Quiz_Plant_Pathogen December 8, 2024 by Vijay Wardhan 1. Which of the following does not help in penetration of pathogen into the host? Piricularin Pectinase Ligninase Cutinase Explanation:Piricularin is not involved in the penetration of pathogens into the host. Enzymes like pectinase, cutinase, and ligninase help break down plant cell walls to facilitate pathogen entry. 2. Small epidermal swellings due to infection are called : Shot holes Burnts Eclema Eczema Explanation:Eclema refers to small, raised swellings on the epidermis of plants, often caused by infections or other stress factors. 3. Disease resistant plant varieties can be produced by : Hormonal treatment Heat treatment Crossing with wild varieties of plants Colchicine treatment Explanation:Crossing cultivated plants with wild varieties can introduce genes that confer resistance to diseases, thereby producing disease-resistant plant varieties. 4. Chemicals which are applied soon after the outset of infection, suppress the development of pathogen, thus curing the plant, are called : Eradicants Therapeutants Fumicides Protectants Explanation:Therapeutants are chemicals applied after the onset of infection to suppress the development of pathogens and cure the plant. They differ from protectants, which are applied preventively. 5. Late blight of potato is caused by : Fusarium moniliforme Albugo candida Alternaria solani Phytophthora infestans Explanation:Late blight of potato is caused by the oomycete Phytophthora infestans. This pathogen is notorious for causing the Irish potato famine and continues to be a significant threat to potato crops worldwide. 6. Mixed cropping helps : To increase the nitrogen content of the soil In effective control of the spread of infectious diseases To increase the yield To increase the nitrogen and phosphorus content of the soil Explanation:Mixed cropping can help control the spread of infectious diseases by reducing the density of susceptible hosts and creating a more diverse ecosystem that hinders pathogen spread. 7. The smut mycelium which initiates the infection is usually : Haploid Dikaryotic Diploid Triploid Explanation:Smut fungi typically have a dikaryotic mycelium, meaning each cell contains two genetically distinct nuclei, which is crucial for initiating infection. 8. Leaves of pea show white powdery patches due to the growth of fungal mycelium with conidia and conidiophores. These are the symptoms of : Damping off Blight Rust Mildew Explanation:Mildew refers to a fungal disease that presents as white or gray powdery patches on the surface of leaves and stems. It is caused by fungi such as Erysiphales. 9. The pathogen that causes covered smut of Sorghum is : Sphacelotheca Colletotrichum Cercospora Helminthosporium Explanation:Sphacelotheca is the pathogen responsible for covered smut in Sorghum, a disease that affects the grains and can lead to significant crop losses. 10. Which of the following is not a correct match? Cercospora-Tikka disease of groundnut Helminthosporium-Bengal famine Melampsora-Red rust of tea Aspergillus parasiticus-Aflatoxin Explanation:Melampsora is not associated with red rust of tea. Red rust of tea is caused by Cephaleuros virescens, a green alga. 11. Ergot is obtained from : Cystopus Claviceps Rhizobium Ustilago Explanation:Ergot is a fungal disease caused by Claviceps species, which infects cereal grains and produces toxic alkaloids. 12. Which of the following causes smut disease in cultivated plants? Cystopus Puccinia Phytophthora Albugo Explanation:Albugo is a genus of oomycetes that causes white rust and smut diseases in various cultivated plants. 13. Smut of maize is caused by : Ustilago maydis Ustilago avenae Ustilago nuda Ustilago hordei Explanation:Smut of maize, also known as corn smut, is caused by the fungus Ustilago maydis, which infects maize plants and forms characteristic galls. 14. Red rot of sugarcane is caused by : Helminthosporium Puccinia Colletotrichum Ustilago Explanation:Red rot of sugarcane is a fungal disease caused by Colletotrichum falcatum. It is a major disease affecting sugarcane crops, leading to significant yield losses. 15. Etiology includes the study of : Pathogen Host Disease Parasite Explanation:Etiology is the study of the causes of diseases, focusing on the pathogens responsible for causing the diseases. 16. Body disorders due to harmful physiological changes are known as : Pathology Disease Susceptibility Infection Explanation:Diseases are disorders caused by harmful physiological changes in an organism, leading to impaired function and health. 17. There is a class of phenolic compounds produced by the host plant in response to fungal infections : Gibberellins Arbutin Phytoalexins Aflatoxins Explanation:Phytoalexins are antimicrobial and often antioxidative substances synthesized by plants in response to pathogen attack. They play a crucial role in the plant’s defense mechanisms. 18. When a diseased plant is legally stopped from export, this is done under : Biological prevention Curative check Crop improvement Quarantine measure Explanation:Quarantine measures are legal actions taken to prevent the export of diseased plants, thereby controlling the spread of plant diseases. 19. Which of the following is not a fungal disease? Red rust of tea Rust disease of crucifers Rust of wheat Rust of coffee Explanation:Red rust of tea is caused by the alga Cephaleuros virescens, not by a fungus. The other diseases listed are caused by fungal pathogens. 20. A control measure prior to the appearance of a particular disease comes under : Prophylactic measure Therapentic measure Predisposition measure Curative measure Explanation:Prophylactic measures are preventive actions taken to prevent the onset of disease. These measures are implemented before any signs of the disease appear. 21. Which of the following is not a viral disease? Tobacco mosaic Red rot of sugarcane Tristeza disease of Citrus Leaf curl of papaya Explanation:Red rot of sugarcane is a fungal disease caused by Colletotrichum falcatum, not a viral disease. The other diseases listed are caused by viruses. 22. Pythium debaryanum is the causative agent of: Black wart disease of potato Powdery mildew Soft rot of sweet potato Damping off of seedling Explanation:Pythium debaryanum is a soil-borne pathogen that causes damping-off, a disease that affects seedlings, leading to their collapse and death. 23. Downy mildew disease is caused by : Puccinia Peronospora Phytophthora Albugo Explanation:Downy mildew is caused by various species of the genus Peronospora. This disease affects a wide range of plants, leading to the appearance of downy growth on the underside of leaves and significant crop damage. 24. Leaf spot of groundnut is caused by : Piricularia Sclerospora Cercospora Helminthosporium Explanation:Cercospora arachidicola is the pathogen responsible for leaf spot disease in groundnut. This disease is characterized by circular lesions on the leaves, which can lead to significant yield loss if not controlled. 25. Aflatoxin is produced as a product in : Aspergillus Penicillium Streptomyces Pathogenic bacteria Explanation:Aflatoxins are toxic metabolites produced by certain species of Aspergillus fungi, particularly Aspergillus flavus and Aspergillus parasiticus. MULTIPLE CHOICE QUESTIONS 26. When an infection is very wide in occurrence, it is called : Wide Massive Localized Systemic Explanation:A systemic infection spreads throughout the entire plant, affecting multiple tissues and organs, in contrast to localized infections that are confined to specific areas. 27. Helminthosporium oryzae was the cause of disaster : Collapse of French industry in 1870 Irish famine is 1845 Bengal famine in 1943 Displacement of planters in Ceylon in 1867 Explanation:Helminthosporium oryzae caused the Bengal famine of 1943 by devastating rice crops, leading to widespread food shortages and famine. 28. Red rot of sugarcane is caused by : Colletotrichum falcatum Alternaria solani Cercospora arachidicola Helminthosporium oryzae Explanation:Red rot of sugarcane is caused by the fungus Colletotrichum falcatum, leading to significant damage and yield loss in sugarcane crops. 29. A part of pathogen that is transmitted to the host is termed as : Infection Disease Incubation Inoculum Explanation:Inoculum refers to the part of a pathogen, such as spores or bacteria, that is transmitted to a host plant to initiate infection. 30. The causal organism of early blight of potato is : Alternaria solani Albugo candida Phytophthora infestans Cercospora personata Explanation:Early blight of potato is caused by the fungus Alternaria solani, which leads to dark, concentric spots on leaves, stems, and tubers. 31. Citrus canker is caused by : Xanthomonas oryzae Pseudomonas rubrilineans Pseudomonas solanacearum Xanthomonas citri Explanation:Citrus canker is a bacterial disease caused by Xanthomonas citri. It produces lesions on the leaves, stems, and fruits of citrus plants, leading to reduced fruit quality and yield. 32. The inability of a plant to resist the effects of a pathogen or any other damaging factors is known as : Predisposition Susceptibility Virulence Resistance Explanation:Susceptibility is the inability of a plant to resist the effects of pathogens or other damaging factors, making it more prone to disease. 33. Severe famine of West Bengal of 1942-43 was due to destruction of rice crop by a fungus called : Helminthosporium Penicillium Puccinia Rhizopus Explanation:The Bengal famine of 1942-43 was caused by the destruction of rice crops by the fungus Helminthosporium oryzae, leading to severe food shortages and starvation. 34. Propagating materials like seeds, tubers, grafts and bulbs can be kept free of pathogens by : Deep saving Giving heat, gas or chemical treatment Giving alkali treatment Giving acid treatment Explanation:Heat, gas, or chemical treatments are effective methods to sterilize propagating materials and keep them free from pathogens, ensuring healthy plant growth. 35. Which of the following is the most destructive enemies of mankind? Rust of wheat Apple scab Damping off disease Early blight of potato Explanation:Rust of wheat, caused by Puccinia species, is one of the most destructive plant diseases affecting wheat crops, leading to significant yield losses and threatening food security. 36. Chief constituents of bordeaux mixture are : Calcium oxide, copper sulphate, water Calcium sulphate, copper carbonate and water None of the above Calcium carbonate, copper carbonate and water Explanation:Bordeaux mixture is a fungicide composed of calcium oxide, copper sulphate, and water, widely used to control fungal diseases in plants. 37. A disease is abnormal state that may result due to : Mineral Environment All of these Pathogen Explanation:Diseases can be caused by various factors including environmental conditions, mineral deficiencies, or pathogens such as bacteria, viruses, and fungi. 38. If a disease appear on large scale after a long interval it is : Epiphytotic Epidemic Endemic Sporadic Explanation:An epiphytotic disease is one that appears suddenly and spreads rapidly over a large area, affecting many plants at the same time. This term is analogous to an epidemic in humans. 39. A branch of science that deals with nature, symptoms, development and control of plant diseases is called : Mycology Pathology Phytopathology Epidemiology Explanation:Phytopathology is the study of plant diseases, including their causes, symptoms, development, and control measures. 40. There are some dead and corky areas with definite margins on the stem, branches and fruits of lemon. This disease should be : Scab Canker Rust Curl Explanation:Canker is a disease characterized by sunken, dead areas on stems, branches, and fruits. It is commonly caused by bacteria or fungi and can lead to significant damage in affected plants. 41. The disease symptom necrosis refers to : Dead corky areas Rough crust-like lesions Dead tissues Burnt areas on the leaves Explanation:Necrosis is the death of plant cells or tissues, often resulting in dark, dead areas on leaves, stems, or other parts of the plant. It can be caused by various factors including pathogens and environmental stress. 42. Banana bunchy top is caused by : deuteromycetes mycoplasma virus Xanthomonas Explanation:Banana bunchy top is caused by the Banana bunchy top virus (BBTV). This virus leads to stunted growth and “bunchy” appearance of leaves, severely affecting the productivity of banana plants. 43. Quarantine regulations are concerned with: Prevention of entry of diseased plants in the country Spraying of diseased plants with insecticides Promotion of dry farming in sandy soil Growing of fruit trees in every state Explanation:Quarantine regulations aim to prevent the introduction and spread of diseased plants into a country, thereby protecting local agriculture from potential outbreaks. 44. A diseased leaf shows some areas with dead tissue. This symptom is often referred to as : Necrotic spots Chlorosis Galls Blight Explanation:Necrotic spots are areas of dead tissue on leaves or other plant parts, often caused by infections, toxins, or adverse environmental conditions. 45. In plants, the substances which accumulate around the site of infection are : Phytoalexins Pathogenesis-related proteins All of the above Saponins Explanation:Pathogenesis-related proteins, phytoalexins, and saponins are all substances that accumulate around infection sites in plants, playing a role in the plant’s defense mechanisms. 46. The disease occurring more or less regularly from year to year in a particular locality is referred to as : Epidemic disease Endemic disease Pandemic disease Sporadic disease Explanation:An endemic disease is one that is consistently present in a particular geographic area or population. It occurs regularly and at predictable rates. 47. Black rust of wheat is caused by: Puccinia Yeast Rhizopus Penicillium Explanation:Black rust of wheat, also known as stem rust, is caused by the fungus Puccinia graminis. It is a serious disease that affects wheat crops worldwide. 48. Which of the following statements is not correct? The smut spores cause enormous loss by damaging the crops The smuts commonly attack the reproductive structures of the plant The life cycle of smut is considerably less complicated than that of rusts The smuts commonly attack stem, leaves and roots Explanation:Smuts primarily attack the reproductive structures of plants, such as flowers and seeds, rather than stems, leaves, and roots. 49. The scientist who is famous for his research on rust fungi in India is : K.C. Mehta Butler Mundker Sivadasan Explanation:K.C. Mehta is renowned for his extensive research on rust fungi in India, contributing significantly to the understanding and management of rust diseases. 50. An excessive enlargement of diseased organ because of increase in the number of cells is called : Hyperplasia Hypertrophy Damping off Necrosis Explanation:Hyperplasia refers to the increase in the number of cells in an organ or tissue, causing its enlargement. This is a common response to a stimulus and can be seen in various diseases. 51. Which part of the plant is not affected by Albugo? Root Stem Flower Leaf Explanation:Albugo, the causative agent of white rust, primarily affects the aerial parts of the plant such as leaves, stems, and flowers, but not the roots. Loading …