.
   $\mathrm{Ph_2CHOH}$ and $\mathrm{PhC(OH)(CH_3)CH_2CH_3}$

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1. A.
   $\mathrm{Ph(CH_2)_3CHO}$
2. B.
   $\mathrm{Ph(CH_2)_4OH}$
3. C.
   $\mathrm{Ph(CH_2)_4NH_2}$
4. D.
   $\mathrm{Ph(CH_2)_3CH_3}$

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1. A.
   4,5-dimethylcyclohex-1-ene
2. B.
   1,2-dimethylcyclohex-1-ene
3. C.
   1,6-dimethylcyclohex-1-ene
4. D.
   1,3-dimethylcyclohex-1-ene

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1. A.
   $-\mathrm{R}T\ln\left(\frac{1}{15}\right)$
2. B.
   $\frac{1}{30}\mathrm{R}T$
3. C.
   $\frac{3}{8}\mathrm{R}T$
4. D.
   $\frac{3}{4}\ \mathrm{R}T$

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1. A.
   Plot of $t_{1/2}$ against $[\mathrm{R}]_0$: a curve rising ever more steeply
2. B.
   Plot of $t_{1/2}$ against $[\mathrm{R}]_0$: a horizontal straight line
3. C.
   Plot of $t_{1/2}$ against $[\mathrm{R}]_0$: a straight line falling
4. D.
   Plot of $t_{1/2}$ against $[\mathrm{R}]_0$: a straight line rising from near the origin

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1. A.
   2.4 femtoseconds
2. B.
   4.8 femtoseconds
3. C.
   24 femtoseconds
4. D.
   0.24 femtoseconds

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1. A.
   I: $\mathrm{BCl_3}$, II: $\mathrm{NH_3}$, III: $\mathrm{NF_3}$
2. B.
   I: $\mathrm{ClF_3}$, II: $\mathrm{NF_3}$, III: $\mathrm{NH_3}$
3. C.
   I: $\mathrm{BF_3}$, II: $\mathrm{NH_3}$, III: $\mathrm{NF_3}$
4. D.
   I: $\mathrm{BF_3}$, II: $\mathrm{NF_3}$, III: $\mathrm{NH_3}$

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1. A.
   $\mathrm{Pb \rightarrow Pb^{2+} + 2e^-}$
2. B.
   $\mathrm{Pb^{2+} \rightarrow Pb^{4+} + 2e^-}$
3. C.
   $\mathrm{Pb^{4+} + 4e^- \rightarrow Pb}$
4. D.
   $\mathrm{2Pb^{2+} \rightarrow Pb^{4+} + Pb}$

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1. A.
   144
2. B.
   162
3. C.
   128
4. D.
   136

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1. A.
   1
2. B.
   4
3. C.
   infinitely many
4. D.
   2

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1. A.
   $n$ is divisible by 6
2. B.
   $n$ is divisible by 5
3. C.
   $n$ is divisible by 9
4. D.
   $n$ is divisible by 8

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1. A.
   $f$ is decreasing on the interval $(-1, 1)$
2. B.
   $f$ is decreasing for $x < 0$
3. C.
   $f$ is decreasing for $x > 0$
4. D.
   $f$ is decreasing on $\mathbf{R}$

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1. A.
   $A = (-2, 2]$
2. B.
   $A = [-2, 2)$
3. C.
   $A = (-2, 2)$
4. D.
   $A = [-2, 2]$

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1. A.
   4
2. B.
   $\frac{1}{8}$
3. C.
   8
4. D.
   $\frac{1}{4}$

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1. A.
   Every integer is a point of discontinuity of $f$
2. B.
   $f$ is continuous at every real number
3. C.
   $f$ is continuous at every real number except for $0, \pm\sqrt{3}$
4. D.
   Every non-zero integer is a point of discontinuity of $f$

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1. A.
   $y = \sqrt{3}(x - 2)$
2. B.
   $4\sqrt{3}y = (x - 2)$
3. C.
   $y = 4\sqrt{3}(x - 2)$
4. D.
   $y = 2\sqrt{3}(x - 2)$

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1. A.
   $\sqrt{2}$
2. B.
   $\frac{3}{\sqrt{2}}$
3. C.
   3
4. D.
   0

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1. A.
   $\sin 2x$
2. B.
   $\cot x \operatorname{cosec} 2x$
3. C.
   $4 \operatorname{cosec} x$
4. D.
   $2 \operatorname{cosec} x$

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1. A.
   12
2. B.
   46
3. C.
   13
4. D.
   137

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1. A.
   $\frac{13}{16}$
2. B.
   $\frac{5}{16}$
3. C.
   $\frac{11}{16}$
4. D.
   $\frac{7}{16}$

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1. A.
   $f$ is neither one-one nor onto
2. B.
   $f$ is onto but not one-one
3. C.
   $f$ is one-one and onto
4. D.
   $f$ is one-one but not onto

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1. A.
   $12y = x^3 - \frac{1}{x^9}$
2. B.
   $9y = x^3 - \frac{1}{x^{21}}$
3. C.
   $12y = x^9 - \frac{1}{x^3}$
4. D.
   $9y = x^{21} - \frac{1}{x^3}$

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1. A.
   $\pi$
2. B.
   $\frac{\pi}{4}$
3. C.
   $\frac{\pi}{2}$
4. D.
   $\frac{\pi}{6}$

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1. A.
   x-t graph: solid A (steeper, from the origin) meets solid B (shallower, starting above the origin); after the meeting the steeper dotted line is B and the shallower dotted line is A. v-t graph: solid A above solid B before the collision; dotted A above dotted B after it
2. B.
   x-t graph: solid A (steeper, from the origin) meets solid B (shallower, starting above the origin); after the meeting the steeper dotted line is B and the shallower dotted line is A. v-t graph: solid B above solid A before the collision; dotted A above dotted B after it
3. C.
   x-t graph: solid A (steeper, from the origin) meets solid B (shallower, starting above the origin); after the meeting the steeper dotted line is B and the shallower dotted line is A. v-t graph: solid A above solid B before the collision; dotted B above dotted A after it
4. D.
   x-t graph: solid A (steeper, from the origin) meets solid B (shallower, starting above the origin); after the meeting the steeper dotted line is B and the shallower dotted line is A. v-t graph: solid B above solid A before the collision; dotted B above dotted A after it

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1. A.
   $\sqrt{\frac{m M v^2}{k(M + m)}}$
2. B.
   $\sqrt{\frac{M v^2}{k}}$
3. C.
   $\sqrt{\frac{m^2 v^2}{k(M + m)}}$
4. D.
   $\sqrt{\frac{m v^2}{k}}$

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1. A.
   $h_2$
2. B.
   $M$
3. C.
   $R$
4. D.
   $h_1$

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1. A.
   $\theta = -\frac{\omega^2 M R^2}{8T}$
2. B.
   $\theta = \frac{\omega^2 M R^2}{4T}$
3. C.
   $\theta = -\frac{\omega^2 M R^2}{4T}$
4. D.
   $\theta = \frac{\omega^2 M R^2}{8T}$

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1. A.
   $1.56 \times 10^{-6}\%$
2. B.
   $0.75\%$
3. C.
   $6.25 \times 10^{-6}\%$
4. D.
   $0.50\%$

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1. A.
   $T_A = \left(\frac{n_A^2}{4n_B^2}\right) T_B$
2. B.
   $T_A = \left(\frac{4n_A^2}{n_B^2}\right) T_B$
3. C.
   $T_A = \left(\frac{n_B^2}{4n_A^2}\right) T_B$
4. D.
   $T_A = \left(\frac{4n_B^2}{n_A^2}\right) T_B$

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1. A.
   $A_s = \frac{A}{2}$ and $\phi_s = \frac{\pi}{6}$
2. B.
   $A_s = 2A$ and $\phi_s = \frac{\pi}{6}$
3. C.
   $A_s = \frac{A}{2}$ and $\phi_s = \frac{\pi}{3}$
4. D.
   $A_s = 2A$ and $\phi_s = \frac{\pi}{3}$

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1. A.
   $\frac{l^2}{2d^2}$
2. B.
   $\frac{d^2}{l^2}$
3. C.
   $\frac{l^2}{d^2}$
4. D.
   $\frac{d^2}{2l^2}$

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1. A.
   0 V
2. B.
   12 V
3. C.
   4 V
4. D.
   8 V

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1. A.
   $r = \frac{2\pi m v_0}{3qB_0}$ and $p = \frac{2\sqrt{2} m v_0}{3qB_0}$
2. B.
   $r = \frac{2\sqrt{2} m v_0}{3qB_0}$ and $p = \frac{4\sqrt{2}\pi m v_0}{3qB_0}$
3. C.
   $r = \frac{2\sqrt{2} m v_0}{3qB_0}$ and $p = \frac{2\pi m v_0}{3qB_0}$
4. D.
   $r = \frac{m v_0}{3qB_0}$ and $p = \frac{2\pi m v_0}{3qB_0}$

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1. A.
   Both the radius of the orbit and the frequency will remain unchanged.
2. B.
   The radius of the orbit will gradually increase and the frequency will gradually decrease.
3. C.
   The radius of the orbit will gradually decrease and the frequency will gradually increase.
4. D.
   The radius of the orbit will remain the same but the frequency will gradually increase.