Definition of terms

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M

Name Description Related terms
macrogranule

A granule of particle size range from 2 to 6 millimetres (mm).

macronutrients

The elements required in large amounts by plants. They include carbon, nitrogen, oxygen, hydrogen, potassium, calcium, magnesium, phosphorus and sulphur. The term is used to distinguish these nutrients from those required by plants in micro or trace amounts.

macroorganisms

Organisms visible to the unaided eye.

macrophytes

Plants visible to the naked eye.

Main panel

The most prominent panel on a label on an agvet chemical product. The main panel generally contains the signal heading, the distinguishing name of the product, the active constituent statement and the contents statement.

major change

A change to a registered product or its label that is expected to require data for technical assessment of potential risks to safety of humans, the environment, the host crop or animal; to efficacy or to Australian trade. Technical assessment may be required of data for toxicology, occupational health and safety, residues and trade, environment, efficacy or host crop or animal safety.

major export food commodity group

Major export food commodity group has the same definition as that in the Agricultural—Overseas trade (Part 5B) Regulatory Guideline.

major food crop

Any crop that is widely consumed in Australia by humans or livestock, and includes (crop group—individual crops):

  • grasses—barley, maize, oats, rice, sorghum, triticale, wheat, sugarcane
  • citrus fruit—oranges, mandarins
  • pome fruit—apples, pears
  • stone fruit—apricots, plums, peaches, nectarines, cherries
  • berries and other small fruit—grapes (wine and table), strawberries
  • assorted tropical and subtropical fruit (inedible peel)—avocados, bananas, mangoes, pineapples
  • bulb vegetables—onions
  • brassica vegetables—broccoli, cabbages, cauliflowers
  • fruiting vegetables (cucurbits)—melons, pumpkins, cucumbers
  • fruiting vegetables (other than cucurbits)—peppers (capsicums), mushrooms, tomatoes
  • leafy vegetables—lettuce
  • legume vegetables and pulses—beans (French and runner), chickpeas, field peas, green peas, lupins
  • root and tuber vegetables—carrots, potatoes
  • stalk and stem vegetables—asparagus
  • tree nuts—almonds, macadamias
  • oilseeds—cotton, canola, sunflowers
  • pastures grown specifically for the purpose of being grazed by, or fed to, livestock—lucerne, medics, clovers and grasses, whether for grazing or seed crops.
major food-producing animal

Cattle (meat and milk), sheep, pigs and chickens (meat- or egg-producing) are major food-producing animal species.

major formulation change

for the purposes of agency assessment (toxicology, OH&S, environment, residues)

A change to the formulation of an agricultural or veterinary chemical product. This includes new combinations of existing active constituents that may require separate assessment of the safety to humans, the environment and/or target species. Some examples are:

  • where there has been a significant increase in the concentration of the active constituent that could affect the hazard potential, poison scheduling, safety directions or residues
  • where a major change in non-active constituent significantly affects the performance, stability or other attributes of the product
  • where the formulation has been changed significantly to accommodate a new application method or use pattern (eg a change from a wettable powder to an emulsifiable concentrate; a change from an oral drench to a topical pour-on dosage form).
  • for the purposes of efficacy and safety assessment A change to the formulation of an agricultural or veterinary chemical product. This includes new combinations of existing active constituents that require assessment for efficacy and/or safety to the host crop or animal. Some examples are:
  • where there has been a significant change in the concentration of active constituent and where the application or dose rate to the crop or animal is changed
  • where a major change in non-active constituent significantly affects the performance, stability or other attributes of the product
  • where there has been a significant change in product specifications
  • where the formulation has been changed significantly to accommodate a new application method or use pattern (eg a change from a wettable powder to an emulsifiable concentrate; a change from an oral drench to a topical pour-on dosage form)
  • where the new formulation is not identical, not closely similar, and not similar to a registered reference product.

Major changes in formulation are expected to require assessment under Module 8.1. However, applicants may provide valid scientific argument regarding submission of relevant efficacy or safety data to justify a different level of assessment. For example:

  • if the change in formulation is likely to affect only efficacy or safety, then assessment under Module 8.3 could be appropriate
  • if demonstrating comparable efficacy or bioequivalence with the previous formulation, data could be assessed under Module 8.3.
major metabolite

Metabolites comprising 100 micrograms per kilogram (µg/kg) or more, or 10 per cent or more of the total residue in a sample collected from the target animal species in a metabolism study.

malignant

Tending to become progressively worse and to result in death.

Mantel Haenszel test
manufacture

From s. 3 of the Agvet Code:

In relation to a chemical product, means:

  1. to produce the chemical product, or
  2. to engage in any part of the process of producing the chemical product, or any component or ingredient of the chemical product as part of that process, or of bringing the chemical product to its final state, including by formulating, processing, assembling, packaging, labelling, storing, sterilising, testing, supplying or releasing for supply.

From s 3 of the Agricultural and Veterinary Chemical Products (Collection of Levy) Act 1994:

Includes formulate.

manufactured food
manufacturer's specifications (MS)

A statement of the description of the active constituent, including the maximum and minimum limits of purity, the maximum limits of contaminants, the test for identity and any other properties, as applicable. The manufacturer's specification is signed and dated by the manufacturer. Certificates of analysis and safety data sheets do not constitute a manufacturer's specification.

Manufacturers' Licensing Scheme (MLS)

An APVMA quality assurance program whose primary objective is to assure, and give confidence in, the quality of veterinary medicines manufactured and supplied in Australia.

Manufacturers' Licensing Scheme Industry Liaison Committee (MLS-ILC)

The key consultative forum between the APVMA and peak chemical industry organisations representing manufacturers of veterinary chemical products.

manufacturing concentrate

A form of an active constituent that contains intentionally added inert ingredients, such as stabilisers or solvents. The manufacturing concentrate is intended for further formulating and repackaging to become an agvet chemical product.

manufacturing principles

From s. 3 of the Agvet Code:

Means principles that the APVMA has determined under section 23 of the Agricultural and Veterinary Chemicals Act 1994 to be principles to be observed in the manufacture of chemical products.

Manufacturing Principles [Agricultural and Veterinary Chemicals Instrument No. 1 (Manufacturing Principles) 2007]

From s. 3 of the Agvet Code:

Means principles that the APVMA has determined under section 23 of the Agricultural and Veterinary Chemicals Act 1994 to be principles to be observed in the manufacture of chemical products.

A legal instrument that describes the principles that the APVMA has determined, under section 23 of the Agricultural and Veterinary Chemicals Act 1994 , to be the principles that must be observed in the manufacture of chemical products.

Manufacturers must comply with the Manufacturing Principles to be issued with a manufacturing licence and to retain that licence under the Agvet Code .

manufacturing scale production

Manufacture at the scale typically encountered in a facility during normal operation.

manufacturing site, manufacturing premises

The physical location of the site where any step in a manufacturing process is conducted, including manufacture of the active constituent, manufacture of agvet chemical products, testing, etc.

margin of exposure (MOE)
margin of safety

The margin between the health-based guidance value (reference dose) and the actual or estimated exposure dose or concentration. For some experts, the margin of safety has the same meaning as the margin of exposure.

marker residue

The residue whose concentration is in a known relationship to the concentration of total residue in an edible tissue.

The parent agvet chemical or any of its metabolites, or a combination of any of these, with a known relationship to the concentration of the total residue in each of the various edible commodities at any time between administration of the agvet chemical product and depletion of the residues to permitted levels.

marker vaccine

A vaccine preparation that allows (serological) distinction between vaccinated and infected animals.

market authorisation

Includes active constituent approvals, product registration (including listed registration), or permits issued by the APVMA providing access for agricultural or veterinary chemicals to the Australian marketplace.

marketed product label

The marketed product label is the label that is attached to or printed on the product container. It includes all components of the label suite, such as the immediate container label, outer container label and leaflet.

masking
mass medication

A treatment that is applied to a substantial number of animals in one herd or flock, whether administered at the one time or over a period of time.

master document

A document from which copies are made for use in the manufacture or testing of individual batches of product. The master document is checked, authorised and filed until required for copying.

Master seed

A microorganism at a specific passage level which has been selected and permanently stored by the producer and from which all other seed passages, such as the production seed, are derived.

master seed lot (MSL)

A homogeneous suspension of the original cells or organisms on which production of an immunobiological product is based and aliquoted into individual containers for storage. For genetically modified products, the cells in the MSL are normally already transformed by the expression vector containing the desired gene. In some cases, the MSL for the expression vector and MSL for host cells may be distinct.

Material Safety Data Sheet (MSDS)
matrix

The basic edible animal products (eg tissue, milk, egg, honey) that contain or could contain the residue of interest.

mats
maximum dosage

The largest amount of an agvet chemical product that can be used safely, without excess residues or damage occurring to whatever is being treated.

maximum residue limit (MRL)

The maximum concentration of a chemical residue that is legally permitted in, or on, a food or food commodity or animal feedstuff when that chemical is applied according to good agricultural practice or good practice in the use of veterinary drugs. The MRL is expressed in milligrams of the residue per kilogram of the commodity or food (mg/kg) or in milligrams of the residue per litre (mg/L) in a liquid commodity.

maximum residue limit standard (MRL standard)

From s. 3 of the Agvet Code:

Means the maximum residue limit standard, made under the Food Standards Australia New Zealand Act 1991, as in force from time to time, or any standard in force in substitution for that standard.

mean

A measure of central tendency, the arithmetic average.

A statistic used primarily with interval—ratio variables following symmetrical distributions.

Measure of potency
Measure pack

A sealed container that contains a measured quantity of chemical product for use on one occasion. One or more measure packs may be enclosed in a pack.

mechanical agitation

The stirring, paddling or swirling action of a device, which keeps a pesticide and any additives thoroughly mixed in a spray tank.

mechanical incorporation

Being thoroughly mixed with the top layer of soil by mechanical cultivation.

median

A measure of central tendency, the value of the case marking the midpoint of an ordered list of values of all cases.

A statistic used primarily with ordinal variables and asymmetrically distributed interval—ratio variables.

median lethal concentration

See 'LC50 or LC50'.The concentration of a substance that kills 50 per cent of a population of experimental organisms within a specified period. The median lethal concentration is usually expressed in milligrams per litre (mg/L) or milligrams per kilogram (mg/kg) as a concentration in food, water or air.

median lethal dose

See 'LD50 or LD50'. The dose of a substance that kills 50 per cent of a population of experimental organisms within a specified period. The median lethal concentration is usually expressed in milligrams per kilogram of body weight (mg/kg).

medical practitioner

From r. 3 of the Agvet Code Regulations (unless the contrary intention appears):

Means a person registered or licensed as a medical practitioner under a law of a state or territory.

medicinal plant

A botanical plant whereof the whole, or a part, is used for pharmaceutical purposes.

medium volume spray

A spray used at the rate of 170 to 770 litres per hectare (L/ha).

meets the application requirements

From s. 3 and s. 8A of the Agvet Code:

An application meets the application requirements if:

  1. the application:
    1. is in writing in the approved form, and
    2. is signed by the applicant, and
    3. is accompanied by so much of the prescribed fee as is required to be paid when the application is made, and
    4. is lodged with the APVMA, and
    5. contains, or is accompanied by, any information specified for the application under section 8B [of the Agvet Code ], and
  2. the constituent, product or label in relation to which the application is made complies, or will comply, with any requirement prescribed by the regulations, and
  3. any requirement made under section 157 or 159 [of the Agvet Code ] in relation to the application has been complied with, and
  4. any requirement prescribed by another provision of [the Agvet] Code in relation to the application has been complied with, and
  5. any amount (including an amount in respect of a tax or penalty) that is payable by the applicant to the APVMA (including under a law of another jurisdiction or the agvet law), has been paid.
meets the efficacy criteria

From s. 3 and s. 5B(1) of the Agvet Code:

A chemical product meets the efficacy criteria if use of the product, in accordance with instructions approved, or to be approved, by the APVMA for the product, is, or would be, effective according to criteria determined by the APVMA by legislative instrument or contained in an established standard.

meets the labelling criteria

From s. 3 and s. 5D(1) of the Agvet Code:

A label for containers for a chemical product meets the labelling criteria if the label contains adequate instructions relating to such of the following as are appropriate:

  1. the circumstances in which the product should be used
  2. how the product should be used
  3. the times when the product should be used
  4. the frequency of the use of the product
  5. the withholding period after the use of the product
  6. the re-entry period after the use of the product
  7. the disposal of the product when it is no longer required
  8. the disposal of containers of the product
  9. the safe handling of the product and first aid in the event of an accident caused by the handling of the product
  10. any matters prescribed by the [Agvet Code] regulations.
meets the safety criteria

From s. 3 and s. 5A(1) of the Agvet Code:

An active constituent or chemical product meets the safety criteria if use of the constituent or product, in accordance with any instructions approved, or to be approved, by the APVMA for the constituent or product or contained in an established standard:

  1. is not, or would not be, an undue hazard to the safety of people exposed to it during its handling or people using anything containing its residues, and
  2. is not, or would not be, likely to have an effect that is harmful to human beings, and
  3. is not, or would not be, likely to have an unintended effect that is harmful to animals, plants or things or to the environment.
meets the trade criteria

From s. 3 and s. 5C(1) of the Agvet Code:

A chemical product meets the trade criteria if use of the product, in accordance with instructions approved, or to be approved, by the APVMA or contained in an established standard, does not, or would not, unduly prejudice trade or commerce between Australia and places outside Australia.

member of staff

From s. 3 of the Agvet Code:

In relation to the APVMA, has the same meaning as in the Agricultural and Veterinary Chemicals (Administration) Act 1992 .

mesophilic

A description of a class of bacteria that grow optimally at moderate temperatures (between 25˚C and 40˚C).

metabolism

The enzymatic conversion of one compound to another in living organisms.

metabolite

A chemical resulting from the biological transformation of another chemical.

metabolites of interest

The parent compounds of veterinary drugs or their metabolites that were demonstrated in the edible tissues of the food-producing animal and have relevance to the toxicological acceptable daily intake established for the veterinary drug.

metamorphosis

Change from one shape, form or structure to another.

The process of insect development, which includes the egg, larva, pupa (chrysalis) and adult stages. The entire process is sometimes referred to as complete metamorphosis.

metastasis

The spread of cancer from one organ or tissue site to another.

method validation

The process of proving that an analytical method is acceptable for its intended purpose.

methodology

The way in which information is found or something is done. The methodology includes the methods, procedures and techniques used to collect and analyse information.

metrology

The science of measurement.

micro-emulsion

A clear to opalescent oil-in-water emulsion containing liquid, to be applied directly or after dilution in water, when it may form a diluted micro-emulsion or a conventional emulsion.

The APVMA formulation type code for a micro-emulsion is MC.

microbial breakpoint

The antibiotic concentration above which organisms are known, or very likely, to harbour a resistance mechanism.

microbial control

The use of naturally occurring organisms such as bacteria, fungi and viruses to control insects.

microbial pesticide

A pesticide that has an 'active constituent' that is a microorganism, bacterium, virus or other tiny plant or animal. Examples include Bacillus thuringiensis and nuclear polyhedrosis virus.

microcapsule suspension

A suspension in which the solid particles consist of a toxicant(s) that is encased in a biodegradable polymer film, which allows a slow release of the toxicant(s).

microclimate

The climate in a very small area, such as found within a crop or pasture. Each crop has its own microclimate that is determined by the type of crop.

microflora

The group of very tiny plants that includes algae, fungi, bacteria, yeasts and related microscopic organisms.

microgranule

A granule of a particle size range ranging between 0.1 and 0.6 millimetres (mm).

micronised

Reduced to a particle size that can be measured in micrometres. Usually refers to dusts or powders produced on a particular type of grinding mill actuated by compressed air.

micronucleus

A particle in a cell that contains microscopically detectable nuclear DNA; it might contain whole chromosome(s) or a broken centric or acentric part(s) of chromosome(s). The size of a micronucleus is usually defined as less than one fifth, but more than one twentieth of the main nucleus.

micronutrients

The chemical elements required by plants or animals in trace amounts to maintain normal growth and development. They include iron, copper, manganese molybdenum, boron and zinc. Cobalt is a minor element required by animals, but not by plants.

Also known as 'trace elements'.

Microorganism

Any organism that can be seen only with the aid of a microscope.

microscopic insects
mildew

A plant disease in which a causal fungus forms a coating over the surface of plant parts. Also used to describe the fungus causing such a disease.

minimum drift

A term used in spraying to describe techniques using machinery or formulations that give a high proportion of larger droplets in the spray with little drift from smaller droplets.

minimum inhibitory concentration (MIC)

The lowest antibiotic concentration that visibly inhibits the growth of microorganisms after in vitro incubation, at a time when an untreated culture becomes readily visible in or on culture medium. The MIC is usually expressed in terms of results for 90 per cent (MIC90) or 50 per cent (MIC50) of the isolates tested.

minimum tillage

A cultivation system that involves the retention of stubble. The majority of weed control is undertaken by the use of herbicides during the fallow, with no more than one mechanical cultivation.

minimum toxic dose
minor element
minor food-producing animal

Animal species that are not major food-producing animal species, but may be minor contributors to human diets, including buffalo, deer, fish (other than ornamental fish), goat, kangaroo, rabbit, bee, crustacean and mollusc.

minor formulation change

A formulation change that is not a major formulation change.

Minor use

From s. 3 of the Agvet Code and r. 3 of the Agvet Code Regulations:

In relation to a chemical product or an active constituent, means a use of a product or constituent that would not produce sufficient economic return to an applicant for registration of the product to meet the cost of registration of the product, or the cost of the research to support registration for the product for that for that use, as the case requires (including, in particular, the cost of providing the data required for that purpose).

minor-use crop

A crop that is grown on a small area and therefore uses amounts of pesticides that are too small to justify standard pesticide registration.

miscible

Two or more liquids that can be combined together to produce a mixture that remains uniform and does not settle out into layers under normal conditions.

mist blower
mist spray

The dispersion of droplets that are 50 to 100 micrometres in diameter.

mist spraying

A method in which a concentrated spray is atomised into a high-velocity air stream, the air acting as a diluent and a carrier.

mites

Tiny animals that are members of the order Acarina and closely related to insects. They have eight jointed legs, two body regions, no antennae and no wings. The nymphal stage has six legs. Mites are often grouped with tick and spiders.

miticide

A pesticide for killing mites.

mob

Group of sheep currently being treated; not necessarily all the sheep on a property.

mobility (of a pesticide)

The ability of a pesticide to move within the environment.

A factor in the consideration of the transport of the chemical and its degradation products. Several physicochemical properties are important in the prediction of mobility and permitting estimation of the distribution of the chemical through environmental compartments. Volatility, adsorption or desorption and leaching are the most important of these.

mode of action

The manner in which an agricultural or veterinary chemical product controls a pest or has its effect.

The ways in which pesticides affect people and other animals.

Active constituents are grouped by their mode of action for the purposes of managing resistance. Codes for the various modes of action appear on the labels of pesticides.

mode of administration

The method (procedure or practice) by which a chemical is applied (administered, given) to the host, target, subject animal (eg by gavage, in feed, as bait, by injection (parenteral), topically, by inhalation).

modified basal bark treatment

Using an oil-water emulsion to spray the lower parts of a plant, with emphasis on stems rather than foliage; the added oil aids penetration and improves control of tolerant species when this method is used.

modular assessment fee

From r. 3, r. 70A of the Agvet Code Regulations (unless the contrary intention appears):

  1. Schedule 7 [of the Agvet Code Regulations] sets out the assessment modules that may be necessary to determine an application for which a modular assessment fee is payable.
  2. An assessment module may have different levels or types of assessment.
  3. The fee payable for a module, level or type of assessment mentioned in an item in Schedule 7 [of the Agvet Code Regulations ], in relation to an application, is as follows:
    1. f or an application lodged on or after 1 July 2014 and before 1 January 2015—the fee (if any) mentioned for the item in column 3 of Schedule 7 of the Agvet Code Regulations ]
    2. for an application lodged on or after 1 January 2015—the fee (if any) mentioned for the item in column 4 of Schedule 7 [of the Agvet Code Regulations ].
  4. The modular assessment fee for an application is the sum of the fees payable for:
    1. the preliminary assessment module in item 1 in Schedule 7 [of the Agvet Code Regulations ], and
    2. the other modules, levels and types of assessment that the APVMA considers necessary for the application to undergo, and
    3. the type of finalisation assessment module in items 11.1 to 11.3 in Schedule 7 [of the Agvet Code Regulations ] that the application must undergo.

Note: The Agricultural and Veterinary Chemicals Code Instrument No. 2 (Modular Assessment Fees) 2010 sets out criteria for working out which modules, level and types of assessment apply in a particular case.

[Management of modular assessment fees for re-categorised applications is prescribed in r. 70B of the Agvet Code Regulations .]

modular assessment period

From r. 3, r. 77 of the Agvet Code Regulations (unless the contrary intention appears):

  1. In addition to setting out the fees for modules, levels and types of assessment, Schedule 7 [of the Agvet Code Regulations ] sets out in Column 3 of the Schedule the period within which some of those modules, levels and types must be completed.
  2. The modular assessment period referred to in Column 2 or Column 3 of an item in Part 2 of Schedule 6 [of the Agvet Code Regulations ] (that is, the period within which an assessment of an application must be completed) is the sum of:
    1. the longest of the periods for such other modules or levels of assessment in other items in Schedule 7 [of the Agvet Code Regulations ] that the APVMA considers necessary for the application to undergo, and
    2. the period for the type of finalisation assessment module in items 11.1 to 11.3 in Schedule 7 [of the Agvet Code Regulations ] that the application must undergo.
module

Module means the module of assessment, including its level or type of assessment, as set out as items in the table in Schedule 7 to the Agvet Code Regulations (for example, module 2.1 is the chemistry module—level 1).

molar mass (Mm)
mollusc

Any of a large family of invertebrate animals, which includes snails and slugs.

molluscicide

A pesticide used to control snails, slugs and other molluscs.

monitoring powers

From s. 3 of the Agvet Code:

Has the meaning given by sections 131A, 131B and 131C [of the Agvet Code]. Section 131A describes monitoring powers—with consent or with warrant—that an inspector may exercise in relation to premises. Section 131B describes monitoring powers to operate electronic and certain other equipment. Section 131C describes monitoring powers relating to securing evidence of the contravention of certain offence and penalty provisions under Agvet legislation, the Crimes Act 1914 and the Commonwealth Criminal Code (see 131C(1)(b)).

monitoring warrant

A warrant issued under section 143 of the Agvet Code or a warrant signed by a magistrate under section 143B of the Agvet Code as the same kind that would have been issued under section 143. (See definition in s 3 of the Agvet Code)

monocotyledon

A plant with one cotyledon (embryonic leaf). These plants have the following characteristics that distinguish them from dicotyledons:

    the flower parts are in threes or in multiples of three.
  • they have leaves with veins running parallel, as found in grass leaves.

All grasses, palms, lilies and bulbs belong to this group.

The monocotyledons are often called grassy plants to distinguish them from broadleaved (or dicotyledonous) plants.

morbidity

The incidence of ill health or disease in a population.

mortality

The measure of the incidence or rate of death in a population.

mosaic

A plant disease caused by a virus and generally characterised by irregular light and dark green areas in the leaves.

mosquito coil

A coil that burns (smoulders) without producing a flame and releases the active constituent into the local atmosphere as a vapour or smoke. The APVMA formulation type code for mosquito coil is MC.

motile

Capable of spontaneous movement.

mottle

An irregular pattern of light and dark areas.

MoU
mould

Any fungus that produces a superficial, often woolly, growth on various types of organic matter; or the growth itself. Moulds occur most often on damp and decaying matter.

MRA
multi-category licence

From r. 3 of the Agvet Code Regulations (unless the contrary intention appears):

Means a licence issued under Part 8 of the [Agvet] Code to carry out steps in the manufacture of a veterinary chemical product mentioned in the definition of one of the following terms:

  1. category 2 licence
  2. category 3 licence
  3. category 4 licence

at the same premises as are used to carry out steps in the manufacture of veterinary chemical products mentioned in the definition of at least one other of those terms.

multicentre study

A study conducted according to a single study protocol at more than one site.

multiparous
multivariate analysis

An analysis of the relationships between more than two variables.

mummy

A dried, shrivelled fruit that is the result of some fungal disease, such as brown rot. The mummy may hang on the tree or fall to the ground, where the disease survives the winter and is a source of re-infection the following spring.

mutagen

A chemical or physical agent that induces genetic mutations.

mutagenesis

The process giving rise to the development of mutations.

mutagenic

Capable of producing a genetic change.

mutagenicity

The property of being able to induce genetic mutation, ie cause a permanent heritable change in the amount or structure of the genetic material in an organism or cell that may result in change in the characteristics of the organism or cell. The alteration may involve changes to the sequence of bases in the nucleic acid (gene mutation), structural changes to chromosomes (clastogenicity) and/or changes to the number of chromosomes in cells (aneuploidy or polyploidy).

mutate

To change. A sudden variation in one or more characteristics of an organism that marks the offspring as different from its parent stock. The offspring is called a mutant.

mutation

A permanent change in the nucleotide sequence of a genome that is transmitted through sexual or asexual reproduction, conjugation, etc.

mycelium

The vegetative body of a fungus. An aggregate of many filaments (hyphae) of the fungus that is commonly interwoven into a more-or-less felt-like mass.

mycology

The science dealing with fungi.

mycoplasma-like organisms

A group of extremely small bacteria that are similar to mycoplasmas (in that they have a cell membrane instead of a cell wall) and are the cause of many plant diseases formerly attributed to viruses