Wednesday, 16 February 2022 12:37

Agricultural Science Grade 10 Glossary - Agricultural Science Grade 10 Study Guide

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GLOSARRY

A

  • abiotic physical rather than biological; not derived from living organisms
  • abrasion the process by which clasts and other particles are reduced in size
  • adaptation a change by which an organism or species becomes better suited to its environment
  • aeration the introduction of air into a material or substance
  • agents of erosion  water, wind and glaciers
  • agricultural policies a course or principle of action related to agriculture that is adopted or proposed by the government
  • agricultural production  the output from agriculture
  • agro-ecology the study of the relationship between the environment and agricultural plants and animals
  • agronomy the science of soil management and crop production
  • alluvial deposits when loose alluvial material is deposited or cemented into stone (lithified)
  • alluvium loose, unconsolidated (not cemented together into a solid rock), soil or sediments, eroded, deposited, and reshaped by water in some form in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel
  • amendment a change or addition to a legal or statutory (to do with the laws of a country) document
  • anaerobic absence of free oxygen
  • animal ratio the ratio of different animals, or of male to female animals in a pasture
  • annual population growth rate the rate at which the population increases or decreases in a given year, expressed as a percentage of the total population
  • artificial pasture an area with plants planted specifically for grazing
  • average annual rainfall the amount of rain (measured in millimetres or mm) that usually falls in an area in one year

B

  • biodegradable when something decomposes naturally
  • biodiversity the variety of life in the world or in a particular habitat or ecosystem
  • biological farming systems farmers use biological principles to increase their yields
  • biological matter living matter
  • biological pest control farmers use a pest’s natural enemy to get rid of it
  • biological weathering when living organisms cause rocks to decompose
  • biome a large naturally occurring community of flora and fauna occupying a major habitat
  • biosphere the part of the Earth that supports life, including oceans, lakes and rivers
  • biotic of, relating to, or resulting from living things, esp. in their ecological relations
  • bioturbation the disturbance of sedimentary deposits by living organisms
  • bivalent homologous chromosomes associated in pairs
  • breed specific variety of a species

C

  • capillary action the ability of liquid to flow against gravity, such as up a plant root
  • carbohydrates one of the five nutrients in food; used by the bodies of people and animals to get energy
  • carbon dioxide (CO2) a colourless, odourless gas produced by burning carbon and organic compounds and by respiration; it is naturally present in air (about 0,03%) and is absorbed by plants in photosynthesis
  • carcass traits       meat characteristics after slaughter
  • carrying capacity the number of animals that can be grazed on a piece of land
  • cell cycle the sequence of cell division, resting phase, cell division and so on
  • cell membrane the ‘skin’ of a cell, also known as the plasmalemma or plasma membrane
  • cell wall a non-living tissue made up from cellulose that is situated outside the cell membrane of a plant cell
  • centromere the point on a chromosome by which it is attached to a spindle fibre during cell division
  • chemical (or biological) weathering involves the direct effect of atmospheric chemicals or biologically produced chemicals in the breakdown of rocks, soils and minerals
  • chromatid each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA
  • chromatin network a network of fine threads consisting of protein, RNA and DNA
  • chromosome   a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes
  • cleavage the splitting of rocks or crystals in a preferred plane or direction
  • climate change long-term, significant change in the climate of an area or of the Earth, usually seen as resulting from human activity
  • climate the weather conditions prevailing in an area in general or over a long period
  • climax species plant species that will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed
  • colluvium loose bodies of sediment that have been deposited or built up at the bottom of a low-grade slope or against a barrier on that slope, transported by gravity
  • commensalism one organism benefits from the relationship, while the other organism is not harmed
  • commercial farming sector large-scale farming for profit
  • commercial production scientific farming on a large scale for profit
  • communal farming when animals are allowed to roam freely across the farm, without any fences and grazing camps
  • community all the plants and animals that live in a particular ecosystem
  • competition when organisms within the same ecosystem want the same resources, for example food
  • competitive edge a unique selling point; something special that can be used to sell a product
  • compost decomposed plant matter that is added to soil to increase the nutrient content of the soil; organic matter that has broken down into humus
  • condensation when a vapour changes into a liquid
  • conformation body structure and shape
  • conservation farming use of natural ecological processes to manage farms
  • conservation protecting a species
  • conserve to save and to use wisely
  • constitution a body of fundamental principles or established precedents according to which a state or other organisation is acknowledged to be governed (in South Africa, the Constitution of 1996 is the highest law in the land, and all other laws are only legal if they are allowed by the Constitution)
  • consumer price index (CPI)  measures the average changes over time of prices paid for goods and services
  • contaminants substances that decrease the quality of something and make it unhealthy
  • continuous grazing when animals graze the same area at all times of the year
  • contour a line on a map joining points of equal height above or below sea level; ploughing along the contours of the land in order to minimise soil erosion
  • conventional farming methods  methods to increase yields by using artificial additives, without considering damage to the environment
  • crop rotation growing a different crop on the same land each year for a period of three to five years
  • crossbreeding mating of two different breeds
  • cultivar a plant variety that has been produced in cultivation by selective breeding
  • cytokinesis the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells
  • cytoplasm the jelly-like fluid inside a cell, excluding the nucleus, in which all the organelles are suspended

D

  • deciduous a tree or shrub that sheds its leaves annually
  • decomposers organisms that break down dead plants and animals through a process called decay
  • deforestation the cutting down of large areas of forests
  • denitrification removal of nitrates or nitrites from soil, air or water
  • diluents a substance used to dilute another liquid (make it thinner )
  • diploid containing two complete sets of chromosomes, one from each parent.
  • DNA the abbreviation for deoxyribonucleic acid, which is the carrier of genetic information
  • drought-tolerant plants        plants that can grow with less water, and continue to grow if little rain falls
  • dual agricultural economy two separate economies, commercial and communal
  • dyke an intrusion of igneous rock cutting across existing strata

E

  • ecological farming systems using ecological and natural principles to increase yields
  • ecological pyramid a diagram to show the trophic levels in an ecosystem
  • ecological succession  when the type of plants growing in a pasture changes naturally without the interference of people
  • ecology the study of the relationships between living organisms and the environment in which they live
  • economy the wealth and resources of a country or region, especially in terms of the production and consumption of goods and services
  • ecosystem a biological community of interacting organisms and their physical environment
  • edaphic of, produced by, or influenced by the soil
  • El Niño weather phenomenon as a result of the ocean off the South American coast becoming warmer than normal
  • eluviation   the transport of soil material from upper layers of soil to lower levels by downward precipitation of water across soil horizons; this transported material is called illuvial deposit
  • endangered species       a species in danger of disappearing
  • endoplasmic reticulum a network of membranous tubules (very small tubes) within the cytoplasm of a cell
  • enzymes substances in living organisms that control chemical processes, for example digestion
  • equine family members of the family Equidae which includes horses, donkeys and zebras
  • erode when wind, water or other natural agents gradually wear away soil, rock or land
  • erosion the gradual removal of soil by wind or water; it is a natural process but can be increased by poor farming practices and deforestation
  • evaporation when a liquid changes into a gas
  • exotic breed     breed developed in another country with very different conditions
  • exotic come from some other parts of the world; not indigenous

F

  • fauna the animals of a particular region or habitat
  • feed (or food) conversion efficiency how well the animal converts protein in feed into growth
  • fertility how fruitful or productive something is
  • fibre diameter width of fibre
  • fibre length how long the fibre is
  • flora the plants of a particular region or habitat
  • floral kingdom the largest natural units determined for flowering plants
  • fodder food, especially dried hay or feed, for cattle and other livestock
  • follicle density  the number of follicles per area of skin
  • food chain a hierarchical series of organisms each dependent on the next as a source of food
  • food security the availability of enough nutritious food and people’s access to it
  • food web a system of interlocking and interdependent food chains
  • forage plant material eaten by grazing livestock
  • foreign currency money a country earns from outside the country
  • fossil fuels fuels made from coal, which is plant material that was compacted and fossilised many years ago
  • fracture the physical appearance of a freshly broken rock or mineral, especially as regards the shape of the surface formed
  • friable (soil)  easily crumbled (soil)

G

  • game an old English word for wild animals used for food; now refers to wild animals such as buck
  • gametes a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote
  • geology geology of an area refers to the origin and evolution of the materials the soil consists of, and the processes that act on it
  • germination when a seed begins to grow and put out shoots after a period of dormancy
  • global demand to do with how many goods or services are needed or wanted internationally
  • global warming  the phenomenon of the temperature of the Earth increasing due to the greenhouse effect, mainly caused by pollution
  • globalisation the process by which regional economies, societies, and cultures have become integrated through communication, transportation, and trade
  • Golgi apparatus folded membranes within the cytoplasm of most cells, involved in secretion and intracellular transport
  • grazing capacity the average number of animals that the farm can sustain over a period of time
  • grazing ecology the study of the relationship between the organisms in the ecosystem of the pasture
  • grazing system a particular grazing strategy that a farmer uses
  • green manure a plant that is sown to add nutrients and organic matter to the soil; it is ploughed into the land after a period of time
  • green paper also known as consultation documents, proposes a strategy to be implemented or sets out proposals on which the government wishes to obtain public views and opinion
  • gross domestic product (GDP) the total value of goods produced and services provided in a country during one year
  • gross value total amount earned for all products in one year
  • groundwater water that collects under the ground above a layer of rock and in cracks in the rocks
  • growth rate  the speed of animals’ growth

H

  • haploid having a single set of unpaired chromosomes
  • hardwood broad-leaved deciduous trees, such as oak, ash or beech
  • herbaceous is a plant that has leaves and stems that die down at the end of the growing season to the soil level; they have no persistent woody stem above ground; they may be annuals, biennials or perennials
  • herbicides chemicals that kill plants; farmers use herbicides to control weeds
  • homologous pairs pairing at meiosis and having the same structural features and pattern of genes
  • horticulture the art or practice of garden cultivation and management
  • humid marked by a relatively high level of water vapour in the atmosphere
  • humification converting plant remains into humus
  • humus   any organic matter that has reached a point of stability, where it will break down no further and might, if conditions do not change, remain as it is for centuries, if not millennia; the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms

I

  • illuviation the accumulation of illuvial deposit in lower levels
  • indigenous breed  breed developed locally
  • indigenous knowledge knowledge that has been handed down in communities, over thousands of years by word of mouth
  • individuals members of a population
  • industrialisation a period characterised by an increase in mechanisation and factories
  • inorganic substances that do not contain carbon
  • invader plants  plants of alien or foreign origin; weeds
  • invasive unwanted, spreading quickly in an uncontrolled way that can cause harm
  • irrigation supplying water to a crop by moving water from the source of the water to the place where the crop is growing

L

  • La Niña opposite of El Niño; weather phenomenon as a result of the ocean off the South American coast becoming cooler than normal
  • land reform changing land laws to make the situation fairer for all people; redressing previous inequalities in land distribution
  • land restitution actions to reverse injustices related to land ownership
  • leaching making a soluble chemical or mineral drain away from the soil by the action of a percolating liquid such as rainwater
  • leasehold the holding of property by lease, not ownership
  • legal framework  basic structure underlying the system of laws; such a framework creates the legal ‘space’ in which individuals and businesses can function
  • legislation the laws of a country, as determined by the law-making arm of government, such as parliament
  • legume an edible plant that grows inside a pod
  • livestock   farm animals regarded as an asset
  • loamy soil soil composed of sand, silt, and clay in relatively even concentration; loamy soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils; they are gritty, moist, and retain water easily
  • lustre the manner in which the surface of a mineral reflects light
  • lysosome an organelle in the cytoplasm of cells containing enzymes that break down or degrade substances enclosed in a membrane

M

  • management systems        how a farm is organised and run
  • market requirement what the consumer wants; standards set by the market
  • marketing a formal structured approach to selling based on analysis of the subject
  • mechanical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water, ice and pressure
  • mechanical weed control removing weeds using implements such as hoes
  • microbe a microorganism, especially bacterium causing fermentation
  • microbial related to microorganisms, such as bacteria, that cause fermentation
  • milk production the amount of milk produced by a dairy animal
  • minerals inorganic substances needed by the human body for good health
  • mitochondrion an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur; mitochondrion has a double membrane, the inner layer being folded inward to form layers (cristae)
  • monogastric animals with a single stomach
  • mulching a material (such as decaying leaves, bark, or compost) spread over the soil to enrich or insulate the soil
  • multicellular made up of more than one cell
  • multiplier effect the variety of products that can be derived from a single raw material
  • mutualism two organisms benefit from a relationship

N

  • natural pasture an area where animals graze that does not contain any plants planted by the farmer
  • natural resources resources that occur naturally in the environment; also called primary resources
  • natural selection selection of an animal by the environment for survival
  • no-tillage farming planting a crop without ploughing or digging the soil first; the crop is planted into the leaves and stems that are left over from the previous crop
  • non-renewable resources natural resources that are limited and may be used up one day
  • non-selective grazing when animals are forced to eat all the plants in the pasture, not only the palatable plants
  • nucleoplasm the jelly-like fluid in the nucleus
  • nucleus dense organelle present in most cells, typically a single rounded structure bounded by a double membrane, containing the genetic material
  • nutrients substances in food that animals and people need in order to grow and keep healthy; the minerals in soil are sometimes called plant nutrients
  • nutritive value  amount of nutrients a plant contains

O

  • orchard a piece of land planted with fruit trees
  • organ a group of tissues that have the same structure and function
  • organelles various structures in a cell, each performing a different function
  • organic farming increasing yields by using natural additives, such as compost
  • organic matter the remains of plants and animals that use the soil
  • organic substances containing carbon
  • outwash is a glacial outwash plain formed of sediments deposited by meltwater at the terminus of a glacier
  • over-grazing if more animals than the quantity indicated by the stocking rate are allowed to graze the pasture
  • oxidation   the combination of a substance with oxygen

P

  • palatable plants that animals like to eat because they are soft and tasty
  • parasitism one organism (parasite) lives on another organism (host), and the host is harmed
  • parenchyma the functional tissue of an organ as distinguished from the connective and supporting tissue
  • pedogenesis the process by which soil is formed
  • pesticides chemical poisons used to control pests and diseases
  • pH a figure expressing the acidity or alkalinity of a solution on a logarithmic scale on which 7 is neutral, lower values are more acid, and higher values more alkaline
  • photosynthesise   the process by which green plants and some other organisms use sunlight to synthesise foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product
  • physiographic refers to what the land surface looks like, or the appearance of the land surface
  • plant taxonomy the science that finds, describes, classifies, identifies and names plants
  • plantations an area in which trees have been planted for commercial purposes
  • plasmodesmata threads made of cytoplasm that go through from one plant cell to the next
  • plastid  any of a class of small organelles, such as chloroplasts, in the cytoplasm of plant cells, containing pigment or food
  • pollutants harmful substances that pollute the air, water or soil
  • pollute to put harmful substances into the air, water or soil
  • population growth the rate at which the number of individuals in a population increases
  • population the number of organisms (people or animals)
  • pores openings in a cell membrane
  • precipitation water that comes from the air; it includes rain, hail, frost, snow, dew and mist (fog)
  • predation when one organism (hunter) eats another organism (prey)
  • primary agriculture the first level of agriculture involved in the planting and cultivation of crops
  • primary, secondary and tertiary industries primary industries are concerned with obtaining or providing natural raw materials for conversion into commodities and products for the consumer (mining, agriculture or forestry); secondary industries convert raw materials provided by primary industry into commodities and products for the consumer (also known as manufacturing); tertiary industries are involved in the provision of goods and services
  • producers green plants that can make their own food through a process called photosynthesis
  • production systems farming methods (for example beef production systems are classified according to the age at which animals emanating from a production unit are sold. The production unit could be a farm or one of the enterprises in a larger undertaking. A full description of a system includes the age, mass and carcass class at which animals are marketed, as well as the breeding, management and feeding practices followed. In South Africa the most common beef production systems are weaner-, long yearling (tolly)- and two-year old (ox) systems.)
  • protein an organic compound that is an essential part of all living organisms
  • purebred bred from parents of the same breed or variety

R

  • radiation sending out rays, for example from the sun
  • reafforestation to cover an area by planting trees
  • regenerate to change back to the original, new condition
  • regulation a rule or directive made and maintained by an authority; legislation is usually implemented through regulations
  • renewable resources natural resources that can never be used up over time
  • reservoir any place where water is stored
  • resource conservation looking after natural resources (e.g. soil and water) to ensure their quality and that they are not used up or wasted (can also refer to looking after other resources, such as money and farm equipment) wisely so that they are of maximum benefit and last a long time)
  • ribosomes a minute (very small) particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells
  • RNA abbreviation for ribonucleic acid, a nucleic acid present in all living cells; its main function is to act as a messenger carrying instructions from DNA
  • rock weathering the breaking down of Earth’s rocks, soils and minerals through direct contact with the planet’s atmosphere; it includes physical, biological and chemical weathering
  • rough ER endoplasmic reticulum that contains ribosomes on its surface
  • ruminant hoofed mammals that have a stomach with four compartments; partially digested food is brought back for the animal to chew again, for example cows

S

  • salinisation to increase the salt content
  • salinity a measure of the total amount of dissolved salts in water or soil
  • scientific or evidence-based knowledge knowledge that comes from experimentation and research, and is based on verifiable evidence
  • season of use the part of the year when animals can graze the plants
  • seasonal distribution how something (e.g. rainfall) is spread out across the seasons
  • sediment particulate matter that is carried by water or wind and deposited on the surface of the land or the bottom of a body of water, and may in time become consolidated into rock
  • selective breeding  selecting specific animals for mating
  • selective grazing when animals do not graze all the plants in a pasture, but prefer certain plants
  • self-propagation able to increase itself in number or amount
  • silage grass or other green fodder compacted and stored in airtight conditions, typically in a silo, without first being dried, and used as animal feed in the winter or in periods where grazing is scarce
  • siltation when dams and rivers fill up with eroded soil
  • slow rotational grazing when the grazing area is divided into camps, one of which is grazed while the others are rested
  • small-scale farmers agricultural production for own consumption with a small surplus for trade
  • smooth ER endoplasmic reticulum that does not contain ribosomes on its surface
  • sodicity a measure of the amount of sodium-containing salts in water; it is measured using the sodium absorption ratio (SAR)
  • softwood conifers, such as pine, fir or spruce
  • soil compaction when the weight of heavy machinery compresses the soil, causing it to lose pore space; soil compaction may also occur due to a lack of water in the soil
  • soil conservation the process where we stop the degradation of soil and repair the damage so that the condition of the soil improves and is maintained
  • soil degradation any process that causes the condition of the soil to lose nutrients (degrade)
  • soil erosion  the carrying away of soil by wind or water
  • specialisation selection for a specific purpose
  • species a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding
  • stocking rate (SR) the number of animals that can graze on one hectare of land, for the grazeable part of one year, without damaging the condition of the pasture
  • strategic position relating to how an industry is set up and functioning in order to identify long-term or overall aims and interests and the means of achieving them
  • streak a long, thin line or mark of a different substance or colour from its surroundings
  • sublimation when a solid changes into a gas
  • subsistence agriculture  agricultural production at a level sufficient only for one’s own use or consumption, without any surplus for trade
  • subsistence farming when a farmer only produces enough for the use of his or her own household
  • subsoil the deeper parts of soil, beneath the topsoil
  • supply chain the chain of the product from the farm to the consumer
  • surface water water that is on the surface of the Earth, such as the water in rivers and lakes
  • sustainable able to be maintained at a certain rate or level; conserving an ecological balance by avoiding depletion of natural resources

T

  • terraces steps that are cut into the slope
  • tissue a group of cells that have the same structure and function
  • titlehold the ownership of property by title deed, a legal document
  • tonoplast   a membrane that bounds the chief vacuole of a plant cell
  • topography the arrangement of the natural and artificial physical features of an area
  • topsoil the top layer of the soil, which is usually more fertile than the lower layers of soil
  • transpiration give off water vapour through the stomata (the very small pores on the surface of a leaf)
  • trifoliate a plant that has three leaflets
  • trophic level  each step in the food chain
  • turbidity muddiness of irrigation water caused by soil particles and organic materials that are suspended in the water

U

  • unicellular made up of one cell
  • unpalatable plants that animals do not like to eat, because they are tough or have a bad taste or smell

W

  • water cycle the way in which water molecules are cycled from one reservoir to the next
  • water holding capacity ability of soil to hold water
  • water quality fitness of water for a particular use or for the maintenance of the health of aquatic ecosystems
  • watercourse a river, stream, or artificially constructed water channel
  • white paper a means of presenting government policy preferences prior to the introduction of legislation; as such, the publication of a white paper serves to test the climate of public opinion regarding a controversial policy issue and enables the government to gauge its probable impact
  • wind farm a collection of wind turbines which are used to generate electrical power through their mechanical motions as they are pushed by the wind; the energy generated by a wind farm can be fed directly into the general energy grid after passing through transformers

Z

  • zero grazing when animals are not allowed to graze outside, but are kept indoors; fodder is brought to them
  • zygote the product of fertilisation of an egg cell by a sperm cell
Last modified on Wednesday, 16 February 2022 12:49