Terminology
The page contains some of the terminology related to plant structure that are used on this website.
Terminology
Roots that arise from a stem or leaf; not arising from the true root (radicle)
Allele
One form (of many) of a particular gene
Cell
The smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane
Centromere
The region of a chromosome to which the spindles attach during cell division
Chromatid
Each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of 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.
Specialized cells that have unevenly thickened primary walls that provide flexible support in herbaceous organs
Colonial organism
Unicellular organisms that are found connected (tethered) to one-another in nature
Companion cells
Specialized form of parenchyma that controls all of the cellular functions of a sieve element
Cells that compose the "skin" of the plant, such as the epidermis or bark
Diploid
Having two sets of chromosomes in each cell; therefore two copies (alleles) of each gene
DNA, DeoxyriboNucleic Acid,
A self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
Immature cells that can actively divide to increase size of the organism
Eukaryote
Organisms that possess organelles, such as a nucleus (e.g. plants, fungi, animals, algae)
Haploid
Having a single set of chromosomes in each cell; therefore only one copy (allele) of each gene
Homologous (of chromosomes)
Having the same structural features and pattern of genes. Being the same chromosome "number".
A portion of time in which a cell recovers from mitosis (post-Telophase), and/or prepares to enter mitosis or meiosis
Karyogamy
Splitting of just the genetic material; chromosomes replicated in interphase and then divided
Cell division which creates four haploid cells from a single diploid cell
Cell division which creates two identical cells from a single cell; growth
Anaphase: the third phase of mitosis or meiosis; chromatids begin to segregate and migrate to opposite ends of cell
Metaphase: the second phase of mitosis or meiosis; chromosomes line up on the equatorial plate and spindle fibers become visible
Prophase: the first phase of mitosis or meiosis; the nuclear envelope starts to dissolve and chromosomes condense
Telophase: the fourth and final phase of mitosis or meiosis; the cell plate forms and the nuclear envelope begins to form
Multicellular
An organism that is composed of many cells
Organism
A living creature, such as a plant, animal, or bacterium
Specialized cells that lack secondary walls, and form the bulk material of plants where storage occurs
Aerenchyma: parenchyma tissues that have abundant amounts of air spaces
Chlorenchyma: parenchyma tissues that have abundant amounts of chloroplasts for photosynthesis
Plasmogamy
Splitting of cell's cytoplasm and organelles
Prokaryote
Organisms without an organized nucleus or organelles (e.g. bacteria)
Radicle
The true root that emerges from the seed
RNA, RiboNucleic Acid
A nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information.
Specialized cells that have thick lignified secondary walls to provide rigid support in plants
Sieve cells
Phloem cells that transport sugars, usually found in pteridophytes and gymnosperms
Sieve tube elements
Phloem cells that transport sugars, usually found in flowering plants
Tracheids
Water-conducting and strengthening xylem cells, usually found in pteridophytes and gymnosperms
Unicellular
An organism that is one single cell
Vessels
Water-conducting xylem cells, usually found in flowering plants and some gnetophytes