Untitled Quiz

Plants defend themselves against pathogens by structural characteristics and biochemical reactions.

Examples include the amount and quality of wax and cuticle, the thickness of cuticle, the structure of epidermal cells, the size, location, and shape of natural openings, and the presence of thick-walled cells in the tissues of the plant that hinder the advance of a pathogen.

<p>The citrus variety, szinkum, is resistant to citrus canker because it has a broad cuticular ridge projecting over its stomata and a narrow slit that leads to the stomatal cavity, preventing bacterial cells from entering the leaf.</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>The two types of cellular defense structures are histological defense barriers and cellular defense structures.</p> Signup and view all the answers

<p>The cork layer acts as a barrier to infection, preventing the pathogen from invading deeper into the plant and also blocks the spread of toxic substances secreted by the pathogen.</p> Signup and view all the answers

<p>Abscission layers are formed to isolate the infected area from the healthy part of the plant, preventing the spread of pathogens.</p> Signup and view all the answers

<p>Tyloses are outgrowths of living parenchyma cells that protrude into xylem vessels, blocking the passage of pathogens and essentially clogging the xylem to stop the spread of the pathogen.</p> Signup and view all the answers

<p>Gum deposition occurs when the gums and vascular gels quickly fill the intercellular spaces or within the cell surroundings the infection thread and haustoria, starving the pathogen or causing it to die.</p> Signup and view all the answers

<p>The process by which a plant produces a physical barrier that surrounds the hyphae of a fungus. (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>The two types of inhibitors are inhibitors released by the plant in its environment and inhibitors present in plant cells before infection.</p> Signup and view all the answers

<p>Phytoalexins</p> Signup and view all the answers

<p>The hypersensitive response is a localized induced cell death in the host plant at the site of infection by a pathogen, restricting the growth of the pathogen.</p> Signup and view all the answers

<p>Pathogenesis-related proteins are a structurally diverse group of plant proteins that are toxic to invading fungal pathogens.</p> Signup and view all the answers

<p>Systemic acquired resistance (SAR) is a form of induced resistance in plants that is triggered by exposing the plant to virulent, avirulent, or non-pathogenic organisms or chemicals. It is dependent on the accumulation of PR-proteins and salicylic acid (SA) throughout the plant.</p> Signup and view all the answers

<p>Induced systemic resistance (ISR) is a form of induced resistance that is potentiated by plant growth promoting rhizobacteria (PGPR). It is dependent on the ethylene and jasmonate signaling pathways, but independent of salicylic acid (SA) and is not associated with the accumulation of PR proteins.</p> Signup and view all the answers

<p>A plantibody is an antibody produced by genetically modified plants, which are often able to provide resistance to specific plant pathogens.</p> Signup and view all the answers

<p>The five principles of plant disease management are avoidance, exclusion, eradication, protection, and disease resistance.</p> Signup and view all the answers

<p>Integrated plant disease management (IPDM) is a comprehensive approach to plant disease management that utilizes a combination of all available techniques, including cultural, biological, chemical, and physical methods, to keep the pathogen population below the economic threshold level.</p> Signup and view all the answers

<p>Seed pathology is the study of seed diseases, seedborne plant diseases, their detection, and management.</p> Signup and view all the answers

<p>Pathogens can be transmitted through seeds internally, externally, or by being attached to the seed at various stages.</p> Signup and view all the answers

<p>Mycotoxins are toxic metabolites produced by certain fungi, which can contaminate food and feed and have detrimental effects on human and animal health.</p> Signup and view all the answers

<p>Humans can be exposed to aflatoxins through the ingestion of contaminated food of vegetable origin, contaminated milk and dairy products, and meat and meat products.</p> Signup and view all the answers

<p>Nematicides can be classified as fumigants (halogenated hydrocarbons) or non-fumigants (organo phosphates).</p> Signup and view all the answers

<p>The four main types of fungicide formulations are powder, liquid, granular, and other.</p> Signup and view all the answers

<p>Protection involves preventing the pathogen from entering or establishing itself in the host, while therapy is the treatment of an already infected plant to cure the disease.</p> Signup and view all the answers

<p>Fungicides are classified into three categories: Protectants, eradicants, and therapeutants.</p> Signup and view all the answers

<p>Antibiotics are chemical substances produced by microorganisms that, at low concentrations, can inhibit or even kill other microorganisms.</p> Signup and view all the answers

<p>The three main categories of disease management strategies are cultural, biological, and chemical methods.</p> Signup and view all the answers

<p>The three main methods of seed treatment are mechanical, chemical, and physical.</p> Signup and view all the answers

<p>Transplantation (C)</p> Signup and view all the answers

<p>The five main methods of soil application are soildrenching, broadcasting, furrow application, fumigation, and chemigation.</p> Signup and view all the answers

<p>The primary goal of plant disease management is to minimize the damage or loss caused by plant diseases while keeping the pathogen population below the economic threshold level.</p> Signup and view all the answers

<p>The main objective of the disease forecasting system is to predict the occurrence of plant disease in a specified area ahead of time, so appropriate control measures can be implemented before significant losses occur.</p> Signup and view all the answers

<p>Koch's postulates are a set of criteria that must be met to establish that a specific organism is the cause of a particular disease. Pathogen identification often involves using Koch's postulates to verify that a particular organism is the cause of the observed disease symptoms.</p> Signup and view all the answers

<p>The main categories of techniques used to detect and diagnose plant diseases are conventional methods and advanced techniques.</p> Signup and view all the answers

<p>The four main steps involved in plant disease diagnosis are obtaining background information on the host and disease, identifying characteristic symptoms, conducting visual observations, and conducting lab tests.</p> Signup and view all the answers

<p>A sign of a plant disease is a direct indication of the presence of the pathogen, such as fungal spores, bacterial ooze, or viral particles. A symptom of a plant disease is a change in the plant's appearance or function as a result of infection, such as leaf spots, wilting, or gall formation.</p> Signup and view all the answers

<p>The two main types of plant disease resistance are vertical resistance and horizontal resistance.</p> Signup and view all the answers

<p>The gene-for-gene hypothesis states that for each gene conditioning rust reaction in the host plant, there is a corresponding gene for avirulence in the pathogen.</p> Signup and view all the answers

<p>Disease resistance refers to the ability of a plant to prevent or limit infection by a pathogen, while disease tolerance refers to the ability of a plant to withstand infection and continue to produce a good yield even when infected.</p> Signup and view all the answers

<p>The three main methods for breeding disease-resistant varieties are introduction, selection, and hybridization.</p> Signup and view all the answers

<p>Tissue culture offers several advantages for plant disease management, including the production of virus-free plants, the development of new varieties with disease resistance, and the creation of somaclonal variations for disease resistance.</p> Signup and view all the answers

<p>Molecular markers are used to identify and tag desirable genes, to mark traits in living organisms, and to identify resistance genes in plants and pathogenicity genes in pathogens.</p> Signup and view all the answers

<p>The three main types of tissue culture techniques are somaclonal variations, somatic hybridization, and meristem tip culture.</p> Signup and view all the answers

<p>The main goal of gene cloning is to isolate and copy a specific gene from one organism and insert it into another organism where it can be expressed.</p> Signup and view all the answers

<p>The key steps involved in gene cloning are isolating the desired gene, inserting the gene into a suitable vector, introducing the vector into a host cell, selecting transformed host cells, and multiplying and integrating the introduced gene into the host genome.</p> Signup and view all the answers

<p>Nematodes are unsegmented, cylindrical or worm-like organisms that are ubiquitous in soil and water and can be parasitic or free-living.</p> Signup and view all the answers

<p>Nematodes can be classified based on their feeding habits as ectoparasites, semi-endoparasites, and endoparasites.</p> Signup and view all the answers

<p>Nematode-induced damage can be categorized as gall-forming or non-gall forming. Gall-forming nematodes cause the formation of galls or swellings on plant tissues, while non-gall forming nematodes cause other types of damage, such as lesions or root rot.</p> Signup and view all the answers

<p>Above-ground symptoms caused by nematode infections include leaf discoloration, yellowing, stunting, day wilting, malformation, and patchiness.</p> Signup and view all the answers

<p>Root galls caused by root-knot nematodes can be classified as compound, simple, bead like, elongated root tip, and pit.</p> Signup and view all the answers

<p>IPDM is considered more sustainable than conventional methods because it avoids chemical pollution of soil, water, and food products, minimizes the development of resistance in pathogens to fungicides, and is economically feasible.</p> Signup and view all the answers

<p>The key principles of IPDM in rice cultivation include the selection of healthy seed, the selection of resistant cultivars, the removal and destruction of collateral hosts, balanced fertilization, rouging of diseased plants, and need-based applications of fungicides and biocontrol agents.</p> Signup and view all the answers

<p>The key principles of IPDM in sugarcane cultivation include collecting and destroying infected crop debris, treating setts with hot water or hot air, using a balanced irrigation and fertilization program, avoiding the selection of seed material from ratoon crops, using need-based sprays of systemic insecticides to minimize the spread of viral and phytoplasmal diseases, and selecting disease-resistant or tolerant cultivars.</p> Signup and view all the answers

Plants lack an immune system like animals, but have evolved various defense mechanisms to protect themselves from pathogens.

These are pre-existing barriers in the plant that physically block pathogens from entering.

These are defense mechanisms that are present in the plant before infection occurs.

These are defense mechanisms that are triggered by infection and are formed after the pathogen has entered the plant.

A waxy layer that covers leaves and fruits, preventing water from entering and acting as a barrier to pathogen entry.

A tough outer layer of epidermal cells that can resist penetration by pathogens.

Thickened cell walls composed of lignin that provide mechanical support and block pathogens.

Natural openings on leaves and stems that allow gas exchange but are potential points of entry for pathogens. The size and structure of these openings can affect disease susceptibility.

These are layers of cork cells formed after infection to block the spread of pathogens and limit the damage.

Gaps formed between infected and healthy cells, causing the infected area to shrivel and fall off, taking the pathogen with it.

Overgrowths of plant cells that protrude into xylem vessels, blocking the flow of water and nutrients and preventing the pathogen from spreading.

Sticky substances produced by plants that trap and immobilize pathogens, preventing them from spreading.

A sheath of callose (a carbohydrate) formed around invading hyphae, limiting their spread.

These are chemical compounds produced by plants that can directly kill or inhibit pathogens.

These are chemical compounds produced by the plant before infection occurs and are stored in plant cells.

Substances released by the plant into its environment that inhibit pathogen growth. These can be sugars, amino acids, enzymes, or other compounds.

These are compounds directly present within plant cells that exhibit antimicrobial activity and can be toxic to pathogens.

Antimicrobial compounds produced by plants in response to infection or injury. They can be produced in large quantities quickly and are effective against a variety of pathogens.

A localized cell death triggered by the plant in response to pathogen invasion. This prevents the pathogen from spreading further.

Proteins produced by plants that have antimicrobial activity and can inhibit the growth of pathogens.

A process by which a plant becomes resistant to a wide range of pathogens after being exposed to a specific pathogen. This resistance is often systemic, meaning it affects the entire plant.

A process by which a plant becomes resistant to a specific pathogen after being exposed to a non-pathogenic microorganism. This resistance is often localized and triggered by specific chemical signals.

The study of the outbreak of disease, its course, intensity, and causes, and the factors that influence its spread.

A disease that occurs regularly in a specific area and is expected to continue to do so.

A sudden outbreak of disease that affects a large geographic area and causes significant damage to crops. It is characterized by a rapid spread and severe consequences.

A disease that spreads over multiple continents or subcontinents and causes widespread mortality. It is a global phenomenon with potentially devastating consequences.

A disease that occurs irregularly in a limited area and is not expected to become widespread.

A model used to describe the interaction between host, pathogen, and environment in disease development. The length of each side of the triangle represents the influence of each factor on the occurrence of disease.

A model used to explain the multiple factors involved in disease development, including host, pathogen, environment, time, and human activities. It is represented as a pyramid with each corner representing a key factor.

A model used to predict the occurrence and severity of a plant disease based on the interaction of host, pathogen, and environmental factors. It helps farmers make informed decisions about disease management practices.

A type of disease forecasting model that relies on past experience and observations to predict disease occurrence. It is often used in conjunction with simple rules or guidelines.

A type of disease forecasting model that uses scientific understanding of disease development to create accurate predictions. It involves detailed research and analysis of key factors.

A type of disease forecasting model that simulates disease development using computer programs. It accounts for multiple factors, including time, and allows for different scenarios to be modeled.