Syllabus and Exam Pattern for CSIR NET Life Science Exam 2024
Exam Pattern
The CSIR NET Life Science exam is a computer-based test (CBT) conducted twice a year, in June and December. The exam is divided into three papers:
Paper 1: General Aptitude (Common for all subjects)
- Duration: 2 hours
- Marks: 100
- Number of Questions: 50
- Type of Questions: Multiple Choice Questions (MCQs)
- Syllabus:
- Reasoning and Comprehension: Verbal and Non-Verbal Reasoning, Analytical and Logical Reasoning, Data Interpretation, Comprehension and Critical Reasoning.
- Numerical Ability: Arithmetic, Algebra, Geometry, Statistics, Data Analysis, and Interpretation.
- Research Aptitude: Scientific Methods, Research Ethics, Data Analysis and Interpretation, Communication and Presentation Skills.
- General Science: Current Events in Science and Technology, Environmental Issues, General Awareness.
Paper 2: Life Sciences
- Duration: 3 hours
- Marks: 200
- Number of Questions: 100
- Type of Questions: Multiple Choice Questions (MCQs)
- Syllabus:
- Molecular Biology: Structure and function of biomolecules, DNA replication, transcription, translation, gene regulation, genetic code, mutations, recombination, DNA repair, gene cloning, recombinant DNA technology, transgenic organisms, gene therapy, genomics, proteomics.
- Cell Biology: Cell structure and function, cell cycle, cell signaling, cell differentiation, apoptosis, cancer biology.
- Biochemistry: Enzymes, metabolism, bioenergetics, carbohydrates, lipids, proteins, nucleic acids, vitamins, hormones, biomembranes.
- Plant Physiology: Photosynthesis, respiration, transport, plant growth regulators, stress physiology, plant development.
- Animal Physiology: Digestion, respiration, circulation, excretion, nervous system, endocrine system, reproduction.
- Ecology and Evolution: Ecosystem structure and function, biodiversity, population dynamics, community ecology, ecological succession, evolution, speciation, phylogeny.
- Microbiology: Microbial diversity, microbial metabolism, microbial genetics, virology, immunology, applied microbiology.
- Developmental Biology: Embryonic development, organogenesis, developmental genetics, stem cells, regeneration.
- Biotechnology: Recombinant DNA technology, gene cloning, transgenic organisms, gene therapy, bioinformatics, biopharmaceuticals.
- Environmental Biology: Environmental pollution, conservation biology, climate change, biodiversity conservation.
Paper 3: Life Sciences (Optional)
- Duration: 3 hours
- Marks: 200
- Number of Questions: 100
- Type of Questions: Multiple Choice Questions (MCQs)
- Syllabus:
- Advanced topics in Molecular Biology, Cell Biology, Biochemistry, Plant Physiology, Animal Physiology, Ecology and Evolution, Microbiology, Developmental Biology, Biotechnology, Environmental Biology.
Syllabus in Detail
Molecular Biology
- Structure and function of biomolecules:
- Nucleic acids: DNA, RNA, their structure, properties, and functions.
- Proteins: Amino acids, protein structure, folding, and function.
- Carbohydrates: Monosaccharides, disaccharides, polysaccharides, their structure, properties, and functions.
- Lipids: Fatty acids, triglycerides, phospholipids, steroids, their structure, properties, and functions.
- DNA replication: Mechanism of DNA replication, enzymes involved, replication origin, replication fork, leading and lagging strand synthesis, proofreading and repair mechanisms.
- Transcription: Mechanism of transcription, RNA polymerase, promoters, enhancers, transcription factors, mRNA processing, splicing, capping, polyadenylation.
- Translation: Mechanism of translation, ribosomes, tRNA, mRNA, initiation, elongation, termination, protein folding, post-translational modifications.
- Gene regulation: Operon model, gene regulation in prokaryotes and eukaryotes, transcription factors, regulatory elements, epigenetic modifications.
- Genetic code: Structure and properties of the genetic code, codons, anticodons, wobble hypothesis, mutations.
- Mutations: Types of mutations, spontaneous and induced mutations, mutagens, DNA repair mechanisms.
- Recombination: Homologous recombination, site-specific recombination, transposition.
- DNA repair: Mechanisms of DNA repair, mismatch repair, base excision repair, nucleotide excision repair, double-strand break repair.
- Gene cloning: Restriction enzymes, vectors, cloning strategies, library construction, expression vectors.
- Recombinant DNA technology: Applications of recombinant DNA technology in medicine, agriculture, and industry.
- Transgenic organisms: Production and applications of transgenic organisms.
- Gene therapy: Principles and applications of gene therapy.
- Genomics: Genome sequencing, gene mapping, functional genomics, comparative genomics.
- Proteomics: Protein identification, protein expression profiling, protein-protein interactions.
Cell Biology
- Cell structure and function:
- Plasma membrane: Structure, composition, and functions of the plasma membrane.
- Cytoplasm: Cytosol, organelles, and their functions.
- Nucleus: Structure, function, and organization of the nucleus.
- Mitochondria: Structure, function, and role in energy production.
- Chloroplasts: Structure, function, and role in photosynthesis.
- Endoplasmic reticulum: Rough and smooth ER, their structure, and functions.
- Golgi apparatus: Structure, function, and role in protein modification and sorting.
- Lysosomes: Structure, function, and role in intracellular digestion.
- Peroxisomes: Structure, function, and role in detoxification.
- Cell cycle: Phases of the cell cycle, regulation of the cell cycle, checkpoints, cell cycle control proteins.
- Cell signaling: Types of cell signaling, signal transduction pathways, second messengers, receptor tyrosine kinases, G protein-coupled receptors.
- Cell differentiation: Mechanisms of cell differentiation, developmental pathways, stem cells.
- Apoptosis: Mechanism of apoptosis, caspases, apoptotic pathways, regulation of apoptosis.
- Cancer biology: Causes of cancer, oncogenes, tumor suppressor genes, cancer therapy.
Biochemistry
- Enzymes: Enzyme kinetics, enzyme mechanisms, enzyme regulation, enzyme inhibitors, coenzymes, vitamins.
- Metabolism:
- Carbohydrate metabolism: Glycolysis, gluconeogenesis, glycogen metabolism, pentose phosphate pathway.
- Lipid metabolism: Fatty acid synthesis, fatty acid oxidation, cholesterol metabolism.
- Protein metabolism: Protein synthesis, protein degradation, amino acid metabolism.
- Nucleic acid metabolism: DNA replication, transcription, translation, DNA repair.
- Bioenergetics: Thermodynamics, free energy, ATP, electron transport chain, oxidative phosphorylation.
- Carbohydrates: Monosaccharides, disaccharides, polysaccharides, their structure, properties, and functions.
- Lipids: Fatty acids, triglycerides, phospholipids, steroids, their structure, properties, and functions.
- Proteins: Amino acids, protein structure, folding, and function.
- Nucleic acids: DNA, RNA, their structure, properties, and functions.
- Vitamins: Structure, function, and deficiency diseases of vitamins.
- Hormones: Types of hormones, hormone action, hormone receptors, endocrine system.
- Biomembranes: Structure, composition, and functions of biomembranes.
Plant Physiology
- Photosynthesis: Light-dependent reactions, light-independent reactions, Calvin cycle, photorespiration, C4 photosynthesis, CAM photosynthesis.
- Respiration: Glycolysis, Krebs cycle, electron transport chain, oxidative phosphorylation.
- Transport: Water potential, osmosis, diffusion, active transport, phloem transport, xylem transport.
- Plant growth regulators: Auxins, gibberellins, cytokinins, abscisic acid, ethylene, their biosynthesis, and functions.
- Stress physiology: Drought stress, salinity stress, temperature stress, heavy metal stress, plant responses to stress.
- Plant development: Seed germination, vegetative growth, flowering, fruit development, senescence.
Animal Physiology
- Digestion: Digestive system, digestive enzymes, digestion of carbohydrates, proteins, and lipids, absorption of nutrients.
- Respiration: Respiratory system, gas exchange, oxygen transport, carbon dioxide transport.
- Circulation: Cardiovascular system, blood, heart, blood vessels, blood pressure, blood clotting.
- Excretion: Excretory system, kidney, urine formation, nitrogenous waste excretion.
- Nervous system: Structure and function of the nervous system, neurons, synapses, neurotransmitters, sensory receptors, motor neurons.
- Endocrine system: Hormones, endocrine glands, hormone action, hormone receptors, feedback mechanisms.
- Reproduction: Male and female reproductive systems, gametogenesis, fertilization, pregnancy, development.
Ecology and Evolution
- Ecosystem structure and function: Trophic levels, food chains, food webs, energy flow, nutrient cycling, ecological pyramids.
- Biodiversity: Species diversity, genetic diversity, ecosystem diversity, conservation of biodiversity.
- Population dynamics: Population growth, population regulation, carrying capacity, life history strategies.
- Community ecology: Interspecific interactions, competition, predation, mutualism, commensalism, parasitism, community structure, succession.
- Ecological succession: Primary succession, secondary succession, climax community.
- Evolution: Darwin’s theory of evolution, natural selection, genetic drift, gene flow, speciation.
- Speciation: Allopatric speciation, sympatric speciation, adaptive radiation.
- Phylogeny: Phylogenetic trees, molecular phylogeny, cladistics.
Microbiology
- Microbial diversity: Bacteria, archaea, fungi, viruses, protists, their morphology, physiology, and ecology.
- Microbial metabolism: Photosynthesis, respiration, fermentation, nitrogen fixation, sulfur metabolism.
- Microbial genetics: Bacterial genome, gene transfer, transformation, transduction, conjugation.
- Virology: Structure, replication, and pathogenesis of viruses.
- Immunology: Immune system, innate immunity, adaptive immunity, antibodies, antigens, vaccines, immunodeficiency diseases.
- Applied microbiology: Industrial microbiology, biotechnology, medical microbiology, environmental microbiology.
Developmental Biology
- Embryonic development: Fertilization, cleavage, gastrulation, organogenesis.
- Organogenesis: Development of major organs and systems.
- Developmental genetics: Genes involved in development, homeotic genes, signaling pathways.
- Stem cells: Types of stem cells, properties of stem cells, applications of stem cells.
- Regeneration: Mechanisms of regeneration, regeneration in different organisms.
Biotechnology
- Recombinant DNA technology: Restriction enzymes, vectors, cloning strategies, library construction, expression vectors.
- Gene cloning: Techniques for gene cloning, applications of gene cloning.
- Transgenic organisms: Production and applications of transgenic organisms.
- Gene therapy: Principles and applications of gene therapy.
- Bioinformatics: Sequence analysis, database searching, phylogenetic analysis, gene expression analysis.
- Biopharmaceuticals: Production and applications of biopharmaceuticals.
Environmental Biology
- Environmental pollution: Air pollution, water pollution, soil pollution, noise pollution, their causes, effects, and control measures.
- Conservation biology: Biodiversity conservation, habitat conservation, species conservation, endangered species.
- Climate change: Causes of climate change, effects of climate change, mitigation and adaptation strategies.
- Biodiversity conservation: Importance of biodiversity, threats to biodiversity, conservation strategies.
Exam Preparation Tips
- Understand the syllabus thoroughly: Go through the detailed syllabus and identify the important topics.
- Refer to standard textbooks and study materials: Use recommended textbooks and study materials to gain a comprehensive understanding of the concepts.
- Practice previous years’ question papers: Solving previous years’ question papers will help you understand the exam pattern, difficulty level, and important topics.
- Join online courses or coaching classes: Online courses and coaching classes can provide structured learning and expert guidance.
- Develop effective study habits: Create a study schedule, set realistic goals, and take regular breaks to avoid burnout.
- Focus on understanding concepts: Don’t just memorize facts, try to understand the underlying concepts.
- Practice mock tests: Take mock tests regularly to assess your preparation level and identify areas that need improvement.
- Stay updated with current trends in Life Sciences: Read scientific journals and articles to stay updated with the latest advancements in the field.
Important Books for CSIR NET Life Science Exam
- Molecular Biology:
- Molecular Biology of the Gene by James D. Watson
- Principles of Genetics by D. Peter Snustad and Michael J. Simmons
- Genes VIII by Benjamin Lewin
- Cell Biology:
- Molecular Biology of the Cell by Bruce Alberts
- Essential Cell Biology by Bruce Alberts
- Lehninger Principles of Biochemistry by David L. Nelson and Michael M. Cox
- Biochemistry:
- Lehninger Principles of Biochemistry by David L. Nelson and Michael M. Cox
- Biochemistry by Voet and Voet
- Biochemistry by Stryer
- Plant Physiology:
- Plant Physiology by Lincoln Taiz and Eduardo Zeiger
- Plant Physiology by Salisbury and Ross
- Principles of Plant Physiology by Hopkins and Hüner
- Animal Physiology:
- Animal Physiology by Hill, Wyse, and Anderson
- Principles of Animal Physiology by Schmidt-Nielsen
- Human Physiology by Guyton and Hall
- Ecology and Evolution:
- Ecology by E. P. Odum
- Evolutionary Biology by Douglas Futuyma
- Principles of Ecology by Smith and Smith
- Microbiology:
- Brock Biology of Microorganisms by Madigan, Martinko, Bender, Buckley, and Stahl
- Microbiology by Prescott, Harley, and Klein
- Microbiology: An Introduction by Tortora, Funke, and Case
- Developmental Biology:
- Principles of Development by Lewis Wolpert
- Developmental Biology by Gilbert
- Essential Developmental Biology by Scott F. Gilbert
- Biotechnology:
- Principles of Gene Manipulation and Genomics by Primrose and Twyman
- Biotechnology by B. D. Singh
- Biotechnology: A Textbook of Industrial Microbiology by A. K. Srivastava
- Environmental Biology:
- Environmental Biology by Miller and Spoolman
- Environmental Science by G. Tyler Miller
- Ecology and Environment by P. D. Sharma
Important Websites for CSIR NET Life Science Exam
- CSIR NET Website: https://csirnet.nta.nic.in/
- National Testing Agency (NTA) Website: https://nta.ac.in/
- JRF and SRF: https://www.csir.res.in/
- Life Science Journals:
- Nature: https://www.nature.com/
- Science: https://www.sciencemag.org/
- Cell: https://www.cell.com/
- PNAS: https://www.pnas.org/
- Online Study Resources:
- Khan Academy: https://www.khanacademy.org/
- Coursera: https://www.coursera.org/
- EdX: https://www.edx.org/
- Udemy: https://www.udemy.com/
CSIR NET Life Science Exam Scorecard
The CSIR NET Life Science exam scorecard is released by the NTA on the official website. The scorecard contains the following information:
- Candidate’s Name:
- Roll Number:
- Application Number:
- Category:
- Exam Date:
- Paper 1 Score:
- Paper 2 Score:
- Paper 3 Score (if applicable):
- Overall Score:
- Rank:
- Qualifying Status:
The scorecard is valid for two years from the date of declaration of the result.
CSIR NET Life Science Exam Cut-off
The CSIR NET Life Science exam cut-off is the minimum score required to qualify for the JRF or SRF. The cut-off varies every year depending on the difficulty level of the exam, the number of candidates, and the number of vacancies.
Table 1: CSIR NET Life Science Exam Cut-off for Previous Years
Year | General | OBC | SC | ST |
---|---|---|---|---|
2023 | 60 | 55 | 50 | 45 |
2022 | 65 | 60 | 55 | 50 |
2021 | 70 | 65 | 60 | 55 |
Note: The cut-off scores mentioned above are for illustrative purposes only and may vary from year to year.
CSIR NET Life Science Exam Eligibility Criteria
- Nationality: Indian citizen
- Educational Qualification:
- JRF: Master’s degree in Life Sciences or equivalent with at least 55% marks (50% for SC/ST/PwD candidates).
- SRF: Master’s degree in Life Sciences or equivalent with at least 55% marks (50% for SC/ST/PwD candidates) and a valid CSIR NET score.
- Age Limit:
- JRF: Maximum 28 years (relaxation for reserved categories).
- SRF: No age limit.
CSIR NET Life Science Exam Application Process
- Online Application: The application process is entirely online. Candidates need to visit the NTA website and fill out the application form.
- Application Fee: The application fee is INR 1000 for General and OBC candidates and INR 500 for SC/ST/PwD candidates.
- Payment Mode: The application fee can be paid online through debit card, credit card, net banking, or UPI.
- Important Dates: The important dates for the CSIR NET Life Science exam are announced by the NTA on the official website.
CSIR NET Life Science Exam Admit Card
The CSIR NET Life Science exam admit card is released by the NTA on the official website. Candidates need to download the admit card and carry it to the exam center. The admit card contains the following information:
- Candidate’s Name:
- Roll Number:
- Application Number:
- Exam Date:
- Exam Time:
- Exam Center:
- Instructions for Candidates:
Table 2: CSIR NET Life Science Exam Admit Card Important Dates
Year | Admit Card Release Date |
---|---|
2023 | 15th May |
2022 | 10th May |
2021 | 5th May |
Note: The admit card release dates mentioned above are for illustrative purposes only and may vary from year to year.
CSIR NET Life Science Exam Result
The CSIR NET Life Science exam result is declared by the NTA on the official website. The result contains the following information:
- Candidate’s Name:
- Roll Number:
- Application Number:
- Category:
- Paper 1 Score:
- Paper 2 Score:
- Paper 3 Score (if applicable):
- Overall Score:
- Rank:
- Qualifying Status:
The result is usually declared within 6-8 weeks after the exam.
CSIR NET Life Science Exam FAQs
- What is the syllabus for the CSIR NET Life Science exam?
- The syllabus for the CSIR NET Life Science exam is comprehensive and covers all major areas of Life Sciences.
- What is the exam pattern for the CSIR NET Life Science exam?
- The CSIR NET Life Science exam is a computer-based test (CBT) conducted twice a year, in June and December. The exam is divided into three papers: Paper 1 (General Aptitude), Paper 2 (Life Sciences), and Paper 3 (Life Sciences – Optional).
- What are the eligibility criteria for the CSIR NET Life Science exam?
- The eligibility criteria for the CSIR NET Life Science exam include nationality, educational qualification, and age limit.
- How can I apply for the CSIR NET Life Science exam?
- The application process for the CSIR NET Life Science exam is entirely online. Candidates need to visit the NTA website and fill out the application form.
- What is the application fee for the CSIR NET Life Science exam?
- The application fee for the CSIR NET Life Science exam is INR 1000 for General and OBC candidates and INR 500 for SC/ST/PwD candidates.
- How can I prepare for the CSIR NET Life Science exam?
- To prepare for the CSIR NET Life Science exam, candidates should understand the syllabus thoroughly, refer to standard textbooks and study materials, practice previous years’ question papers, join online courses or coaching classes, develop effective study habits, focus on understanding concepts, practice mock tests, and stay updated with current trends in Life Sciences.
- What are the important books for the CSIR NET Life Science exam?
- There are many important books for the CSIR NET Life Science exam, including Molecular Biology of the Gene by James D. Watson, Principles of Genetics by D. Peter Snustad and Michael J. Simmons, Genes VIII by Benjamin Lewin, Molecular Biology of the Cell by Bruce Alberts, Essential Cell Biology by Bruce Alberts, Lehninger Principles of Biochemistry by David L. Nelson and Michael M. Cox, Plant Physiology by Lincoln Taiz and Eduardo Zeiger, Animal Physiology by Hill, Wyse, and Anderson, Ecology by E. P. Odum, Evolutionary Biology by Douglas Futuyma, Brock Biology of Microorganisms by Madigan, Martinko, Bender, Buckley, and Stahl, Principles of Development by Lewis Wolpert, Principles of Gene Manipulation and Genomics by Primrose and Twyman, Environmental Biology by Miller and Spoolman, and many others.
- What are the important websites for the CSIR NET Life Science exam?
- The important websites for the CSIR NET Life Science exam include the CSIR NET website, the National Testing Agency (NTA) website, JRF and SRF, and various Life Science journals and online study resources.
- What is the CSIR NET Life Science exam scorecard?
- The CSIR NET Life Science exam scorecard is released by the NTA on the official website. The scorecard contains the candidate’s name, roll number, application number, category, exam date, paper 1 score, paper 2 score, paper 3 score (if applicable), overall score, rank, and qualifying status.
- What is the CSIR NET Life Science exam cut-off?
- The CSIR NET Life Science exam cut-off is the minimum score required to qualify for the JRF or SRF. The cut-off varies every year depending on the difficulty level of the exam, the number of candidates, and the number of vacancies.
- What is the CSIR NET Life Science exam admit card?
- The CSIR NET Life Science exam admit card is released by the NTA on the official website. Candidates need to download the admit card and carry it to the exam center. The admit card contains the candidate’s name, roll number, application number, exam date, exam time, exam center, and instructions for candidates.
- What is the CSIR NET Life Science exam result?
- The CSIR NET Life Science exam result is declared by the NTA on the official website. The result contains the candidate’s name, roll number, application number, category, paper 1 score, paper 2 score, paper 3 score (if applicable), overall score, rank, and qualifying status.
- When is the CSIR NET Life Science exam result declared?
- The CSIR NET Life Science exam result is usually declared within 6-8 weeks after the exam.
CSIR NET Life Science Exam Preparation Tips
- Understand the syllabus thoroughly: Go through the detailed syllabus and identify the important topics.
- Refer to standard textbooks and study materials: Use recommended textbooks and study materials to gain a comprehensive understanding of the concepts.
- Practice previous years’ question papers: Solving previous years’ question papers will help you understand the exam pattern, difficulty level, and important topics.
- Join online courses or coaching classes: Online courses and coaching classes can provide structured learning and expert guidance.
- Develop effective study habits: Create a study schedule, set realistic goals, and take regular breaks to avoid burnout.
- Focus on understanding concepts: Don’t just memorize facts, try to understand the underlying concepts.
- Practice mock tests: Take mock tests regularly to assess your preparation level and identify areas that need improvement.
- Stay updated with current trends in Life Sciences: Read scientific journals and articles to stay updated with the latest advancements in the field.
CSIR NET Life Science Exam Conclusion
The CSIR NET Life Science exam is a challenging but rewarding exam that can open doors to a career in research and teaching. By following the tips and strategies outlined above, candidates can increase their chances of success in the exam.
Frequently Asked Questions (FAQs) and Short Answers:
General:
- What is the exam pattern for this exam?
- It’s a computer-based test (CBT) with three papers: Paper 1 (General Aptitude), Paper 2 (Subject-specific), and Paper 3 (Optional, subject-specific).
- When is the exam conducted?
- Twice a year, usually in June and December.
- What is the duration of the exam?
- Paper 1: 2 hours, Paper 2 & 3: 3 hours each.
- What is the syllabus for the exam?
- It covers a wide range of topics in Life Sciences, including Molecular Biology, Cell Biology, Biochemistry, Plant Physiology, Animal Physiology, Ecology and Evolution, Microbiology, Developmental Biology, Biotechnology, and Environmental Biology.
- What is the eligibility criteria for the exam?
- You need to have a Master’s degree in Life Sciences or equivalent with a minimum percentage of marks (varies for different categories).
- How can I apply for the exam?
- The application process is entirely online through the official website of the National Testing Agency (NTA).
- What is the application fee?
- The fee varies for different categories (General, OBC, SC, ST, PwD).
- How can I prepare for the exam?
- Focus on understanding the syllabus, refer to standard textbooks, practice previous years’ papers, join online courses or coaching classes, and stay updated with current trends in Life Sciences.
Exam-Specific:
- What is the marking scheme for the exam?
- Each correct answer carries 2 marks, and there is a negative marking of 0.5 marks for each incorrect answer.
- How many questions are there in each paper?
- Paper 1: 50 questions, Paper 2 & 3: 100 questions each.
- What are the important topics to focus on?
- The syllabus is vast, but some frequently asked topics include DNA replication, transcription, translation, cell signaling, metabolism, photosynthesis, respiration, evolution, and ecology.
- What are some good books for preparation?
- There are many recommended books, including Lehninger Principles of Biochemistry, Molecular Biology of the Cell, Genetics by Snustad and Simmons, and Ecology by Odum.
- How can I get the admit card?
- The admit card is available for download from the NTA website after registration.
- What is the cut-off score for qualifying?
- The cut-off varies every year depending on the difficulty level of the exam and the number of candidates.
- What happens after the exam?
- The NTA declares the results online, and candidates who qualify are eligible for Junior Research Fellowship (JRF) or Senior Research Fellowship (SRF).
Other:
- What are the benefits of qualifying the exam?
- It opens doors to research opportunities, teaching positions, and other career paths in the field of Life Sciences.
- What are some career options after qualifying?
- You can pursue research in various fields, become a lecturer in universities or colleges, work in government research organizations, or join the pharmaceutical or biotechnology industry.
- What are the important websites for this exam?
- The official websites of CSIR NET, NTA, and JRF/SRF are crucial resources.
Remember, these are just a few examples. The best way to get specific answers to your questions is to refer to the official website of the CSIR NET exam and other reliable sources.