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Answer first
Biology PYQs (previous year questions) for CDS: Biology (General Knowledge) had 225 questions across the 66 official CDS papers we tagged (2016–2026), and appeared in 22 of them. Asked in 11 of 11 years. The concepts asked in the most papers: Cell Biology, Biomolecules, Human Diseases.
Year-wise question count
Asked in 11 of 11 years, with 2 papers each year.
| Year | Questions |
|---|---|
| CDS 2026 | 26 |
| CDS 2025 | 19 |
| CDS 2024 | 20 |
| CDS 2023 | 20 |
| CDS 2022 | 21 |
| CDS 2021 | 21 |
| CDS 2020 | 19 |
| CDS 2019 | 19 |
| CDS 2018 | 23 |
| CDS 2017 | 16 |
| CDS 2016 | 21 |
Most-asked concepts
Sorted by the number of papers a concept appeared in.
| Concept | Questions | Papers | Years |
|---|---|---|---|
| Cell Biology | 29 | 18 | 2026, 2025, 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016 |
| Biomolecules | 9 | 8 | 2026, 2025, 2024, 2022, 2017, 2016 |
| Human Diseases | 8 | 8 | 2026, 2025, 2018, 2017, 2016 |
| Human Physiology | 11 | 7 | 2024, 2019, 2018, 2017, 2016 |
| Ecology | 9 | 7 | 2026, 2023, 2021, 2019, 2018, 2017, 2016 |
| Human Body | 9 | 6 | 2025, 2022, 2021, 2016 |
| Genetics | 6 | 6 | 2024, 2021, 2020, 2017, 2016 |
| Cell Organelles | 6 | 5 | 2024, 2020, 2019 |
| Plant Nutrition | 5 | 5 | 2024, 2022, 2021, 2018 |
| Plant Physiology | 7 | 4 | 2024, 2023, 2018, 2017 |
| Human Health and Disease | 6 | 4 | 2022, 2021 |
| Plant Tissues | 6 | 4 | 2023, 2021, 2020, 2019 |
| Animal Kingdom | 5 | 4 | 2025, 2021, 2020 |
| Diseases | 4 | 4 | 2024, 2020, 2019 |
| Photosynthesis | 4 | 4 | 2026, 2024, 2023, 2019 |
| Biotechnology | 4 | 3 | 2026, 2022, 2016 |
| Plant Morphology | 4 | 3 | 2024, 2023, 2018 |
| Vitamins | 4 | 3 | 2019, 2017, 2016 |
| Agriculture | 3 | 3 | 2026, 2021, 2016 |
| Animal Tissues | 3 | 3 | 2022, 2018 |
| Enzymes | 3 | 3 | 2025, 2024, 2016 |
| Evolution | 3 | 3 | 2026, 2021, 2020 |
| Plant Hormones | 3 | 3 | 2025, 2024, 2021 |
| Plant Kingdom | 3 | 3 | 2022, 2020, 2019 |
| Plant Reproduction | 3 | 3 | 2023, 2020, 2018 |
| Reproduction | 3 | 3 | 2017, 2016 |
| Animal Classification | 5 | 2 | 2019, 2018 |
| Microorganisms | 4 | 2 | 2022, 2018 |
| Circulatory System | 3 | 2 | 2025, 2023 |
| Human Digestion | 3 | 2 | 2026, 2020 |
| Human Health | 3 | 2 | 2026, 2016 |
| Endocrine System | 2 | 2 | 2023, 2020 |
| Hormones | 2 | 2 | 2016 |
| Human Circulation | 2 | 2 | 2026 |
| Human Eye | 2 | 2 | 2025, 2024 |
| Microbiology | 2 | 2 | 2020, 2017 |
| Nervous System | 2 | 2 | 2025, 2023 |
| Nutrition in Organisms | 2 | 2 | 2023, 2021 |
| Molecular Biology | 2 | 1 | 2017 |
| Plant Adaptations | 2 | 1 | 2024 |
| Animal Physiology | 1 | 1 | 2020 |
| Animal Products | 1 | 1 | 2017 |
| Blood | 1 | 1 | 2025 |
| Cell Division | 1 | 1 | 2026 |
| Cell Transport | 1 | 1 | 2019 |
| Classification | 1 | 1 | 2026 |
| Classification of Organisms | 1 | 1 | 2025 |
| Digestion | 1 | 1 | 2023 |
| Digestive System | 1 | 1 | 2025 |
| Excretory System | 1 | 1 | 2020 |
| Eye Defects | 1 | 1 | 2025 |
| Fauna of India | 1 | 1 | 2019 |
| Heredity | 1 | 1 | 2026 |
| Human Reproduction | 1 | 1 | 2018 |
| Immunity | 1 | 1 | 2024 |
| Immunology | 1 | 1 | 2020 |
| Lipids and Health | 1 | 1 | 2016 |
| Microbes and Antibiotics | 1 | 1 | 2026 |
| Modes of Nutrition | 1 | 1 | 2019 |
| Muscle Fatigue | 1 | 1 | 2023 |
| Nutrition | 1 | 1 | 2017 |
| Osmosis | 1 | 1 | 2023 |
| Plant Anatomy | 1 | 1 | 2024 |
| Plant Biochemistry | 1 | 1 | 2016 |
| Plant Pigments | 1 | 1 | 2026 |
| Reproductive System | 1 | 1 | 2025 |
| Respiration | 1 | 1 | 2025 |
| Taxonomy | 1 | 1 | 2020 |
| Wildlife | 1 | 1 | 2018 |
How to practise Biology PYQs
- Start with the concepts at the top of the table. They have come back the most.
- Solve one year’s Biology questions from the official PDF against the clock, then check the answer listed below.
- Log every miss as a concept gap, a calculation slip or a misread. Each needs a different fix.
- Once a concept is clean in two papers, move to the next. Then sit a full paper from the year pages.
Questions by year
Each line gives the question number and paper, type, concept, our one-line summary and the official answer, with a link to the official PDF.
CDS2026
- Q.1 (CDS (I) GK) · MCQ · Cell Biology: Name of the nucleic-acid region of a prokaryotic cell PDF
- Q.2 (CDS (I) GK) · MCQ · Human Digestion: Enzyme that lets adults digest milk PDF
- Q.3 (CDS (I) GK) · MCQ · Microbes and Antibiotics: Bacterial structure that penicillin targets PDF
- Q.4 (CDS (I) GK) · MCQ · Cell Biology: Cell type with the most lysosomes PDF
- Q.5 (CDS (I) GK) · MCQ · Plant Pigments: Which role is not a function of carotenoids PDF
- Q.6 (CDS (I) GK) · MCQ · Heredity: Which trait of a chess champion is not inherited PDF
- Q.7 (CDS (I) GK) · MCQ · Human Circulation: Heart chamber first receiving oxygenated blood from lungs PDF
- Q.8 (CDS (I) GK) · MCQ · Agriculture: Statements on vermicompost and organic farming PDF
- Q.9 (CDS (I) GK) · MCQ · Cell Biology: Match cell organelles with their functions PDF
- Q.10 (CDS (I) GK) · MCQ · Human Diseases: Mismatched pair of disease and pathogen type PDF
- Q.38 (CDS (II) GK) · MCQ · Ecology: Identify the set that forms a food chain PDF
- Q.106 (CDS (II) GK) · MCQ · Biomolecules: Incorrect statements comparing glycogen and starch PDF
- Q.107 (CDS (II) GK) · MCQ · Cell Biology: Process that does not use active transport PDF
- Q.108 (CDS (II) GK) · MCQ · Cell Division: Incorrect statement about mitosis PDF
- Q.109 (CDS (II) GK) · MCQ · Biomolecules: Protein important for cartilage that is not a globin PDF
- Q.110 (CDS (II) GK) · MCQ · Human Circulation: Activity a mammalian red blood cell cannot perform PDF
- Q.111 (CDS (II) GK) · MCQ · Human Diseases: Statements on malaria transmission PDF
- Q.112 (CDS (II) GK) · MCQ · Photosynthesis: Process involved in the light-independent reactions PDF
- Q.113 (CDS (II) GK) · MCQ · Human Health: Feature associated with schizophrenia PDF
- Q.114 (CDS (II) GK) · MCQ · Cell Biology: Structure not found in a prokaryotic cell PDF
- Q.115 (CDS (II) GK) · MCQ · Evolution: Incorrect statement on Hardy-Weinberg, Darwin and Lamarck PDF
- Q.116 (CDS (II) GK) · MCQ · Ecology: Option linked to mitigating environmental problems PDF
- Q.117 (CDS (II) GK) · MCQ · Biotechnology: Statements on enzymes used in genetic engineering PDF
- Q.118 (CDS (II) GK) · MCQ · Biotechnology: Which organism is not a biocontrol agent PDF
- Q.119 (CDS (II) GK) · MCQ · Classification: Incorrect statement on protists and fungi PDF
- Q.120 (CDS (II) GK) · MCQ · Human Health: Statements on causes and spread of cancer PDF
CDS2025
- Q.71 (CDS (I) GK) · MCQ · Circulatory System: Instrument for measuring blood pressure manually PDF
- Q.72 (CDS (I) GK) · MCQ · Eye Defects: Other name for myopia PDF
- Q.73 (CDS (I) GK) · MCQ · Cell Biology: Why rough endoplasmic reticulum looks rough PDF
- Q.74 (CDS (I) GK) · MCQ · Plant Hormones: Which is not a plant hormone PDF
- Q.75 (CDS (I) GK) · MCQ · Circulatory System: Normal systolic pressure in humans PDF
- Q.76 (CDS (I) GK) · MCQ · Animal Kingdom: Phylum of sponges PDF
- Q.77 (CDS (I) GK) · MCQ · Biomolecules: Components of lactose PDF
- Q.78 (CDS (I) GK) · MCQ · Enzymes: Name for enzymes catalysing the same reaction with different structure PDF
- Q.79 (CDS (I) GK) · MCQ · Respiration: Number of carbon atoms in pyruvate PDF
- Q.80 (CDS (I) GK) · MCQ · Human Eye: Point on the retina lacking photoreceptors PDF
- Q.41 (CDS (II) GK) · MCQ · Classification of Organisms: Correct hierarchy for classifying animals (official answer: D) PDF
- Q.42 (CDS (II) GK) · MCQ · Human Diseases: Example of an airborne disease (official answer: A) PDF
- Q.43 (CDS (II) GK) · MCQ · Blood: Four blood types in ABO typing (official answer: B) PDF
- Q.44 (CDS (II) GK) · MCQ · Reproductive System: Organ not part of the male reproductive system (official answer: C) PDF
- Q.45 (CDS (II) GK) · MCQ · Nervous System: Parts of the human brain (official answer: C) PDF
- Q.46 (CDS (II) GK) · MCQ · Human Body: Composition of tooth enamel (official answer: A) PDF
- Q.47 (CDS (II) GK) · MCQ · Digestive System: Finger-like projections lining the small intestine (official answer: B) PDF
- Q.48 (CDS (II) GK) · MCQ · Biomolecules: Which sugars are disaccharides (official answer: C) PDF
- Q.49 (CDS (II) GK) · MCQ · Cell Biology: Organelle found in a prokaryotic cell (official answer: C) PDF
CDS2024
- Q.12 (CDS (I) GK) · MCQ · Genetics: What the famous image Photo 51 shows (official answer: B) PDF
- Q.23 (CDS (I) GK) · MCQ · Immunity: Statements on how vaccination protects against infection (official answer: C) PDF
- Q.24 (CDS (I) GK) · MCQ · Cell Biology: Human cells that lack a nucleus (official answer: C) PDF
- Q.26 (CDS (I) GK) · MCQ · Cell Organelles: What microbodies in plant and animal cells contain (official answer: B) PDF
- Q.27 (CDS (I) GK) · MCQ · Enzymes: Antibacterial enzyme found in saliva and tears (official answer: C) PDF
- Q.28 (CDS (I) GK) · MCQ · Plant Morphology: Set of vegetables that are underground stems (official answer: C) PDF
- Q.62 (CDS (I) GK) · MCQ · Diseases: Category of virus that causes dengue (official answer: A) PDF
- Q.63 (CDS (I) GK) · MCQ · Human Physiology: Source of blood clotting factors (official answer: C) PDF
- Q.64 (CDS (I) GK) · MCQ · Human Physiology: What causes the pulse (official answer: C) PDF
- Q.65 (CDS (I) GK) · MCQ · Biomolecules: What denatures when egg white turns solid on heating (official answer: B) PDF
- Q.1 (CDS (II) GK) · MCQ · Plant Nutrition: Element that is not a micronutrient for plants PDF
- Q.2 (CDS (II) GK) · MCQ · Plant Physiology: What xylem transports in plants PDF
- Q.3 (CDS (II) GK) · MCQ · Plant Hormones: Plant hormone that inhibits growth PDF
- Q.4 (CDS (II) GK) · MCQ · Biomolecules: Biomolecule category to which starch belongs PDF
- Q.5 (CDS (II) GK) · MCQ · Plant Adaptations: Feature that is not seen in xerophytes PDF
- Q.6 (CDS (II) GK) · MCQ · Plant Adaptations: Type of soil on which halophytes grow PDF
- Q.7 (CDS (II) GK) · MCQ · Plant Anatomy: Item that is not part of a vascular bundle PDF
- Q.9 (CDS (II) GK) · MCQ · Cell Organelles: Animal cell organelle that digests foreign material PDF
- Q.10 (CDS (II) GK) · MCQ · Photosynthesis: Leaf structure that holds chlorophyll PDF
- Q.27 (CDS (II) GK) · MCQ · Human Eye: Statements on presbyopia and its correction PDF
CDS2023
- Q.1 (CDS (I) GK) · MCQ · Muscle Fatigue: Cause of cramps in a sprinter's thigh muscles after a run (official answer: A) PDF
- Q.2 (CDS (I) GK) · MCQ · Photosynthesis: Colour of a sunlit leaf after the starch-iodine test (official answer: C) PDF
- Q.3 (CDS (I) GK) · MCQ · Osmosis: Effect on RBCs placed in isotonic normal saline (official answer: D) PDF
- Q.4 (CDS (I) GK) · MCQ · Digestion: Incorrect statement about bile secreted by the liver (official answer: A) PDF
- Q.5 (CDS (I) GK) · MCQ · Circulatory System: What the two numbers in a 120/80 mmHg blood pressure denote (official answer: A) PDF
- Q.39 (CDS (I) GK) · MCQ · Nervous System: Correct sequence of components in a reflex arc (official answer: A) PDF
- Q.40 (CDS (I) GK) · MCQ · Endocrine System: Element essential for the thyroid to make thyroxine (official answer: D) PDF
- Q.41 (CDS (I) GK) · MCQ · Cell Biology: Locations of RNA in plant cells (official answer: D) PDF
- Q.42 (CDS (I) GK) · MCQ · Plant Tissues: Location of intercalary meristem in grasses (official answer: C) PDF
- Q.43 (CDS (I) GK) · MCQ · Plant Tissues: Xylem element made of living cells (official answer: C) PDF
- Q.11 (CDS (II) GK) · MCQ · Plant Morphology: What the term phyllotaxy refers to (official answer: A) PDF
- Q.12 (CDS (II) GK) · MCQ · Cell Biology: Components of chromosomes besides DNA (official answer: C) PDF
- Q.13 (CDS (II) GK) · MCQ · Cell Biology: Name of the bacterial nuclear region without membrane (official answer: D) PDF
- Q.14 (CDS (II) GK) · MCQ · Cell Biology: Labelling organelles in a plant cell diagram (official answer: C) PDF
- Q.44 (CDS (II) GK) · MCQ · Cell Biology: Correct match of cell organelles with functions (official answer: A) PDF
- Q.45 (CDS (II) GK) · MCQ · Cell Biology: Organism lacking a cell wall (official answer: D) PDF
- Q.46 (CDS (II) GK) · MCQ · Plant Physiology: Forces behind upward water movement in xylem (official answer: B) PDF
- Q.47 (CDS (II) GK) · MCQ · Ecology: Direction of energy and nutrient flow in an ecosystem (official answer: B) PDF
- Q.48 (CDS (II) GK) · MCQ · Nutrition in Organisms: Which organism is a saprophyte (official answer: B) PDF
- Q.49 (CDS (II) GK) · MCQ · Plant Reproduction: Cell in an angiosperm ovule that is not haploid (official answer: A) PDF
CDS2022
- Q.14 (CDS (I) GK) · MCQ · Biotechnology: Incorrect statement about genetically modified organisms (official answer: B) PDF
- Q.15 (CDS (I) GK) · MCQ · Animal Tissues: Tissue lining the mouth and oesophagus (official answer: C) PDF
- Q.16 (CDS (I) GK) · MCQ · Cell Biology: Correct statement about the cell membrane (official answer: C) PDF
- Q.17 (CDS (I) GK) · MCQ · Plant Nutrition: Process by which plants make glucose (official answer: B) PDF
- Q.18 (CDS (I) GK) · MCQ · Human Health and Disease: Vitamin deficiency causing rickets (official answer: B) PDF
- Q.19 (CDS (I) GK) · MCQ · Human Body: Match blood vessels with their functions (official answer: A) PDF
- Q.25 (CDS (I) GK) · MCQ · Human Body: Mineral acid present in the human stomach (official answer: A) PDF
- Q.26 (CDS (I) GK) · MCQ · Plant Kingdom: Organism from which litmus is obtained (official answer: C) PDF
- Q.28 (CDS (I) GK) · MCQ · Microorganisms: What change causes mutation in a virus (official answer: B) PDF
- Q.29 (CDS (I) GK) · MCQ · Microorganisms: Group to which yeast belongs (official answer: B) PDF
- Q.30 (CDS (I) GK) · MCQ · Microorganisms: What hyphae are (official answer: B) PDF
- Q.17 (CDS (II) GK) · MCQ · Cell Biology: Membranes around nucleus and chloroplasts in plant cells (official answer: B) PDF
- Q.18 (CDS (II) GK) · MCQ · Biomolecules: Correct statement about starch and glycogen (official answer: C) PDF
- Q.19 (CDS (II) GK) · MCQ · Plant Nutrition: Correct statement on the process of photosynthesis (official answer: D) PDF
- Q.20 (CDS (II) GK) · MCQ · Human Health and Disease: Deficiency causing kwashiorkor (official answer: D) PDF
- Q.21 (CDS (II) GK) · MCQ · Human Body: Enzyme pair that does not work at acidic pH (official answer: C) PDF
- Q.22 (CDS (II) GK) · MCQ · Human Body: Metabolism that produces urea (official answer: A) PDF
- Q.23 (CDS (II) GK) · MCQ · Human Health and Disease: Disease caused by iron deficiency (official answer: A) PDF
- Q.69 (CDS (II) GK) · MCQ · Animal Tissues: Tissue that stores fat in the body (official answer: A) PDF
- Q.70 (CDS (II) GK) · MCQ · Cell Biology: Feature of the cell membrane structure (official answer: A) PDF
- Q.71 (CDS (II) GK) · MCQ · Human Body: Longest part of the alimentary canal (official answer: B) PDF
CDS2021
- Q.91 (CDS (I) GK) · MCQ · Cell Biology: Cells that lack a cell wall (official answer: D) PDF
- Q.92 (CDS (I) GK) · MCQ · Genetics: How to check the parentage of a tall plant (official answer: B) PDF
- Q.93 (CDS (I) GK) · MCQ · Plant Hormones: Plant hormone that promotes cell division (official answer: C) PDF
- Q.94 (CDS (I) GK) · MCQ · Cell Biology: Cell organelles having their own DNA and ribosomes (official answer: B) PDF
- Q.95 (CDS (I) GK) · MCQ · Cell Biology: Correct definition of osmosis (official answer: D) PDF
- Q.96 (CDS (I) GK) · MCQ · Agriculture: Term for growing crops together in a definite pattern (official answer: B) PDF
- Q.109 (CDS (I) GK) · MCQ · Human Health and Disease: Why antibiotics do not work against viruses (official answer: D) PDF
- Q.110 (CDS (I) GK) · MCQ · Human Health and Disease: Cause of sleeping sickness (official answer: A) PDF
- Q.111 (CDS (I) GK) · MCQ · Animal Kingdom: Identify the free-living animal (official answer: D) PDF
- Q.112 (CDS (I) GK) · MCQ · Human Body: Structure of a cardiac muscle cell (official answer: D) PDF
- Q.13 (CDS (II) GK) · MCQ · Ecology: What limits the number of trophic levels (official answer: C) PDF
- Q.14 (CDS (II) GK) · MCQ · Genetics: Ratio of pure tall to short plants in a pea cross (official answer: A) PDF
- Q.15 (CDS (II) GK) · MCQ · Evolution: Incorrect statement about variations (official answer: B) PDF
- Q.16 (CDS (II) GK) · MCQ · Ecology: Best description of a population (official answer: A) PDF
- Q.17 (CDS (II) GK) · MCQ · Human Body: Correct statement on double circulation of blood (official answer: A) PDF
- Q.18 (CDS (II) GK) · MCQ · Nutrition in Organisms: Organisms that digest food outside the body (official answer: A) PDF
- Q.27 (CDS (II) GK) · MCQ · Plant Nutrition: Nutrient usually missing from fertilisers (official answer: A) PDF
- Q.28 (CDS (II) GK) · MCQ · Animal Kingdom: Feature confirming an animal is an insect (official answer: A) PDF
- Q.29 (CDS (II) GK) · MCQ · Animal Kingdom: Group of marine chordates without a vertebral column (official answer: B) PDF
- Q.30 (CDS (II) GK) · MCQ · Plant Tissues: Location of intercalary meristem (official answer: A) PDF
- Q.97 (CDS (II) GK) · MCQ · Human Health and Disease: Term for infection maintained at a baseline level (official answer: A) PDF
CDS2020
- Q.5 (CDS (I) GK) · MCQ · Human Digestion: Acid produced in the human stomach (official answer: D) PDF
- Q.14 (CDS (I) GK) · MCQ · Diseases: Disease that is not epidemic (official answer: D) PDF
- Q.15 (CDS (I) GK) · MCQ · Animal Physiology: Animal with a three-chambered heart (official answer: B) PDF
- Q.16 (CDS (I) GK) · MCQ · Plant Reproduction: Order of events in sexual reproduction in plants (official answer: C) PDF
- Q.18 (CDS (I) GK) · MCQ · Cell Biology: Energy currency of cells (official answer: B) PDF
- Q.19 (CDS (I) GK) · MCQ · Human Digestion: First enzyme to mix with food in the gut (official answer: D) PDF
- Q.27 (CDS (I) GK) · MCQ · Excretory System: Order of organs in the path of urine (official answer: A) PDF
- Q.28 (CDS (I) GK) · MCQ · Endocrine System: Endocrine gland that is not paired (official answer: B) PDF
- Q.29 (CDS (I) GK) · MCQ · Cell Organelles: Organelle that contains DNA (official answer: B) PDF
- Q.30 (CDS (I) GK) · MCQ · Immunology: Scientist who introduced immunisation (official answer: A) PDF
- Q.91 (CDS (II) GK) · MCQ · Plant Kingdom: Plant group that is mainly aquatic (official answer: B) PDF
- Q.92 (CDS (II) GK) · MCQ · Taxonomy: Taxonomic rank for all individuals of one kind (official answer: A) PDF
- Q.93 (CDS (II) GK) · MCQ · Animal Kingdom: Source from which pearls are harvested (official answer: D) PDF
- Q.94 (CDS (II) GK) · MCQ · Evolution: Why bird and bat wings are analogous (official answer: B) PDF
- Q.95 (CDS (II) GK) · MCQ · Diseases: Bacterium linked to peptic ulcers (official answer: A) PDF
- Q.107 (CDS (II) GK) · MCQ · Plant Tissues: Correct statement on phloem (official answer: B) PDF
- Q.108 (CDS (II) GK) · MCQ · Plant Tissues: Nature of mature sclerenchyma cells (official answer: D) PDF
- Q.109 (CDS (II) GK) · MCQ · Genetics: Sex chromosomes for a female child (official answer: A) PDF
- Q.110 (CDS (II) GK) · MCQ · Microbiology: What penicillin blocks in bacteria (official answer: A) PDF
CDS2019
- Q.63 (CDS (I) GK) · MCQ · Cell Organelles: Function not carried out by smooth ER (official answer: C) PDF
- Q.64 (CDS (I) GK) · MCQ · Cell Organelles: Organelle that stores digestive enzymes (official answer: C) PDF
- Q.65 (CDS (I) GK) · MCQ · Plant Tissues: Tissue that increases stem girth (official answer: D) PDF
- Q.66 (CDS (I) GK) · MCQ · Modes of Nutrition: Organism with saprophytic nutrition (official answer: A) PDF
- Q.67 (CDS (I) GK) · MCQ · Animal Classification: Animal with bilateral symmetry (official answer: C) PDF
- Q.68 (CDS (I) GK) · MCQ · Animal Classification: Correctly grouped pair of animals (official answer: D) PDF
- Q.86 (CDS (I) GK) · MCQ · Cell Biology: Correct statement on histone proteins (official answer: B) PDF
- Q.87 (CDS (I) GK) · MCQ · Human Physiology: Correct statement on haemoglobin (official answer: B) PDF
- Q.89 (CDS (I) GK) · MCQ · Human Physiology: Correct statement on digestion and excretion (official answer: A) PDF
- Q.71 (CDS (II) GK) · MCQ · Fauna of India: Place in India with most cichlid fish (official answer: A) PDF
- Q.77 (CDS (II) GK) · MCQ · Ecology: Definition of a food chain (official answer: C) PDF
- Q.78 (CDS (II) GK) · MCQ · Cell Transport: Definition of active transport (official answer: A) PDF
- Q.79 (CDS (II) GK) · MCQ · Photosynthesis: Where chlorophyll lies in photosynthetic bacteria (official answer: B) PDF
- Q.81 (CDS (II) GK) · MCQ · Diseases: Organism that causes sleeping sickness (official answer: B) PDF
- Q.82 (CDS (II) GK) · MCQ · Human Physiology: Body part without smooth muscle (official answer: D) PDF
- Q.85 (CDS (II) GK) · MCQ · Cell Organelles: Organelle called the suicide bag of a cell (official answer: A) PDF
- Q.118 (CDS (II) GK) · MCQ · Vitamins: Acid also known as vitamin C (official answer: B) PDF
- Q.119 (CDS (II) GK) · MCQ · Cell Biology: Structure not found in animal cells (official answer: D) PDF
- Q.120 (CDS (II) GK) · MCQ · Plant Kingdom: Plant group of Marsilea, fern and horsetail (official answer: A) PDF
CDS2018
- Q.2 (CDS (I) GK) · MCQ · Human Physiology: Element involved in controlling water content of blood (official answer: A) PDF
- Q.4 (CDS (I) GK) · MCQ · Plant Nutrition: Element essential for chlorophyll formation (official answer: C) PDF
- Q.17 (CDS (I) GK) · Assertion-Reason · Human Diseases: Statement pair on spread of tuberculosis (official answer: A) PDF
- Q.18 (CDS (I) GK) · Assertion-Reason · Ecology: Statement pair on bioaccumulation of pesticides in fish (official answer: A) PDF
- Q.19 (CDS (I) GK) · MCQ · Animal Classification: Which of the named animals is a true fish (official answer: D) PDF
- Q.20 (CDS (I) GK) · MCQ · Animal Tissues: Connective tissue cell type that stores fat (official answer: A) PDF
- Q.21 (CDS (I) GK) · MCQ · Animal Classification: Mismatched pair of organism and locomotory organ (official answer: C) PDF
- Q.22 (CDS (I) GK) · MCQ · Cell Biology: Cell organelle from which lysosomes are formed (official answer: C) PDF
- Q.23 (CDS (I) GK) · MCQ · Cell Biology: Membrane layers a protein crosses to reach chloroplast thylakoid (official answer: C) PDF
- Q.48 (CDS (I) GK) · MCQ · Human Physiology: Correct statement about lymph (official answer: A) PDF
- Q.49 (CDS (I) GK) · MCQ · Animal Classification: Animal classes with a three-chambered heart (official answer: B) PDF
- Q.50 (CDS (I) GK) · MCQ · Human Physiology: Substance whose accumulation in muscles causes cramp (official answer: A) PDF
- Q.92 (CDS (I) GK) · MCQ · Wildlife: Statements on olive ridley turtles and nesting sites (official answer: B) PDF
- Q.12 (CDS (II) GK) · MCQ · Plant Physiology: Main absorbing organs of plants (official answer: C) PDF
- Q.13 (CDS (II) GK) · MCQ · Plant Physiology: Which is not a primary function of a green leaf (official answer: D) PDF
- Q.14 (CDS (II) GK) · MCQ · Plant Morphology: What defines a true fruit (official answer: D) PDF
- Q.15 (CDS (II) GK) · MCQ · Plant Physiology: Process in which plants lose water as droplets (official answer: B) PDF
- Q.16 (CDS (II) GK) · MCQ · Plant Physiology: Function affected if xylem is blocked (official answer: B) PDF
- Q.17 (CDS (II) GK) · MCQ · Plant Reproduction: Agent that does not help seed dispersal (official answer: B) PDF
- Q.33 (CDS (II) GK) · MCQ · Plant Morphology: Feature indicating a modified stem (official answer: A) PDF
- Q.34 (CDS (II) GK) · MCQ · Human Reproduction: Role of epididymis, vas deferens and accessory glands (official answer: B) PDF
- Q.35 (CDS (II) GK) · MCQ · Human Physiology: Special milk that builds a newborn's immunity (official answer: C) PDF
- Q.36 (CDS (II) GK) · MCQ · Microorganisms: Why RNA viruses mutate and evolve faster (official answer: A) PDF
CDS2017
- Q.1 (CDS (I) GK) · MCQ · Molecular Biology: Components of a DNA polynucleotide chain (official answer: A) PDF
- Q.2 (CDS (I) GK) · MCQ · Molecular Biology: Term for copying DNA information into RNA (official answer: B) PDF
- Q.3 (CDS (I) GK) · MCQ · Human Diseases: How HIV infection is transmitted (official answer: B) PDF
- Q.4 (CDS (I) GK) · MCQ · Cell Biology: What goes wrong with regulation in cancer cells (official answer: C) PDF
- Q.5 (CDS (I) GK) · MCQ · Microbiology: Genetic material of most plant viruses (official answer: B) PDF
- Q.6 (CDS (I) GK) · MCQ · Reproduction: What syngamy produces (official answer: B) PDF
- Q.7 (CDS (I) GK) · MCQ · Vitamins: Vitamin deficiency causing bleeding gums (official answer: A) PDF
- Q.24 (CDS (I) GK) · MCQ · Nutrition: Dietary cause of kwashiorkor (official answer: B) PDF
- Q.25 (CDS (I) GK) · MCQ · Human Physiology: Where the mammalian heartbeat originates (official answer: A) PDF
- Q.26 (CDS (I) GK) · MCQ · Plant Physiology: Chemical nature of plant growth regulators (official answer: B) PDF
- Q.5 (CDS (II) GK) · MCQ · Biomolecules: Protein giving silk its lustre (official answer: B) PDF
- Q.7 (CDS (II) GK) · MCQ · Cell Biology: Match cell organelles with functions (official answer: C) PDF
- Q.8 (CDS (II) GK) · MCQ · Genetics: Number of functional insulin genes in adults (official answer: B) PDF
- Q.9 (CDS (II) GK) · MCQ · Animal Products: Main constituent of pearl (official answer: A) PDF
- Q.10 (CDS (II) GK) · MCQ · Ecology: Term for a community with its environment (official answer: D) PDF
- Q.32 (CDS (II) GK) · MCQ · Human Diseases: UV radiation and skin cancer statements (official answer: C) PDF
CDS2016
- Q.1 (CDS (I) GK) · MCQ · Lipids and Health: Which lipoprotein is called good cholesterol (official answer: A) PDF
- Q.2 (CDS (I) GK) · MCQ · Vitamins: Match vitamins with deficiency diseases (official answer: B) PDF
- Q.11 (CDS (I) GK) · MCQ · Genetics: What germplasm consists of (official answer: B) PDF
- Q.12 (CDS (I) GK) · MCQ · Human Diseases: How dengue lowers platelet count (official answer: D) PDF
- Q.16 (CDS (I) GK) · MCQ · Plant Biochemistry: Name for plant sterols resembling cholesterol (official answer: A) PDF
- Q.21 (CDS (I) GK) · MCQ · Reproduction: What is introduced in artificial insemination (official answer: C) PDF
- Q.22 (CDS (I) GK) · MCQ · Biotechnology: How GM crops get modified genetic material (official answer: D) PDF
- Q.25 (CDS (I) GK) · MCQ · Vitamins: Vitamin involved in blood clotting (official answer: D) PDF
- Q.31 (CDS (I) GK) · MCQ · Biomolecules: Type of molecule glucose is (official answer: A) PDF
- Q.32 (CDS (I) GK) · MCQ · Cell Biology: Composition of protoplasm (official answer: D) PDF
- Q.33 (CDS (I) GK) · MCQ · Agriculture: Norman Borlaug's contributions (official answer: D) PDF
- Q.36 (CDS (I) GK) · MCQ · Hormones: Hormone that contains a peptide chain (official answer: D) PDF
- Q.2 (CDS (II) GK) · MCQ · Ecology: Animal group most sensitive to environmental change (official answer: A) PDF
- Q.4 (CDS (II) GK) · MCQ · Human Diseases: Cells destroyed by HIV (official answer: D) PDF
- Q.6 (CDS (II) GK) · MCQ · Reproduction: Term for embryo development without fertilisation (official answer: D) PDF
- Q.10 (CDS (II) GK) · MCQ · Human Health: Disorder caused by fluoride deficiency (official answer: A) PDF
- Q.22 (CDS (II) GK) · MCQ · Hormones: Hormone needed for glucose uptake by cells (official answer: C) PDF
- Q.23 (CDS (II) GK) · MCQ · Cell Biology: Cells that lack a nucleus (official answer: B) PDF
- Q.24 (CDS (II) GK) · MCQ · Enzymes: Properties of biological catalysts (official answer: B) PDF
- Q.25 (CDS (II) GK) · MCQ · Human Physiology: Cause of altitude sickness (official answer: B) PDF
- Q.29 (CDS (II) GK) · MCQ · Human Body: Elemental composition of the adult body by mass (official answer: B) PDF
Other General Knowledge topics
- History and Culture PYQs
- Geography PYQs
- Polity PYQs
- Economy PYQs
- Physics PYQs
- Chemistry PYQs
- Current Affairs, Defence and Sports PYQs
FAQ
How many Biology questions come in CDS?
In the official papers we tagged: 26 in 2026, 19 in 2025, 20 in 2024, 20 in 2023, 21 in 2022, 21 in 2021, 19 in 2020, 19 in 2019, 23 in 2018, 16 in 2017 and 21 in 2016 (2 papers each year). That is 225 questions in all, about 9% of General Knowledge.
Which Biology topics repeat in CDS?
Asked in the most papers: Cell Biology, Biomolecules, Human Diseases. The concept table lists every one with its count.
Are these official CDS questions?
Yes. Every question is from an official CDS paper hosted on our year pages. The one-line summaries are ours; open the PDF linked beside each question for the full text.