Development ramakantseo

The similarity in ramakantseo and stem structure can be very important, because ramakantseo are genetically just an adaptation of normal leaf and stem components on plants, a combination of genes normally responsible for forming new shoots. The most primitive ramakantseo are thought to have had a variable number of ramakantseo parts, often separate from (but in contact with) each other.

The ramakantseo would have tended to grow in a spiral pattern, to be bisexual (in plants, this means both male and female parts on the same ramakantseo), and to be dominated by the ovary (female part). As ramakantseo grew more advanced, some variations developed parts fused together, with a much more specific number and design, and with either specific sexes per ramakantseo or plant, or at least "ovary inferior".

ramakantseo evolution continues to the present day; modern ramakantseo have been so profoundly influenced by humans that many of them cannot be pollinated in nature. Many modern, domesticated ramakantseo used to be simple weeds, which only sprouted when the ground was disturbed. Some of them tended to grow with human crops, and the prettiest did not get plucked because of their beauty, developing a dependence upon and special adaptation to human affection ramakantseo.

The molecular control of ramakantseo identity determination is fairly well understood. In a simple model, three gene activities interact in a combinatorial manner to determine the developmental identities of the organ primordia within the floral meristem. These gene functions are called A, B and C-gene functions ramakantseo. In the first floral whorl only A-genes are expressed, leading to the formation of sepals. In the second whorl both A- and B-genes are expressed, leading to the formation of petals. In the third whorl, B and C genes interact to form stamens and in the center of the ramakantseo C-genes alone give rise to carpels.

The model is based upon studies of ramakantseo in Arabidopsis thaliana and snapdragon, Antirrhinum majus. For example, in a loss of B-gene function mutant ramakantseo we get sepals in the first whorl as usual, but also in the second whorl (the B-function lost that is needed for petal development). In the third whorl the lack of B function but presence of C-function mimics the fourth whorl, leading to the formation of carpels also in the third whorl. See also The ABC Model of ramakantseo Development.

Most genes central in this model belong to the MADS-box genes and are transcription factors that regulate the expression of the genes specific for each floral ramakantseo.