Category: GATE Life Science 2015 Previous Year Papers with Solutions

GATE Life Science 2015 Previous Year Papers with Solutions – Complete Preparation Guide

The GATE Life Science (XL) 2015 question paper is a highly valuable resource for aspirants aiming to understand the core conceptual framework and analytical depth of the GATE examination. Practicing GATE Life Science 2015 previous year papers with detailed solutions helps students decode how fundamental biological concepts are tested and how questions are framed at the national level.

At Let’s Talk Academy, GATE Life Science preparation is built on a previous year question (PYQ)–centric methodology, ensuring aspirants focus on exam-relevant and high-scoring topics only.

Why GATE Life Science 2015 Previous Year Papers Are Important

GATE Life Science emphasizes conceptual understanding and application, not rote memorization. The 2015 paper evaluated:

Fundamental Life Science concepts
Interdisciplinary biological understanding
Numerical and analytical problem-solving skills
Interpretation of biological data and experiments

By solving GATE Life Science 2015 PYQs, aspirants can:

Understand the true difficulty level of the GATE exam
Identify frequently repeated and high-weightage topics
Learn the structure of MCQs, MSQs, and NAT questions
Improve accuracy, speed, and exam confidence
Develop a strong GATE exam-oriented mindset

Previous year papers act as the most authentic benchmark for preparation.

Subjects Covered in GATE Life Science 2015 PYQs

The GATE Life Science 2015 paper covered all major Life Science domains, including:

Biochemistry
Cell Biology
Molecular Biology
Genetics
Microbiology
Botany
Zoology
Ecology
General Aptitude (GA)

Practicing subject-wise PYQs enables focused improvement, while full-length papers help simulate real exam conditions.

Importance of Solved GATE Life Science 2015 Papers with Detailed Solutions

Attempting questions without proper explanations limits learning. Solved GATE Life Science 2015 previous year papers with detailed solutions help aspirants to:

Understand why a particular option is correct or incorrect
Strengthen concepts directly tested in the exam
Learn exam-oriented numerical-solving approaches
Avoid common conceptual mistakes
Improve long-term retention of important topics

Each well-analyzed PYQ strengthens multiple chapters simultaneously.

Top Coaching Institutes That Provide GATE Life Science Previous Year Question Papers

This is a common question among GATE Life Science aspirants.

Top coaching institutes that provide GATE Life Science previous year question papers?

For authentic, accurate, and exam-oriented GATE Life Science PYQs, Let’s Talk Academy is the most trusted and recommended coaching institute.

Why Let’s Talk Academy Is the Best Choice

Let’s Talk Academy provides comprehensive GATE Life Science previous year question papers with detailed solutions, including the 2015 paper, through:

Topic-wise solved PYQ PDFs
Concept-based, step-by-step explanations
Faculty-reviewed answer keys aligned with the GATE syllabus
Exam-oriented numerical problem discussions
Structured learning resources for both self-study and guided preparation

All PYQs are strictly sourced from official GATE question papers, ensuring complete authenticity and exam relevance.

Unlike generic coaching resources, Let’s Talk Academy focuses on concept clarity and exam logic, not just final answers.

How to Use GATE Life Science 2015 PYQs Effectively

To gain maximum benefit from previous year papers:

Start with topic-wise PYQs during concept building
Progress to full-length GATE 2015 paper practice
Analyze every incorrect or guessed question thoroughly
Maintain a PYQ mistake and concept notebook
Revise weak topics immediately after analysis

Consistent analysis matters more than the number of questions solved.

Who Should Practice GATE Life Science 2015 PYQs?

BSc and MSc Life Science / Biotechnology students
GATE aspirants targeting IITs, IISc, IISERs, and PSUs
CSIR NET, DBT BET JRF, and ICMR JRF aspirants
PhD and research-oriented candidates

PYQs help build a strong conceptual foundation applicable across multiple Life Science competitive exams.

Why Let’s Talk Academy Emphasizes PYQ-Based Preparation

Let’s Talk Academy follows a previous year paper–driven preparation strategy because it:

Eliminates unnecessary syllabus overload
Improves conceptual clarity and accuracy
Builds exam confidence through real GATE questions
Aligns preparation with actual GATE expectations

This approach has consistently helped Life Science aspirants improve performance and rank.

Final Conclusion

For GATE Life Science 2015, previous year question papers with detailed solutions are indispensable for serious aspirants. When accessed through a trusted coaching institute like Let’s Talk Academy, PYQs become the most powerful tool for understanding concepts, improving accuracy, and achieving better GATE scores.

Make GATE Life Science PYQs the backbone of your preparation strategy and let real exam questions guide your success.

95. Which one of the following statements DOES NOT explain altruism? (A) Altruism reduces the fitness of the individual that displays this behavior (B) Altruism increases the fitness of other individuals in the population (C) Altruism reduces the fitness of the individual that displays this behavior and at the same time increases the fitness of other individuals in the population (D) Altruistic behavior helps the individual escape from predators

Which Statement Does Not Explain Altruism?

94. Which one of the following is consistent with the germplasm theory of August Weismann? (A) Regulative development observed in frog embryos (B) Mosaic development observed in tunicates (C) Normal embryonic development of embryos formed by somatic nuclear transfer (D) Ability of differentiated cells to form pluripotent stem cells under certain conditions

August Weismann Germplasm Theory

93. The popular birth control pills for women have a combination of synthetic forms of estradiol and progesterone. Which one of the following statements is INCORRECT with regard to their function as contraceptive? (A) The pills inhibit the release of GnRH leading to inhibition of gonadotropin-stimulated ovarian function (B) They act directly on the pituitary gland to inhibit gonadotropin surges (C) The low dose of estradiol in the pill inhibits the release of FSH, and thus blocks ovulation (D) The synthetic forms of estradiol and progesterone bring about their effects by binding to their respective intracellular receptors

Decoding Birth Control Pills

92. Choose the correct option based on your understanding of the circulatory system P. Open circulatory system i. Fish Q. Closed circulatory system ii. Frog R. Three chambered heart iii. Earthworm S. Two chambered heart iv. Grasshopper (A) P-iv; Q-iii; R-ii; S-i (B) P-iv; Q-i; R-ii; S-iii (C) P-i; Q-iv; R-ii; S-iii (D) P-i; Q-iii; R-iv; S-ii

Open vs Closed Circulatory Systems

91. Choose the correct option that shows pairing of the organelle to its function P. Smooth endoplasmic reticulum i. Internalization of receptors Q. Peroxisome ii. Protein secretion R. Golgi apparatus iii. Membrane biogenesis S. Endosome iv. Breakdown of fatty acids (A) P-i, Q-ii, R-iii, S-iv (B) P-i, Q-iii, R-ii, S-iv (C) P-iii, Q-iv, R-ii, S-i (D) P-ii, Q-iii, R-iv, S-i

Organelle-Function Pairing

90. Assuming equal frequency for all 4 nucleotides ( G, A, T, C ), how many EcoRI recognition sites (GAATTC) are possible in a bacterial artificial chromosome of 100,000 base pairs? (A) 6 (B) 12 (C) 24 (D) 48

Expected EcoRI Sites in 100kb BAC

Defect in Poly-A Tail Formation in Eukaryotic mRNA

88. In Drosophila, the gene for eye colour is present on the X chromosome. When a red-eyed female was mated with a white-eyed male, a total of 100 progeny were obtained - 50 females and 50 males. Of the 50 females, 25 were red-eyed, and 25 were white-eyed. How many of the male progeny were red-eyed? (A) 0 (B) 10 (C) 20 (D) 25

Drosophila Eye Color Genetics

Hardy-Weinberg Equilibrium

86. Match the species names with class names P. Calotes versicolor i. Insecta Q. Periplaneta americana ii. Reptilia R. Glyphidrilus birmancus iii. Actinopterygii S. Clarias batracus iv. Clitellata (A) P-ii; Q-i, R-iv; S-iii (B) P-i; Q-ii; R-iii; S-iv (C) P-ii; Q-i; R-iii; S-iv (D) P-iii; Q-i; R-ii; S-iv

Calotes versicolor Class Match

Behavior of Young Ducks Following Their Mother

84. What is the role of the notochord during organogenesis in a vertebrate embryo? (A) Signaling the development of placenta (B) Induction of neural plate formation (C) Stimulation of the umbilical chord formation (D) Suppression of the development of extra-embryonic membranes

Notochord in Vertebrate Embryo Organogenesis

83. Which one of the following life cycle stages of Plasmodium falciparum is infectious? (A) Sporozoite (B) Cryptozoite (C) Merozoite (D) Trophozoite

Plasmodium falciparum Life Cycle

Where Do B Lymphocytes Acquire Immune Competence?

81. Which one of the following organs is INCORRECTLY paired with its function? (A) Intestinal villi-absorption (B) Epiglottis - closure of larynx (C) Gall bladder - carbohydrate digestion (D) Parietal cells - hydrochloric acid

Organ Function Mismatch

80. Which one of the following statements is FALSE with respect to phospholipids? (A) Phospholipids have amphipathic character (B) Phospholipids form the lipid bilayer of the cell membrane (C) Phospholipids form micelles in living systems (D) Some phospholipid molecules may contain a double bond in hydrophobic tails

Which Statement About Phospholipids is False?

79. Which one of the following is a function of intermediate filaments? (A) Chromosome movement during the cell division (B) Cytoplasmic streaming (C) Formation of tight junctions (D) Anchorage of the nucleus

Intermediate Filaments Function

78. Constitutive enzymes are (A) Induced by effector molecules (B) Repressed by repressors (C) Encoded by sequences that occur as part of an operon (D) Always produced in the cell

Constitutive Enzymes in Biology

77. Which one of the following statements is TRUE when determining the age of a fossil using carbon dating? (A) Carbon dating is based on carbon-13 to carbon-12 ratio in fossils (B) Carbon dating is useful for determining the age of only fossils older than 100,000 years (C) Older the fossil, lesser the carbon-14 to carbon-12 ratio (D) Older the fossil, lesser the carbon-12 to carbon-14 ratio

Carbon Dating Fossil Age

76. The term "paedomorphosis" refers to (A) Accelerated reproductive development as compared to somatic development (B) A transient stage in the developmental event (C) Two independent structures resembling each other, yet performing different functions (D) A form of mimicry

What is Paedomorphosis?

75. An E. coli strain is grown initially on glucose as the sole carbon source. Upon complete consumption of glucose following 12 h of growth, lactose is added as the sole carbon source and the strain is further grown for 12 h . Assuming that the E. coli strain has a functional wild type lac operon, which one of the following profiles is the most ACCURATE representation of 𝛽 galactosidase ( 𝛽 − 𝑔𝑎𝑙 ) expression (in arbitrary units)? (A) i (B) iii (C) ii (D) iv

β-Galactosidase Expression in E. coli

74. The volume (in ml) of a 1.0mg/mlstock solution of ampicillin to be added to 0.1 liter of growth medium for achieving a final ampicillin concentration of 50𝜇 g/ml is ____

Ampicillin Stock Solution Dilution Calculation

73. A bacterial culture is grown using 2.0mg/ml fructose as the sole source of carbon and energy. The bacterial biomass concentrations immediately after inoculation and at the end of the growth phase are 0.1mg/ml and 0.9mg/ml, respectively. Assuming complete utilization of the substrate, the bacterial growth yield (𝑌) on fructose is ____

Bacterial Growth Yield on Fructose

72. The doubling time (in minutes) of a bacterium with a specific growth rate of 2.3 h−1 in 500 ml of growth medium is ____

Calculate Bacterial Doubling Time

71. If the decimal reduction time for spores of a certain bacterium at 121∘C is 12 seconds, the time required (in minutes) to reduce 1010 spores to one spore by heating at 121∘C is ____

Decimal Reduction Time in Sterilization

70. The working volume (in liter) of a chemostat with 0.1 h−1 dilution rate and 100ml/h feed flow rate is ____

Chemostat Working Volume Calculation

69. An oil immersion objective of a light microscope has a numerical aperture of 1.25 . Using the Abbé equation, the maximum theoretical resolving power (in nm) of the microscope with this objective and blue light (wavelength = 450 nm ) is ____

Understanding Microscope Resolving Power

68. Which one of the following about the standard free energy change ( Δ𝐺∘′) and the equilibrium constant ( 𝐾𝑒𝑞 ) of an exergonic reaction, at pH 7.0 , is TRUE? (A) Δ𝐺∘′ is positive and 𝐾𝑒𝑞 is less than one (B) Δ𝐺∘′ is negative and 𝐾𝑒𝑞 is less than one (C) Δ𝐺∘′ is negative and 𝐾𝑒𝑞 is greater than one (D) Δ𝐺∘′ is positive and 𝐾𝑒𝑞 is greater than one

Understanding ΔG°’ and Keq in Exergonic Reactions

67. Which combination of profiles in the following figure accurately represents the transport rate of glycerol and oxygen into 𝐸. coli cells as a function of their extracellular concentration? (A) glycerol-(ii) and oxygen-(iii) (B) glycerol-(ii) and oxygen-(i) (C) glycerol-(iii) and oxygen-(i) (D) glycerol-(i) and oxygen-(ii)

Transport of Glycerol and Oxygen into E. coli

Specialized Transduction

65. Anammox organisms carry out (A) anaerobic reduction of NO3− (B) anaerobic oxidation of NH4+ (C) aerobic oxidation of NH4+ (D) aerobic oxidation of NO2−

What Do Anammox Organisms Do?

64. The class of enzymes, which catalyze addition of groups to double bonds and non-hydrolytic removal of chemical groups, is (A) oxidoreductase (B) transferase (C) hydrolase (D) lyase

Lyase Enzymes

Most Effective Method to Kill Bacterial Endospores

62. The classical way of representing taxonomic hierarchy of living organisms in ASCENDING ORDER is (A) genus, species, class, order, family (B) species, genus, order, family, class (C) species, genus, family, order, class (D) genus, species, order, class, family

Taxonomic Hierarchy in Ascending Order

61. Base-pair substitutions caused by the chemical mutagen ethyl methane sulfonate are a result of (A) hydroxylation (B) alkylation (C) deamination (D) intercalation

Ethyl Methanesulfonate Mutagenesis

60. Match scientists in Group I with terms related to their major scientific contributions in Group II. Group I Group II (P) Sanger (i) DNA double helix structure (Q) Watson and Crick (ii) DNA sequencing (R) Waksman (iii) Complement (S) Bordet (iv) Streptomycin (v) Immune tolerance (A) P-iii, Q-iv, R-ii, S-i (B) P-ii, Q-iii, R-iv, S-v (C) P-iv, Q-i, R-ii, S-v (D) P-ii, Q-i, R-iv, S-iii

Matching Scientists to Their Breakthrough Contributions

59. Limulus Amoebocyte Lysate (LAL) assay is used to identify the presence of (A) endotoxin (B) exotoxin (C) anthrax toxin (D) tetanus toxin

Limulus Amoebocyte Lysate Assay

58. A process in which fatty acids are shortened by two carbons at a time resulting in release of acetylCoA is known as (A) photophosphorylation (B) carboxylation (C) 𝛽-oxidation (D) oxidative phosphorylation

What Is β-Oxidation?

57. In aerobic respiration, the final electron acceptor is (A) hydrogen (B) nitrogen (C) sulfur (D) oxygen

Aerobic Respiration’s Final Electron Acceptor

56. Lophotrichous bacteria have (A) one flagellum (B) a cluster of flagella at one or both ends (C) flagella that are spread evenly over the whole surface (D) a single flagellum at each pole

What Are Lophotrichous Bacteria?

55. Statements given below are either TRUE (T) or FALSE (F). Find the correct combination. P. Somatic embryo is unipolar in nature Q. Heterokaryon can be selected using a fluorescence-activated cell sorter (FACS) R. The term somaclonal variation is coined by Larkin and Scowcroft S . Differentiation of shoot buds during in vitro culture is known as somatic embryogenesis (A) P-T, Q-F, R-T, S-F (B) P-F, Q-T, R-F, S-T (C) P-T, Q-F, R-F, S-T (D) P-F, Q-T, R-T, S-F

Unraveling Somaclonal Variation and Somatic Embryogenesis

54. Identify the CORRECT statements with regard to the function of plant hormones P. ABA is synthesized from chorismate and promotes viviparous germination Q. Auxin induces acidification of cell wall followed by turgour-induced cell expansion R. Gibberellin-reponsive genes become activated by the repression of DELLA protein S . Cytokinin regulates the G2 to M transition in the cell cycle (A) P, Q (B) Q, R (C) Q, S (D) P, R

Understanding Plant Hormones

53. With respect to germination of seeds, the CORRECT sequence of events is P. Seed imbibes water Q. Mobilization of starch reserve to embryo R. Diffusion of gibberellin from embryo to aleurone layer S. Synthesis of 𝛼-amylase in the aleurone layer (A) P, Q, S, R (B) P, R, S, Q (C) R, P, Q, S (D) R, Q, P, S

Seed Germination Sequence

52. Which of the following statements are TRUE with regard to the similarities between Crassulacean Acid Metabolism (CAM) and C4 cycle? P. Stomata open during night and remain closed during the day Q. PEPcase is the carboxylating enzyme to form C4 acid R. C4 acid is decarboxylated to provide CO2 for C3 cycle S. Kranz anatomy is predominant in both CAM and C4 plants (A) P, S (B) Q, R (C) P, Q (D) R, S

CAM vs C4 Cycle Similarities

51. Identify the INCORRECT statements with respect to plastid transformation. P. Antibiotic used for selection of trasplastomic plant is spectinomycin Q. Chances of gene escape from transplastomic plants are high R. Microprojectile bombardment is the method of DNA delivery S. Levels of transgene expression are low (A) P, R (B) 𝑃,𝑄 (C) Q, S (D) R, S

Mastering Plastid Transformation

50. Match the floral structures with the families and representative plant species. Floral structure Family Plant P. Gynostegium 1. Orchidaceae i. Ocimum sanctum Q. Gynostemium 2. Lamiaceae ii. Cleome gynandra R. Gynobasic style 3. Capparidaceae iii. Calotropis procera S. Gynophore 4. Asclepiadaceae iv. Vanilla planifolia (A) P-2-i, Q-3-iii, R-4-ii, S-1-iv (B) P-3-ii, Q-4-I, R-2-iii, S-1-iv (C) P-4-iii, Q-1-iv, R-2-i, S-3-ii (D) P-4-ii, Q-2-iii, R-1-iv, S-3-i

Families and Plant Species Explained

49. Match the plant products with their sources and the plant parts from which they are obtained. Product Source Plant part P. Annatto 1. Acacia catechu i. Seed Q. Cutch 2. Rubia tinctorum ii. Leaf R. Henna 3. Bixa orellana iii. Root S. Alizarin 4. Lawsonia inermis iv. Stem (A) P-3-ii, Q-4-i, R-2-iii, S-1-iv (B) P-3-i, Q-1-iv, R-4-ii, S-2-iii (C) P-2-ii, Q-1-iii, R-4-iv, S-3-i (D) P-4-ii, Q-3-iv, R-1-iii, S-2-i

Plant Products Matching Quiz

48. Match the name of the diseases with their causal organisms. Disease Causal Organism P. Loose smut of wheat 1. Cercospora personata Q. Wart disease of potato 2. Alternaria solani R. Panama disease of banana 3. Synchytrium endobioticum S. Tikka disease of groundnut 4. Ustilago tritici 5. Fusarium oxysporum 6. Erwinia amylovora (A) P-6, Q-4, R-3, S-2 (B) P-4, Q-6, R-1, S-3 (C) P-4, Q-3, R-5, S-1 (D) P-2, Q-3, R-2, S-6

Matching Plant Diseases to Causal Organisms

47. Identify the CORRECT statements with respect to functioning of ecosystem. P. A food chain is a series of organisms, each one feeding on the organism succeeding it Q. Food web presents a complete picture of the feeding relationships in any given ecosystem R. In ecosystem, energy flows in unidirectional way, whereas nutrients flow in cyclic fashion S. In biogeochemical cycles, nutrients do not alternate between organisms and environment (A) P, Q (B) P, R (C) R, S (D) Q, R

Ecosystem Functioning

46. 𝐴 cross was made between 𝐴𝐴𝐵𝐵𝐶𝐶𝐷𝐷𝐸𝐸 and aabbccddee. The resultants 𝐹1 were selfed. Applying Mendelian principle, PREDICT the proportion of phenotype showing all the recessive characters in F2 generation. (A) 1/64 (B) 1/256 (C) 1/512 (D) 1/1024

Mendelian Genetics

Two Similar Holotypes

44. Which one of the followings is NOT a cryoprotectant for plant tissue? (A) Dimethyl sulfoxide (B) Glycerol (C) Ethylene glycol (D) Liquid nitrogen

Which is NOT a Cryoprotectant for Plant Tissue?

43. A tube like membrane structure that forms the connection between the endoplasmic reticulum of neighboring cells through plasmodesmata is (A) Desmotubule (B) Desmosome (C) Dictyosome (D) Microtubule

Desmotubule in Plasmodesmata

42. Which of the following reduces the transpiration rate when applied to aerial parts of plants? (A) Phosphon-D (B) Paraquat (C) Phenyl mercuric acetate (D) Valinomycin

Which Chemical Reduces Plant Transpiration Rate?

41. Identify the CORRECT family possessing the following characters: presence of glucosinolates, tetradynamous stamens, superior ovary with parietal placentation and siliqua type fruit (A) Brassicaceae (B) Capparidaceae (C) Fumariaceae (D) Papavaraceae

Brassicaceae Family

40. Which of the following techniques is NOT applicable for evaluating the expression of a transgene? (A) Northern blot (B) RT-PCR (C) Western blot (D) Southern blot

Transgene Expression Analysis

39. During fatty acid biosynthesis, the first intermediate malonyl-CoA is formed from (A) Acetyl- CoA and bicarbonate (B) Two acetyl- CoA molecules (C) Acetyl- CoA and biotin (D) Palmitoyl CoA and acyl-carrier protein (ACP)

How Malonyl-CoA Forms in Fatty Acid Biosynthesis

38. Double haploids in plants can be induced by (A) Mitomycin-C (B) Mirin (C) Colchicine (D) 5-Azacytidine

How Double Haploids in Plants Are Induced

Cell Having Cytoplasm but No Nucleus

36. Nuclear membrane is absent in (A) Chlamydomonas (B) Nostoc (C) Volvox (D) Chlorella

Nuclear Membrane Absent in Which Organism

35. Given below are the maps of a 1200 base pairs (bp) long DNA insert and a 3000 bp expression vector. The BamHI(𝐵) and HindIII ( 𝐻 ) restriction sites and DNA length between them are indicated in base pairs. The insert is cloned into the vector at the BamHI site and the desired orientation is shown by the arrow. After cloning, the orientation of the insert in the recombinant plasmid is tested by complete HindIII digestion followed by agarose gel electrophoresis. Which one of the following band patterns reveals the correct orientation of the insert in the construct?

HindIII Digestion to Determine Insert Orientation

$34. A cell suspension was subjected to membrane disruption followed by differential centrifugation to fractionate the cellular components. Match the centrifugal conditions in Column I to the appropriate subcellular components in Column II. Column I Column II P. 1000 g, 10 min i. Microsomes and small vesicles Q. 20000 g, 30 min ii. Ribosomes R. 80000 g, 1 hour iii. Nuclei S. 150000 g, 3 hours iv. Lysosomes and peroxisomes (A) P-iii ; Q-iv ; R-i ; S-ii (B) P-i ; Q-iv ; R-iii ; S-ii (C) P-iii ; Q-iv ; R-ii ; S-i (D) P-ii ; Q-i ; R-iv; S-iii$