Systematics Terminology, Cheat Sheet of Botany and Agronomy

Download Systematics Terminology and more Cheat Sheet Botany and Agronomy in PDF only on Docsity! ab Xe, SYSTEMATICS TERMINOLOGY 6 1 | P a g e University: SU Systematics Terminology Term Definition Systematics The study of the diversity of organisms and their evolutionary relationships, including classification, nomenclature, and phylogenetics. Taxonomy The science of naming, defining, and classifying organisms based on their shared characteristics and evolutionary relationships. Phylogenetics The study of evolutionary relationships among organisms using genetic and molecular data to construct phylogenetic trees or cladograms. Cladistics A method of constructing phylogenetic trees based on shared derived characters (synapomorphies) to determine evolutionary relationships. Taxon A group of organisms at any rank in a taxonomic hierarchy, such as a species, genus, family, or order. Binomial Nomenclature The system of naming species using a two-part Latin or scientific name, consisting of the genus name and the species epithet (e.g., Homo sapiens). Linnaean Classification The hierarchical system of organizing and naming organisms developed by Carl Linnaeus, which includes ranks like kingdom, phylum, class, order, family, genus, and species. 4 | P a g e University: SU Systematics Terminology Type Locality The specific geographic location where a type specimen was collected, described, and designated. Apomorphy A derived or unique character or trait that sets a taxon apart from its ancestors and relatives. Plesiomorphy A primitive or ancestral character that is shared with the ancestors of a taxon and is not useful for distinguishing among closely related species. Biogeography The study of the distribution of species and ecosystems across geographic regions and their historical origins. Molecular Clock A method that uses molecular data to estimate the timing of evolutionary events and divergence among species based on the rate of genetic mutations. Infraspecific Taxa Taxonomic ranks below the species level, including subspecies, varieties, and forms, used to represent intraspecific diversity. Cladogram A branching diagram that represents the evolutionary relationships among a group of organisms but does not necessarily show time or degree of evolutionary change. Taxonomic Hierarchy The hierarchical structure of taxonomic ranks, from higher levels like kingdom and phylum to lower levels like family, genus, and species. 5 | P a g e University: SU Systematics Terminology Chemotaxonomy The use of chemical compounds and metabolites to classify and identify organisms, especially in plants. Polytomy A node in a phylogenetic tree where more than two branches emerge, indicating uncertainty or a lack of information about evolutionary relationships. Species Complex A group of closely related species that are difficult to distinguish due to hybridization, morphological similarity, or incomplete data. Protist A eukaryotic microorganism that does not fit into other major kingdoms, including diverse plant-like and animal-like protists. Morphological Species Concept A concept of defining species based on their morphological differences and similarities, which may not always reflect genetic or evolutionary relationships. Molecular Species Concept A concept of defining species based on genetic and molecular data, such as DNA sequence differences, with an emphasis on shared ancestry. Fossil Record The collection of all known fossils, providing insight into the history of life on Earth and the evolution of plants over geological time. Taxon Range The geographic or temporal distribution of a particular taxon, describing where and when it is found in nature. 6 | P a g e University: SU Systematics Terminology Natural Hybridization The process of two distinct plant species interbreeding and producing hybrid offspring without human intervention. Isozyme Different forms of an enzyme encoded by different alleles, often used in population genetics to study genetic diversity. Taxon Revision The process of reevaluating and updating the classification and names of taxa based on new scientific information and insights. Ex situ Conservation The conservation of plant species outside their natural habitat, often in botanical gardens, seed banks, or other managed environments. Ecological Niche The role and position of an organism within its ecosystem, including its habitat, food sources, and interactions with other species. Genus A taxonomic rank above species and below family, typically consisting of one or more species that share a common evolutionary origin. Family A higher taxonomic rank above genus and below order, consisting of one or more genera with shared characteristics. Order A higher taxonomic rank above family and below class, grouping related families with similarities in characteristics. 9 | P a g e University: SU Systematics Terminology Collenchyma Cells Plant cells with unevenly thickened cell walls that provide flexible structural support to growing plant parts. Sclerenchyma Cells Plant cells with thick, rigid cell walls, often dead at maturity, providing support and protection. Stamen The male reproductive organ in a flower, consisting of an anther (which produces pollen) and a filament. Carpel The female reproductive organ in a flower, comprising the stigma (which receives pollen), the style, and the ovary. Perfect Flower A flower that contains both male (stamens) and female (carpels) reproductive structures. Imperfect Flower A flower that contains either male or female reproductive structures but not both. Double Fertilization A unique process in angiosperms where two sperm cells are involved in fertilization, one fertilizing the egg and the other forming endosperm. Endosperm A nutrient-rich tissue in the seeds of angiosperms that provides nourishment to the developing embryo. 10 | P a g e University: SU Systematics Terminology Perennial Plant A plant that lives for more than two years, typically producing new growth and flowering in multiple growing seasons. Annual Plant A plant that completes its life cycle within one year, typically germinating, flowering, and producing seeds within that time. Lignin A complex organic polymer found in the cell walls of vascular plants, providing rigidity and support to plant tissues. Photosynthesis The process by which plants and other organisms convert light energy into chemical energy (usually glucose) using carbon dioxide and water. Chloroplast The organelle in plant cells responsible for photosynthesis, containing the green pigment chlorophyll. Chlorophyll A green pigment in chloroplasts that captures light energy and plays a key role in photosynthesis. Tropism The growth or movement of a plant in response to a specific stimulus, such as light (phototropism) or gravity (gravitropism). Germination The process by which a seed begins to grow into a seedling or plant under the right conditions, including water, temperature, and oxygen. 11 | P a g e University: SU Systematics Terminology Transpiration The process by which plants release water vapor into the atmosphere through small openings called stomata in their leaves. Stomata Small openings in plant leaves and stems that allow for gas exchange, including the intake of carbon dioxide and the release of oxygen. Adaptation A characteristic or trait that helps an organism survive and reproduce in its environment, often the result of natural selection. Etiolation The condition in which plants become pale, elongated, and weak due to a lack of light, typically observed in seedlings in the absence of sunlight. Leaflet A small, individual leaf-like structure that is part of a compound leaf, found in plants like clover and some palm trees. Turgor Pressure The pressure exerted by the fluid (usually water) inside plant cells, which helps maintain cell shape and rigidity. Cuticle A waxy, waterproof layer on the surface of leaves, stems, and other plant organs that reduces water loss and protects against pathogens. Apical Meristem A region of actively dividing cells at the tip of a plant shoot or root, responsible for primary growth in length. 14 | P a g e University: SU Systematics Terminology Angiosperm A group of seed-producing plants that produce flowers and enclose their seeds within a fruit. Gymnosperm A group of seed-producing plants that do not produce flowers; their seeds are typically not enclosed within a fruit. Monoecious A plant that has both male and female reproductive structures on the same individual. Dioecious A plant that has separate male and female individuals, with one bearing only male flowers and the other only female flowers. Allopatric Speciation The process of speciation that occurs when a population is divided by a geographical barrier, leading to genetic isolation and divergence. Sympatric Speciation The process of speciation that occurs within a single, undivided population due to factors like polyploidy, ecological specialization, or sexual selection. Polyploidy A condition in which an organism has more than two complete sets of chromosomes, often leading to reproductive isolation and the creation of new species. Gametophyte The haploid, multicellular generation in the alternation of generations life cycle of plants, producing gametes (sperm and eggs). 15 | P a g e University: SU Systematics Terminology Sporophyte The diploid, multicellular generation in the alternation of generations life cycle of plants, producing spores through meiosis. Homospory The production of a single type of spore that gives rise to both male and female gametophytes in plants. Heterospory The production of two distinct types of spores, microspores (male) and megaspores (female), leading to separate male and female gametophytes. Self-Pollination The transfer of pollen from the anther to the stigma of the same flower or a different flower on the same plant. Cross-Pollination The transfer of pollen from the anther of one flower to the stigma of a different flower, typically on a separate plant. Ovule The structure within a plant's ovary that contains the female gametophyte and develops into a seed after fertilization. Fruit The mature ovary of a flower, often containing seeds and serving as a means of seed dispersal. Seed Dispersal The process by which seeds are moved away from the parent plant, facilitating their growth in new locations. 16 | P a g e University: SU Systematics Terminology Anemophily Pollination by the wind, where pollen is carried by air currents to reach female reproductive structures. Entomophily Pollination by insects, where pollen is transported from flower to flower by bees, butterflies, beetles, and other insects. Ornithophily Pollination by birds, where certain bird species, such as hummingbirds, transfer pollen while feeding on nectar. Hydrophily Pollination by water, where pollen is transported through aquatic environments to reach female reproductive structures. Zoonosis The transmission of diseases from animals to humans, which may include pathogens carried by plants or plant-eating animals. Ethnobotany The study of how plants are used by different cultures, including their roles in traditional medicine, rituals, and daily life. Medicinal Plant A plant that has traditional or modern uses in treating or alleviating various medical conditions or diseases. Plant Pathology The study of plant diseases, including their causes, prevention, and control methods. 19 | P a g e University: SU Systematics Terminology Lenticel Small, corky structures on the surface of woody plants that allow for gas exchange between internal tissues and the external environment. Vascular Bundle A structure in plants that contains both xylem and phloem tissues for the transport of water, nutrients, and sugars. Symbiosis A close and long-term interaction between different species that can be mutualistic, parasitic, or commensalistic. Rhizosphere The soil region around plant roots where interactions between roots, microorganisms, and the soil environment occur. Ectomycorrhiza A type of mycorrhizal association where the fungal hyphae surround but do not penetrate plant root cells. Arbuscular Mycorrhiza A type of mycorrhizal association where the fungal hyphae penetrate plant root cells, forming branched structures called arbuscules. Mutualism A type of symbiotic relationship where both partners (e.g., plants and mycorrhizal fungi) benefit from the association. Allele A variant form of a gene, which can result in different traits or characteristics in an organism. 20 | P a g e University: SU Systematics Terminology Hybridization The process of crossing two different species or varieties, resulting in hybrid offspring with a combination of traits from both parents. Isogamy A type of sexual reproduction in which gametes (reproductive cells) are of similar size and structure. Anisogamy A type of sexual reproduction in which gametes are of different sizes, typically one larger (female) and one smaller (male). Dispersal Mechanism The method by which seeds or spores are spread away from the parent plant, which can involve wind, animals, or other means. Trophic Level The position of an organism in a food chain, indicating its position in the transfer of energy from producers to consumers. Parasitism A type of symbiotic relationship where one organism (parasite) benefits at the expense of the other (host) by deriving nutrients or resources. Nitrogen Fixation The conversion of atmospheric nitrogen (N2) into ammonia (NH3) or other nitrogen compounds by nitrogen-fixing bacteria or plants. Carbon Sequestration The capture and long-term storage of carbon dioxide (CO2) from the atmosphere, often through plant photosynthesis. 21 | P a g e University: SU Systematics Terminology Coevolution The mutual influence and adaptation of two or more species in close ecological relationships, often leading to specific adaptations. Lignification The process of converting plant cell walls into lignin, which increases their rigidity and durability, often occurring in woody plants. Pheromone A chemical signal released by plants (or animals) to communicate with other members of the same species, often used in reproduction or defense. Senescence The natural aging or deterioration of plant tissues or organs, often leading to leaf yellowing and shedding. Deciduous Plants that shed their leaves annually, typically in response to seasonal changes, such as winter or dry periods. Evergreen Plants that retain their leaves throughout the year, often adapted to persist in consistently favorable conditions. Nitrogen Cycle The biogeochemical cycle that describes the transformation and circulation of nitrogen through the Earth's ecosystems. Carbon Cycle The movement of carbon in various forms (carbon dioxide, organic matter, etc.) through the Earth's atmosphere, oceans, and ecosystems.