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In humans, the vermiform appendix is sometimes called a vestigial structure as it has lost much of its ancestral digestive function. Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. [1]
Anatomy photo:37:12-0102 at the SUNY Downstate Medical Center—"Abdominal Cavity: The Cecum and the Vermiform Appendix" "The vestigiality of the human vermiform appendix: A Modern Reappraisal"—evolutionary biology argument that the appendix is vestigial; Smith HF, Fisher RE, Everett ML, Thomas AD, Bollinger RR, Parker W (October 2009).
Ileum, caecum and colon of rabbit, showing Appendix vermiformis on fully functional caecum The human vermiform appendix on the vestigial caecum. The appendix was once believed to be a vestige of a redundant organ that in ancestral species had digestive functions, much as it still does in extant species in which intestinal flora hydrolyze cellulose and similar indigestible plant materials. [10]
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.
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Areoles represent highly specialized branches on cacti. They evolved as abortive branch buds while their spines evolved as vestigial leaves. [2] In branched cacti, such as Opuntioidiae and the saguaro, new branches grow from areoles, because that is where the buds are. The development of the areole seems to have been an important element in the ...
Diagram of an anther in cross section. 1: Filament; 2: Theca; 3: Connective (the conducting vessels in red); 4: Pollen sac (also called sporangium) The androecium is one of the fertile cycles of flowers. The parts that make up the androecium are called stamens whose function is the generation of male gametophytes or pollen grains.
After flowering, most plants have no more use for the calyx which withers or becomes vestigial, although in a few plants such as Lodoicea and eggplant (Solanum melongena) the calyx grows along with the fruit, possibly to protect the attachment point. Some plants retain a thorny calyx, either dried or live, as protection for the fruit or seeds.