Free NEET Biology multiple-choice questions on Ecosystems. Attempt each question and reveal the answer with a full explanation.
The term 'Ecosystem' was first proposed and coined by: A.G. Tansley E.P. Odum Karl Mobius Ernst Haeckel In a terrestrial ecosystem, what is the major conduit for energy flow? Detritus Food Chain (DFC) Grazing Food Chain (GFC) Saprophytic Chain Parasitic Chain Cocaine has a potent stimulating action on the Central Nervous System because it interferes with the transport of: Dopamine Serotonin Acetylcholine GABA Apart from lung cancer, smoking is significantly associated with an increased incidence of cancer of the: Urinary bladder Pancreas Small intestine Brain During sewage treatment, the primary effluent is passed into large aeration tanks where it is constantly agitated. This allows for the vigorous growth of: Aerobic microbes Anaerobic microbes Methanogens Parasitic fungi The principal of 'Vaccination' is based on which property of the immune system? Memory Specificity Diversity Discrimination between self and non-self Mycorrhiza, besides providing phosphorus to the plant, also helps by providing resistance to: Salinity and drought Viral infections Herbivorous insects Extreme cold Which of the following drugs acts as a depressant and slows down body functions? Heroin Cocaine Amphetamine Caffeine Which of the following are examples of secondary lymphoid organs where lymphocytes interact with antigens and proliferate? Spleen and Tonsils Bone marrow and Thymus Liver and Pancreas Kidney and Heart Single Cell Protein (SCP) can be produced using microbes that grow on waste materials. Which of the following is commonly grown on waste from potato processing plants? Spirulina Saccharomyces Lactobacillus Streptococcus A patient presents with sustained high fever ( 39 C to 40 C ), weakness, stomach pain, constipation, and loss of appetite. In severe cases, intestinal perforation occurs. Which pathogen is likely responsible? Salmonella typhi Streptococcus pneumoniae Entamoeba histolytica Plasmodium falciparum Identify the correct sequence of symptoms associated with Ascariasis, caused by the intestinal parasite Ascaris lumbricoides. Internal bleeding, muscular pain, fever, anemia and blockage of intestinal passage Sustained high fever, stomach pain, constipation and headache Nasal congestion, discharge, sore throat and cough Chronic inflammation of lymphatic vessels and swelling of lower limbs The measurement of primary productivity is more accurate when expressed in terms of: Dry weight Fresh weight Total volume Biomass per hectare Polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes represent which type of barrier in innate immunity? Cellular barriers Physical barriers Cytokine barriers Physiological barriers An 'Anamnestic response' is characterized by being: Highly intensified and based on memory Slow and of low intensity during the first encounter Non-specific and present at the time of birth Produced by the mother's milk (colostrum) Why is 'Active Immunity' generally slower than 'Passive Immunity'? It requires time for the body to recognize the antigen and produce a full immune response It involves the direct injection of pre-formed antibodies It does not involve the formation of memory cells It is only present at the time of birth Malignant tumors exhibit a property where cells slough off and reach distant sites through blood to start new tumors. This process is called: Metastasis Contact inhibition Apoptosis Differentiation Which alkaloid present in tobacco stimulates the adrenal gland to release adrenaline and nor-adrenaline? Nicotine Cocaine Morphine Codeine Which of the following drugs is chemically diacetylmorphine, a white, odorless, bitter crystalline compound? Heroin Cocaine Hashish Morphine Chronic use of anabolic steroids in females can lead to 'Masculinisation'. This includes which of the following side effects? Increased aggressiveness, mood swings, and abnormal menstrual cycles Reduction in the size of testicles and decreased sperm production Increase in height and bone density Enhanced hearing and vision What is the typical depth of the concrete tank used in a biogas plant for collecting bio-wastes and slurry of dung? 10-15 feet 2-5 feet 25-30 feet 50-60 feet The Bt toxin protein exists as inactive protoxins in Bacillus thuringiensis and is activated in the insect gut due to: The alkaline pH of the gut The acidic pH of the stomach The presence of digestive enzymes like pepsin High temperature in the insect body Integrated Pest Management (IPM) programs often utilize species-specific, narrow-spectrum insecticides such as: Baculoviruses Organophosphates Pyrethroids Carbamates In aquatic ecosystems, the major conduit for energy flow is the: Grazing Food Chain (GFC) Detritus Food Chain (DFC) Saprophytic Food Chain Parasitic Food Chain Fungi of the genus Glomus are known to form mycorrhiza, which helps the host plant primarily by: Absorbing phosphorus from the soil and passing it to the plant Providing resistance against viral infections Increasing the rate of photosynthesis Fixing atmospheric nitrogen in the root nodules Which specific region of the antibody molecule varies in its amino acid sequence to allow for the binding of diverse antigens? Variable region Constant region Fc region Hinge region After entering the human body, HIV first enters which of the following cells where it undergoes replication to act as a 'virus factory'? Macrophages Helper T-lymphocytes B-lymphocytes Cytotoxic T-cells Which of the following radiations are used as non-ionising mutagens to induce mutations in cancer research or therapy? UV rays X-rays Gamma rays Cosmic rays The misuse of anabolic steroids in females is associated with which of the following side effects? Enlargement of clitoris Increased body fat and breast development Decrease in facial and body hair Higher pitch of voice Metastasis is a characteristic feature of: Malignant tumors Benign tumors Autoimmune diseases Viral infections Fungi of the genus Glomus form mycorrhiza which, in addition to phosphorus absorption, provides the plant with: Resistance to root-borne pathogens and salinity Ability to fix atmospheric nitrogen directly Increased height and flower size Resistance to all viral infections In the treatment of allergy symptoms, doctors frequently use which of the following combinations of drugs? Anti-histamines, Adrenaline, and Steroids Antibiotics, Antivirals, and Analgesics Insulin, Glucagon, and Adrenaline Morphine, Heroin, and Codeine Cannabinoid receptors are primarily located in the brain, but they are also known for having significant effects on which body system? Cardiovascular system Digestive system Excretory system Skeletal system During secondary sewage treatment, the primary effluent is mechanically agitated in large aeration tanks primarily to: Allow vigorous growth of useful aerobic microbes Settle the heavy grit and stones Kill all the anaerobic bacteria present Maximize the production of methane gas If in a population of 40 individuals, 4 individuals die during a specified time interval (e.g., a week), the death rate of the population for that period is: 0.1 individuals per capita per week 4 individuals per week 10% per individual per week 0.4 individuals per capita per week The Bt toxin protein produced by Bacillus thuringiensis does not kill the bacterium itself because: The toxin exists as an inactive protoxin The bacterium has a thick protective cell wall The toxin is sequestered in a specialized vacuole The bacterium produces an antitoxin Baculoviruses are considered excellent biocontrol agents because they have: No negative impacts on plants, mammals, or non-target insects A very broad spectrum of activity against all invertebrates The ability to fix nitrogen in the soil while killing pests A symbiotic relationship with the host plant's roots In organic farming, the main objective is to use a system where: Pests are not eradicated but kept at manageable levels by complex systems of checks All insects are eliminated using natural botanical sprays Only one type of high-yielding crop is grown to ensure food security Chemical fertilizers are used in very low, controlled doses In the activated sludge process of sewage treatment, the 'inoculum' used for the aeration tank is: A small part of the activated sludge from the settling tank Primary sludge collected from the primary settling tank The raw sewage entering the treatment plant Pure cultures of Methanobacterium Alpha-interferon is used in the treatment of cancer because it acts as a: Biological response modifier Chemotherapeutic drug Radiotherapeutic agent Competitive inhibitor of DNA polymerase Which of the following is an autoimmune disease where the body's immune system attacks the neuromuscular junctions? Myasthenia gravis Rheumatoid arthritis Multiple sclerosis Hashimoto's thyroiditis The large vessels used for growing microbes on an industrial scale are called: Fermentors Autoclaves Incubators Digestors The secondary lymphoid organs provide the sites for interaction of lymphocytes with antigen. Which of the following is an example of such an organ? Appendix Bone marrow Thymus Pancreas Which antibody class is the most abundant in the serum and is the only one capable of crossing the human placenta? IgG IgA IgM IgE During the life cycle of Plasmodium , where exactly do the gametocytes develop within the human host? In the red blood cells In the liver cells In the salivary glands In the stomach wall In a logistic growth curve, the asymptote is reached when: N = K The value of 'r' approaches zero K is much greater than N The population enters the log phase In the context of the immune system, what does the acronym 'PMNL' stand for? Polymorpho-nuclear Leukocytes Primary Mono-nuclear Lymphocytes Pathogen-Mediated Neutrophil Lysis Peripheral Memory Neutralizing Lymphocytes The 'Thymus' gland is a primary lymphoid organ located in which of the following positions? Near the heart, beneath the sternum In the abdominal cavity, near the spleen In the neck, near the thyroid gland Attached to the dorsal side of the liver If a person is bitten by a snake and is given 'Antivenom', what type of immunity is being provided? Artificial passive immunity Natural active immunity Artificial active immunity Natural passive immunity In cancer diagnosis, 'Biopsy' involves the examination of which of the following? A thin section of suspected tissue stained and examined under a microscope The entire organ removed via surgery Blood samples for white blood cell count only Urine samples for metabolic by-products of tumors The side effect of 'Gynecomastia' (enlargement of breasts) is seen in males due to the misuse of which substance? Anabolic steroids Morphine Cannabinoids Nicotine Which of the following describes the relationship between Biochemical Oxygen Demand (BOD) and water pollution? BOD is directly proportional to the amount of organic matter BOD is inversely proportional to the amount of organic matter BOD is unrelated to the degree of pollution BOD decreases as the organic waste increases What is the primary role of 'Pectinases' and 'Proteases' in the food industry? Clarification of bottled fruit juices Improving the texture of bread Enhancing the flavor of cheese Preserving canned vegetables The Ladybird and Dragonflies are useful to get rid of and respectively. Aphids; Mosquitoes Mosquitoes; Aphids Caterpillars; Beetles Beetles; Caterpillars Which specific genus of fungi is utilized as a biocontrol agent for its ability to live freely in root ecosystems and protect plants from pathogens? Trichoderma Glomus Aspergillus Rhizopus The species-specific, narrow-spectrum insecticidal activity of Baculoviruses makes them ideal for which of the following? Integrated Pest Management (IPM) Broad-scale agricultural spraying Eradication of all insects in a region Fertilizer production The integral form of the exponential growth equation is represented as: N t = N 0 e rt N t = N 0 + rt dN/dt = rN r = (N t - N 0) / t During the conversion of milk into curd, the Lactic Acid Bacteria (LAB) also perform which helpful function in the human stomach? Checking the growth of disease-causing microbes Increasing the secretion of digestive enzymes Synthesizing Vitamin C Reducing the acidity of the stomach In the context of the malarial parasite, 'Haemozoin' is a toxic substance released when which of the following occurs? Rupture of Red Blood Cells Lysis of liver cells Bite by the mosquito Fertilization in the mosquito gut Which of the following drugs is known to interfere with the transport of the neurotransmitter dopamine? Cocaine Morphine Marijuana LSD Smoking tobacco leads to an increase in the blood levels of which molecule that reduces the concentration of haembound oxygen? Carbon monoxide ( CO ) Carbon dioxide ( CO 2 ) Nicotine Tar The side effects of anabolic steroids in females include which of the following 'masculinising' features? Deepening of voice Decrease in aggressiveness Increased body fat Excessive sleepiness Which of the following is a cannabinoid receptor primarily located in the brain? CB1 CB2 Opioid receptor Nicotinic receptor Which of the following is used in the treatment of cancer? α -interferon γ -globulin H 1 blockers Penicillin In the structure of an HIV virus, the genetic material is composed of: Two identical molecules of single-stranded RNA Two identical molecules of double-stranded DNA A single molecule of double-stranded RNA A single molecule of single-stranded DNA Many members of the genus form mycorrhiza. Glomus Nostoc Oscillatoria Azolla Statins, used for lowering blood cholesterol, inhibit the enzyme responsible for the synthesis of cholesterol through: Competitive inhibition Non-competitive inhibition Allosteric modulation Feedback inhibition Organisms that can tolerate and thrive in only a narrow range of temperatures are called: Stenothermal Eurythermal Poikilothermal Homeothermal Which of the following microorganisms is used for the production of nitrogen-fixing nodules on the roots of non-leguminous plants like Alnus? Frankia Rhizobium Azotobacter Beijerinckia After entering the human body, HIV replicates within which cells to act as an 'HIV factory'? Macrophages B-lymphocytes Erythrocytes Basophils Integrated Pest Management (IPM) programs often utilize Baculoviruses because they are: Species-specific and narrow spectrum Broad-spectrum and effective against all insects Pathogenic to birds and mammals Effective only against large mammals At which stage of HIV infection does one usually show symptoms of AIDS? When HIV replicates rapidly in helper T-lymphocytes and damages large number of these Within 15 days of sexual contact with an infected person When the infecting retrovirus enters host cells When viral DNA is produced by reverse transcriptase Which of the following effects is NOT typically associated with the misuse of anabolic steroids in male adolescents? Increased height Acne Reduction in size of testicles Premature closure of the growth centers of long bones The drug 'LSD' (Lysergic acid diethylamide) is obtained from which of the following sources? Claviceps purpurea Cannabis sativa Papaver somniferum Atropa belladonna Which of the following can be used as a biofertilizer for a non-leguminous plant like Alnus? Frankia Rhizobium Azotobacter Anabaena The use of anabolic steroids in male adolescents can lead to which of the following permanent side effects? Premature closure of growth centers of long bones Increased height Enhanced liver function Increased sperm production Which microorganism can produce 25 tonnes of protein per day due to its high rate of biomass production and growth? Methylophilus methylotrophus Saccharomyces cerevisiae Bacillus thuringiensis Trichoderma polysporum The use of anti-histamines, adrenaline, and steroids quickly reduces the symptoms of: Allergy Typhoid Cancer Malaria In a population, if the rate of addition of new members is more than the rate of individuals lost, the growth curve will be: J-shaped S-shaped Linear Declining The variable region of an antibody molecule, where the antigen-binding site is located, is found at the: N-terminal of both heavy and light chains C-terminal of both heavy and light chains C-terminal of heavy chains only N-terminal of light chains only In the structure of an antibody molecule, the 'antigen-binding site' is formed by the interaction of: Variable regions of both light and heavy chains Constant regions of heavy chains only Variable regions of light chains only Disulfide bonds between the two heavy chains Statins, the blood-cholesterol lowering agents, act by which mechanism? Competitive inhibition of the enzyme responsible for cholesterol synthesis Digestion of cholesterol in the small intestine Binding to cholesterol and excreting it via bile Increasing the breakdown of LDL in the liver In a typical antibody molecule, how many disulfide bonds are specifically involved in holding the two heavy chains together? Two One Four Six The genetic material of HIV consists of how many molecules of single-stranded RNA? Two identical molecules One molecule Four identical molecules Two different molecules Which of the following microorganisms is capable of producing 25 tonnes of protein per day due to its high rate of biomass production? Methylophilus methylotrophus Spirulina Saccharomyces cerevisiae Bacillus subtilis The lag phase in the immune response is significantly reduced during which of the following? Secondary immune response Primary immune response Innate immune response Initial vaccination phase During HIV replication, which enzyme is responsible for incorporating the viral DNA into the host cell's genome? Integrase Reverse Transcriptase RNA Polymerase DNA Ligase Which benefit is NOT provided to a plant by its association with Glomus in mycorrhiza? Production of atmospheric nitrogen Resistance to root-borne pathogens Tolerance to salinity and drought Enhanced absorption of phosphorus Which of the following is the 'HIV factory' where the virus replicates continuously to increase its count in the body? Macrophages T-helper cells B-lymphocytes Red Blood Cells In most terrestrial ecosystems, what percentage of the energy is lost as heat at each trophic level? 90% 10% 50% 1% In which disease does a mosquito transmitted pathogen cause chronic inflammation of lymphatic vessels? Elephantiasis Amoebiasis Ringworm disease Ascariasis Primary treatment of sewage is basically a process of: Physical removal of particles Biological degradation of organic matter Chemical neutralization of toxins Removal of nitrates and phosphates In a sewage treatment plant, the 'activated sludge' is primarily composed of: Bacterial flocs with trapped fungal filaments Sedimented grit and pebbles Anaerobic methanogenic bacteria only Dissolved organic salts Which of the following symptoms are associated with Ascariasis? Internal bleeding, muscular pain, fever, anemia and blockage of intestinal passage Chronic inflammation of lymphatic vessels of lower limbs Sore throat, nasal congestion, and headache High fever, weakness, stomach pain, and constipation The primary and secondary immune responses are carried out with the help of two special types of lymphocytes present in our blood, which are: B-lymphocytes and T-lymphocytes Monocytes and Macrophages Neutrophils and Eosinophils Mast cells and Basophils Which type of immunity is provided when ready-made antibodies are directly given to protect the body against foreign agents? Passive immunity Active immunity Innate immunity Cell-mediated immunity The yellowish fluid 'Colostrum' contains which class of antibodies? IgA IgG IgE IgM Malignant malaria is caused by which species of Plasmodium ? P. falciparum P. vivax P. malariae P. ovale Cancer-causing genes are called: Oncogenes Structural genes Regulatory genes Jump genes Morphine is extracted from the latex of which plant? Papaver somniferum Atropa belladonna Cannabis sativa Erythroxylum coca Organisms that can tolerate and thrive in a wide range of temperatures are called: Eurythermal Stenothermal Euryhaline Stenohaline Which of the following drugs is a very effective sedative and painkiller, often used for patients who have undergone surgery? Morphine Heroin Cocaine Hashish Coca alkaloid or cocaine is obtained from the plant Erythroxylum coca , which is native to: South America South Africa North America East India Colostrum, the yellowish fluid, secreted by mother during the initial days of lactation is very essential to impart immunity to the newborn infants because it contains: Immunoglobulin A Natural killer cells Monocytes Macrophages Which microorganism is used to produce 'Swiss cheese' characterized by large holes? Propionibacterium sharmanii Saccharomyces cerevisiae Lactobacillus Penicillium roqueforti The 'Clot buster' enzyme Streptokinase is produced by which bacterium? Streptococcus Staphylococcus Bacillus Clostridium Cyclosporin A is produced by the fungus: Trichoderma polysporum Monascus purpureus Aspergillus niger Penicillium notatum The blood-cholesterol lowering agent 'Statin' is obtained from the yeast: Monascus purpureus Saccharomyces cerevisiae Candida albicans Propionibacterium Which gas is predominantly found in 'Biogas' produced during anaerobic digestion of sludge? Methane ( CH 4 ) Hydrogen sulfide ( H 2S ) Carbon dioxide ( CO 2 ) Nitrogen ( N 2 ) The technology of biogas production was developed in India mainly due to the efforts of: IARI and KVIC ICAR and CSIR NEERI and FRI WHO and UNICEF Which free-living fungus is used as a common biocontrol agent for the treatment of plant diseases? Trichoderma Glomus Rhizobium Nostoc When resources in the habitat are unlimited, the population growth follows which type of curve? Exponential Logistic Sigmoid Declining Which type of ecological pyramid is NEVER inverted? Pyramid of Energy Pyramid of Biomass in terrestrial ecosystem Pyramid of Numbers in a grassland Pyramid of Biomass in a pond Baculoviruses belong to the genus: Nucleopolyhedrovirus Retrovirus Rhinovirus Bacteriophage In paddy fields, which of the following serve as an important biofertilizer? Cyanobacteria (Blue-green algae) Mycorrhiza Rhizobium Azo-spirillum The genus Glomus is known for forming: Mycorrhiza Nitrogen-fixing nodules Lichens Antibiotics MALT constitutes about percent of the lymphoid tissue in human body. 50% 20% 70% 10% During the conversion of milk into curd, LAB (Lactic Acid Bacteria) improve its nutritional quality by increasing the content of: Vitamin B 12 Vitamin C Vitamin D Vitamin A The classic case in medicine, 'Typhoid Mary', was a carrier of typhoid by profession as a: Cook Nurse Teacher Doctor A traditional drink of some parts of Southern India is made by fermenting sap from palms. What is it called? Toddy Fenny Bhang Tequila Which lymphoid organ is quite large at the time of birth but keeps reducing in size with age and becomes very small by the time puberty is attained? Thymus Spleen Tonsils Bone marrow Chronic use of drugs and alcohol can lead to severe damage to the nervous system and liver, a condition known as: Cirrhosis Metastasis Leukaemia Gastritis The property of 'Metastasis' is most commonly associated with: Malignant tumors Benign tumors Autoimmune diseases Secondary immune response During ecological succession, the entire sequence of communities that successively change in a given area are called: Sere Pioneer Climax Niche Heroin, commonly called 'smack', chemically is diacetylmorphine. It acts as a: Depressant Stimulant Hallucinogen Painkiller used only in mild cases In the life cycle of the Malarial parasite (Plasmodium), the infectious stage (sporozoites) are stored in the of the female Anopheles mosquito. Salivary glands Stomach Intestine Hemolymph Wuchereria bancrofti and Wuchereria malayai are the filarial worms that cause a slowly developing chronic inflammation of the: Lymphatic vessels of lower limbs Blood vessels of upper limbs Alveoli of lungs Mucosa of the large intestine The common cold is characterized by nasal congestion and discharge, sore throat, and hoarseness, usually lasting for 3-7 days. It is caused by: Rhinoviruses Streptococcus pneumoniae Haemophilus influenzae Plasmodium vivax The substance produced by a cell in viral infection that can protect other cells from further infection is: Interferon Serotonin Colostrum Histamine An antibody molecule is represented as H 2L 2 because it consists of: Two heavy chains and two light chains Two heavy chains and one light chain One heavy chain and two light chains Four identical chains Cocaine is known to interfere with the transport of which neurotransmitter? Dopamine Serotonin Acetylcholine GABA The use of which of the following microorganisms is helpful in the production of Statins used for lowering blood cholesterol? Monascus purpureus Saccharomyces cerevisiae Trichoderma polysporum Aspergillus niger Which of the following is an example of a cytokine barrier of innate immunity? Interferons Polymorpho-nuclear leukocytes (PMNL) Mucus coating of the epithelium Saliva in the mouth Which of the following is the largest reservoir of erythrocytes in the human body? Spleen Thymus Lymph nodes Bone marrow In a grazing food chain, the energy flow is primarily from: Living producers to herbivores Dead organic matter to detritivores Carnivores to decomposers Inorganic nutrients to producers The clinical test ELISA (Enzyme-Linked Immuno-Sorbent Assay) is based on the principle of: Antigen-antibody interaction DNA replication Radioactive decay Protein synthesis Which of the following chemicals is released by mast cells during an allergic reaction? Histamine and Serotonin Adrenaline and Nor-adrenaline Thyroxine and Insulin Dopamine and Melatonin Which plant is known for its hallucinogenic properties and belongs to the same category as Atropa belladonna? Datura Papaver somniferum Erythroxylum coca Cannabis sativa Which of the following is a physical process used in the primary treatment of sewage to remove floating debris? Sequential filtration Sedimentation Aeration Anaerobic digestion Alexander Fleming discovered Penicillin while working on which of the following bacterial genera? Staphylococci Streptococci Bacillus Pneumococci Short-lived immunity acquired from mother to foetus across placenta or through mother's milk to the infant is categorized as: Passive immunity Active immunity Innate immunity Cellular immunity Which fungus is commonly used as a biocontrol agent against several plant pathogens and is free-living in the root ecosystems? Trichoderma Glomus Rhizopus Aspergillus Which of the following is a symptom of 'Withdrawal Syndrome' due to abrupt discontinuation of drug or alcohol use? Anxiety and shakiness Euphoria and high energy Increased concentration Deep sleep Lipases are added in detergent formulations primarily to help in: Removing oily stains from the laundry Providing a pleasant fragrance Bleaching the clothes Increasing the shelf life of the detergent Which of the following is a nitrogen-fixing cyanobacterium that can also serve as a biofertilizer in paddy fields? Anabaena Azotobacter Rhizobium Clostridium Which of the following population interactions is represented by the relationship between an orchid growing on a mango branch? Commensalism Mutualism Parasitism Amensalism Which of the following acts as the 'filter of the blood' by trapping blood-borne microorganisms? Spleen Thymus Tonsils Peyer's patches Rheumatoid arthritis is categorized as which type of disease? Autoimmune disease Infectious disease Deficiency disease Allergic disease In the large-scale production of microbes, the vessels used are called 'fermentors'. The process of growing microbes in them under controlled conditions is: Fermentation Distillation Sedimentation Filtration In the structure of an antibody molecule, the four polypeptide chains are held together primarily by which type of chemical bonds? Disulfide bonds Hydrogen bonds Glycosidic bonds Phosphodiester bonds Which of the following organisms is used for the commercial production of 'Statins', which are blood-cholesterol lowering agents? Monascus purpureus Saccharomyces cerevisiae Trichoderma polypsorum Aspergillus niger Which of the following is a non-pathogenic, free-living fungus that is very common in the root ecosystem and used as a biocontrol agent for several plant pathogens? Trichoderma Glomus Baculovirus Rhizobium In higher vertebrates, the immune system can distinguish self-cells and non-self cells. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to: Auto-immune disease Active immunity Allergic response Graft rejection Which of the following enzymes is used to remove 'bottled juice' turbidity by breaking down fruit pectin? Pectinases Lipases Amylases Cellulases The symbiotic association between fungi and the roots of higher plants (Mycorrhiza) helps the plant primarily in the absorption of which element? Phosphorus Nitrogen Potassium Calcium The genus of viruses used as species-specific, narrow spectrum insecticidal applications is: Nucleopolyhedrovirus Adenovirus Retrovirus Bacteriophage The interaction between 'Amensalism' is represented by which of the following symbols (Species A, Species B)? (-, 0) (-, -) (+, -) (+, 0) The 'T-cells' of the immune system mature in which of the following lymphoid organs? Thymus Bone marrow Spleen Peyer's patches Which of the following is an example of 'Cytokine barriers' of innate immunity? Interferons Monocytes Saliva in mouth Mucus coating of epithelium The property of 'Metastasis' refers to: Spread of cancerous cells to distant sites via blood Uncontrolled division of normal cells Loss of the property of contact inhibition Formation of benign tumors in one location What is the biochemical nature of the 'Bt toxin' produced by Bacillus thuringiensis? Protein Lipid Polysaccharide Nucleic acid During an allergic reaction, the binding of allergens to which of the following antibodies triggers the release of histamine from mast cells? IgE IgA IgG IgM The 'Ladybird' beetle is a very useful biocontrol agent used to control the population of which pest? Aphids Mosquitoes Caterpillars Bollworms The enzyme 'Streptokinase', used as a clot buster, is obtained from which microorganism? Streptococcus Staphylococcus Lactobacillus Saccharomyces Which part of the poppy plant is used to obtain the drug "Smack"? Latex Leaves Flowers Roots Which species of Plasmodium causes the most serious and even fatal 'Malignant malaria'? Plasmodium falciparum Plasmodium vivax Plasmodium malariae Plasmodium ovale Which of the following is a symptom of 'Withdrawal Syndrome' when a drug addict suddenly stops consuming the drug? Anxiety and shakiness Euphoria and high energy Loss of appetite and weight gain Improved focus and sleep A majority (99 percent) of animals and nearly all plants cannot maintain a constant internal environment. Their body temperature changes with the ambient temperature. These organisms are called: Conformers Regulators Partial Regulators Endotherms Roquefort cheese is ripened by growing a specific fungus on it, which gives it a particular flavor. This fungus is: Penicillium roqueforti Propionibacterium sharmanii Saccharomyces cerevisiae Aspergillus niger If a person is potentially infected with Clostridium tetani during an accident, they are often given an injection of antitoxin. This provides: Passive immunization Active immunization Autoimmunity Innate immunity The Ganga Action Plan and Yamuna Action Plan to save these major rivers from pollution were initiated by the: Ministry of Environment and Forests Ministry of Health and Family Welfare Ministry of Agriculture Ministry of Water Resources Which fish is specifically introduced into ponds to control the spread of mosquito-borne diseases like malaria and dengue? Gambusia Labeo Catla Exocoetus Mucus coating of the epithelium lining the respiratory, gastrointestinal, and urogenital tracts is part of which innate immunity barrier? Physical barrier Physiological barrier Cellular barrier Cytokine barrier Marijuana, hashish, charas, and ganja are produced from different parts of the plant: Cannabis sativa Papaver somniferum Atropa belladonna Erythroxylum coca Bottled fruit juices are clearer than homemade ones because they are treated with which enzymes? Pectinases and Proteases Lipases and Amylases Cellulases and Hemicellulases Ligases and Polymerases The puffed-up appearance of dough used for making 'Idli' and 'Dosa' is due to the production of CO 2 gas by: Bacteria Fungi Viruses Protozoa Secondary succession takes place on/in: Degraded forests Newly cooled lava Bare rock Newly created pond The interaction between a clownfish that lives among the stinging tentacles of sea anemones and the anemone itself is an example of: Commensalism Mutualism Parasitism Amensalism In a population, if the age pyramid shows a broad base of younger individuals, it indicates that the population is: Expanding Stable Declining At equilibrium Succession that occurs in areas where natural biotic communities have been destroyed, such as abandoned farm lands or burned forests, is called: Secondary succession Primary succession Autogenic succession Xerarch succession The amount of nutrients, such as carbon, nitrogen, phosphorus, and calcium, present in the soil at any given time is referred to as the: Standing state Standing crop Climax state Trophic state Which ecological concept describes the vertical distribution of different species occupying different levels in a tropical rainforest, such as trees in the top layer and herbs in the bottom layer? Stratification Zonation Succession Fragmentation The community that is in near equilibrium with the environment and represents the final stage of ecological succession is called the: Climax community Pioneer community Seral community Transient community The process where a nutrient-enriched water body supports a dense plant population, leading to oxygen depletion is: Eutrophication Biomagnification Stratification Humification In the equation S = C + Z A , what does ' Z ' represent? Slope of the line (regression coefficient) Species richness Area of the region Y-intercept The relation between species richness and area for a wide variety of taxa turns out to be a: Rectangular hyperbola Linear graph Sigmoid curve J-shaped curve In the following biome graph, which region represents the 'Tropical Forest'? Region with highest mean annual temperature and high precipitation Region with lowest mean annual temperature and low precipitation Region with moderate temperature and low precipitation Region with high temperature and lowest precipitation Gause's Principle of Competitive Exclusion states that: Two closely related species competing for the same resources cannot co-exist indefinitely Larger organisms always exclude smaller ones Competition leads to mutualism over time Interspecific competition always leads to extinction of both species What is the 'Standing Crop' in an ecosystem? The mass of living material at a particular time in a trophic level The amount of inorganic nutrients present in the soil at a given time The total amount of solar energy trapped by producers The rate of biomass production by consumers In the context of ecological succession, which of the following is characteristic of a 'Climax Community'? It is in near equilibrium with the environment It has low species diversity It is the first community to colonize a bare area It is highly unstable and changes rapidly Robert MacArthur showed that five closely related species of warblers living on the same tree were able to avoid competition and co-exist due to: Resource partitioning Competitive exclusion Predation Parasitism The relationship between the fig tree and the pollinating wasp species is an example of: Mutualism Commensalism Parasitism Amensalism Alexander von Humboldt observed that within a region, species richness increased with increasing explored area, but only up to a limit. This relationship for many taxa is a: Rectangular hyperbola Linear function Sigmoid curve Parabola Antibiotics produced by some bacteria that inhibit the growth of other bacteria is an example of: Amensalism Commensalism Competition Mutualism Which of the following is a site where primary succession would occur? Newly cooled lava Abandoned farm lands Burned forests Flooded lands The functional role played by an organism in its ecosystem, including the physical space it occupies and its interactions, is its: Ecological niche Habitat Biome Trophic level Barnacles growing on the back of a whale is an example of: Commensalism Parasitism Amensalism Mutualism Based on David Tilman's long-term ecosystem experiments on outdoor plots, which of the following is true regarding plots with more species? They showed less year-to-year variation in total biomass. They showed more year-to-year variation in total biomass. They showed significantly less total biomass than plots with fewer species. Increased diversity contributed to lower productivity. In the species-area relationship, what is the observed range of the slope of the regression line ( Z ) regardless of the taxonomic group or region (e.g., plants in Britain, birds in California)? 0.1 to 0.2 0.6 to 1.2 1.0 to 2.0 0.01 to 0.1 Which ecosystem has the maximum Net Primary Productivity per unit area? Tropical Rain Forest Coral Reefs Temperate Forests Estuaries The interaction where one species is harmed and the other is unaffected is called: Amensalism Commensalism Competition Mutualism Species that have a large effect on the structure and function of an ecosystem, far out of proportion to their abundance, are called: Keystone species Endemic species Pioneer species Invasive species Which of the following statements about competition is CORRECT according to modern ecological findings? Species facing competition might evolve mechanisms like 'resource partitioning' to co-exist. Two closely related species competing for the same resources can coexist indefinitely. Competition only occurs between closely related species. Competition only occurs when resources are limited. The slope of the species-area relationship ( Z ) for very large areas like entire continents is found to be in the range of: 0.6 to 1.2 0.1 to 0.2 1.5 to 2.5 0.01 to 0.05 Which of the following characteristics is typical of an r -selected species? Large number of small-sized offspring Small number of large-sized offspring Extensive parental care Long life span Out of the total cost of various ecosystem services estimated by Robert Costanza and his colleagues, the cost of 'soil formation' accounts for approximately: 50 percent 10 percent 6 percent Less than 5 percent What is the annual net primary productivity of the whole biosphere, and how much of it is contributed by the oceans? 170 billion tons and 55 billion tons 170 billion tons and 115 billion tons 55 billion tons and 170 billion tons 115 billion tons and 55 billion tons The Mediterranean orchid Ophrys employs 'sexual deceit' to get pollination done by a species of bee. This interaction is a specific example of: Co-evolution Amensalism Commensalism Competition Which of the following ecological pyramids can be spindle-shaped (broader in the middle and narrower at both top and bottom)? Pyramid of numbers in a tree ecosystem Pyramid of energy in a grassland Pyramid of biomass in a forest Pyramid of numbers in a pond Approximately what percentage of the total carbon is found dissolved in the oceans? 71 percent 1 percent 49 percent 10 percent According to the Species-Area relationship, for very large areas like entire continents, the slope of the line ( Z ) is much steeper and lies in the range of: 0.6 to 1.2 0.1 to 0.2 1.5 to 2.0 0.01 to 0.05 The vertical distribution of different species occupying different levels in a biotic community is known as: Stratification Zonation Pyramid Succession In the hydrarch succession, which stage foll