The family Asteraceae, with the original name Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown.
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation.
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA. The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences, and often a substantial fraction of junk DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome.
Sex is the trait that determines whether a sexually reproducing organism produces male or female gametes. Male organisms produce small mobile gametes, while female organisms produce larger, non-mobile gametes. Organisms that produce both types of gametes are called hermaphrodites. During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent.
Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules. Other functional regions of the non-coding DNA fraction include regulatory sequences that control gene expression; scaffold attachment regions; origins of DNA replication; centromeres; and telomeres. Some non-coding regions appear to be mostly nonfunctional such as introns, pseudogenes, intergenic DNA, and fragments of transposons and viruses.
Polyploidy is a condition in which the cells of an organism have more than one pair of (homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs of homologous chromosomes. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis; the sporophyte generation is diploid and produces spores by meiosis.
A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities.
Internal transcribed spacer (ITS) is the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript.
Crepis, commonly known in some parts of the world as hawksbeard or hawk's-beard, is a genus of annual and perennial flowering plants of the family Asteraceae superficially resembling the dandelion, the most conspicuous difference being that Crepis usually has branching scapes with multiple heads. The genus name Crepis derives from the Greek krepis, meaning "slipper" or "sandal", possibly in reference to the shape of the fruit.
The silversword alliance, also known as the tarweeds, refers to an adaptive radiation of around 30 species in the composite or sunflower family, Asteraceae. The group is endemic to Hawaii, and is derived from a single immigrant to the islands. For radiating from a common ancestor at an estimated 5.2±0.8 Ma, the clade is extremely diverse, composed of trees, shrubs, subshrubs, mat-plants, cushion plants, rosette plants, and lianas.
Taraxacum officinale, the dandelion or commondandelion, is a herbaceous perennial flowering plant in the daisy family Asteraceae. The common dandelion is well known for its yellow flower heads that turn into round balls of many silver-tufted fruits that disperse in the wind. These balls are called "clocks" in both British and American English. The name "blowball" is also used.
The Cichorioideae are a subfamily of the family Asteraceae of flowering plants. Familiar members of Cichorioideae include lettuce, dandelions, chicory and Gazania species. The subfamily comprises about 240 genera and about 2900 species. It is heterogeneous and hard to characterize except with molecular characters.
Taraxacum is a large genus of flowering plants in the family Asteraceae, which consists of species commonly known as dandelions. The scientific and hobby study of the genus is known as taraxacology. The genus is native to Eurasia and North America, but the two most commonplace species worldwide, T. officinale and T. erythrospermum, were introduced from Europe into North America, where they now propagate as wildflowers. Both species are edible in their entirety. The common name dandelion is also given to specific members of the genus.
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes.
Orobanche minor, the hellroot, common broomrape, lesser broomrape, small broomrape or clover broomrape, is a holoparasitic flowering plant belonging to the family Orobanchaceae. It is one of about 150 non-photosynthetic plants in the genus Orobanche that parasitize autotrophic plants.
Hypochaeris oligocephala is a species of flowering plant in the family Asteraceae native to the Canary Islands.
Tulipa albanica is a flowering plant in the tulip genus, family Liliaceae that is native to Albania. It was discovered near the village of Surroj in Albania in 2010. The plant is a critically endangered (CR) as it grows in an area smaller than 100 ha, surrounded by mining activities.
The Solanaceae, or the nightshades, are a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and ornamentals. Many members of the family contain potent alkaloids, and some are highly toxic, but many—including tomatoes, potatoes, eggplant, bell and chili peppers—are used as food. The family belongs to the order Solanales, in the asterid group and class Magnoliopsida (dicotyledons). The Solanaceae consists of about 98 genera and some 2,700 species, with a great diversity of habitats, morphology and ecology.
Holocentric chromosomes are chromosomes that possess multiple kinetochores along their length rather than the single centromere typical of other chromosomes. They were first described in cytogenetic experiments in 1935. Since this first observation, the term holocentric chromosome has referred to chromosomes that: i) lack the primary constriction corresponding to the centromere observed in monocentric chromosomes; and ii) possess multiple kinetochores dispersed along the entire chromosomal axis, such that microtubules bind to the chromosome along its entire length and move broadside to the pole from the metaphase plate. Holocentric chromosomes are also termed holokinetic, because, during cell division, the sister chromatids move apart in parallel and do not form the classical V-shaped figures typical of monocentric chromosomes.
