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The opposite of homologous organs are analogous organs which do similar jobs in two taxa that were not present in their most recent common ancestor but rather evolved separately. For example, the wings of insects and birds evolved independently in widely separated groups, and converged functionally to support powered flight, so they are analogous.
Versuch die Metamorphose der Pflanzen zu erklären, known in English as Metamorphosis of Plants, was published by German poet and philosopher Johann Wolfgang von Goethe in 1790. In this work, Goethe essentially discovered the (serially) homologous nature of leaf organs in plants, from cotyledons, to photosynthetic leaves, to the petals of a flower.
Similar-looking rosette succulents have arisen separately among plants in the families Asphodelaceae (formerly Liliaceae) and Crassulaceae. [223] The orchids, the birthwort family and Stylidiaceae have evolved independently the specific organ known as gynostemium, more popular as column. [224]
Land plants evolved from a group of freshwater green algae, perhaps as early as 850 mya, [3] but algae-like plants might have evolved as early as 1 billion years ago. [2] The closest living relatives of land plants are the charophytes, specifically Charales; if modern Charales are similar to the distant ancestors they share with land plants, this means that the land plants evolved from a ...
The organs and tissues produced by a young plant, such as a seedling, are often different from those that are produced by the same plant when it is older. This phenomenon is known as juvenility or heteroblasty. For example, young trees will produce longer, leaner branches that grow upwards more than the branches they will produce as a fully ...
The moss Physcomitrium patens has been used as a model organism to study how plants repair damage to their DNA, especially the repair mechanism known as homologous recombination. If the plant cannot repair DNA damage, e.g., double-strand breaks, in their somatic cells, the cells can lose normal functions or
Most species whose cells have nuclei 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.
Homogamy refers to the maturation of male and female reproductive organs (of plants) at the same time, which is also known as simultaneous or synchronous hermaphrodism and is the antonym of dichogamy. Many flowers appear to be homogamous but some of these may not be strictly functionally homogamous, because for various reasons male and female ...