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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.
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord.The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts.
Chloroplasts in leaf cells of the moss Mnium stellare. Plant anatomy or phytotomy is the general term for the study of the internal structure of plants.Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal rosette of leaves in the first year and then flower and fruit in the second year. bifid Forked; cut in two for about half its length. Compare trifid. bifoliate
Nerves that exit from the brain are called cranial nerves while those exiting from the spinal cord are called spinal nerves. The nervous system consists of nervous tissue which, at a cellular level, is defined by the presence of a special type of cell, called the neuron. Neurons have special structures that allow them to send signals rapidly ...
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 ...
Plants may bear either all bisexual flowers (hermaphroditic), both male and female flowers (monoecious), or only one sex (dioecious), in which case separate plants are either male or female flower-bearing. Where both bisexual and unisexual flowers exist on the same plant, it is called polygamous.
This helps form the precursors needed for certain organs and the embryo to develop. In summary, the notochord plays essential roles in embryonic development. The notochord provides a directional reference to the surrounding tissue as a midline structure during embryonic development , acts as a precursor for vertebrae and a primitive axial ...