are horse hoofed leg and bat wing homologous.analogous,or homoplastic?
960125
An analogous structure is one that serves the same purpose in two different species, but evolved seperately instead of from the same embryological origin.\nA homologous structure is one that is shared by two species thanks to a common ancestor. \nA homoplastic structure is one that is similiar in two species, but do not share a common ancestor\nyour case would be homologous, as a horse hoof and a bat wing are both esentially modifications of the hand of the animal.
724046
no such - the phrase can be found as - advanced mammal like reptile or advanced mammal studies\n\nbut since it is homework then your teacher is probably looking for something like HUMAN as in an advanced ( on an evolutionary scale ) mammal ( teachers can be wrong too )
814580
Evolution of the aortic arch system has been one of progressive deletion and substitution, accompanied by a reorientation or rerouting of the blood supply.\nThe greatest changes in the system occurred in the transition from the holoaquatic to the terrestrial habit, with deletion of the first, second, and finally the fifth pairs of arches. Associated with these deletions, and the development of the pulmonary circulation, was reduction and atrophy of the dorsal portion of the\nsixth arches. Subsequently, evolution of the system has resulted in atrophy of one of the radices aortae (left in birds and right in mammals), loss of the left systemic arch in birds, and loss or functional modification of the right systemic arch in mammals.\nStill further changes and deletions in this system are found to occur in the birds.\nOf very common occurrence is reduction or loss of the dorsal portion of either the left or right 3rd aortic arch, accompanied by fusion of the dorsal carotids, anterior to the carotid arch (unicarotid condition). In a few instances, however, both left and right dorsal carotids become reduced to ligamentous vestiges (ligamentiottleyi) and cephalic blood flow is carried by the vertebral and superficialcervical arteries. In such instances, the dorsal portions of both left and right carotid arches become obliterated.\nWith loss of the left systemic arch, the left ductus caroticus loses its posterior connection, and usually becomes functionally modified. In most instances this is followed by a similar disconnection of the right ductus caroticus. The latter, however, frequently retains its connection between the carotid and systemic arches and remains as a patent vessel.\nRecent studies on 810 species and subspecies of birds have revealed the following, rather interesting, fact. In a single specimen of Megapodius freycinet layardi,\nand over 30 specimens of the Trochilidae, both left and right systemic (4th aortic) arches were lacking. In each of these instances, it was apparent that the right ductus caroticus remained as the functional systemic arch which carried the blood\nsupply to the abdominal aorta. Such a condition is not to be regarded as totally unexpected in the course of evolution of the aortic arch system, although it has not, to the writer's knowledge, been reported previously.\nThe particular significance of the occurrence of this reduction in Megapodius and among the Trochilidae cannot be satisfactorily evaluated at this time. It seems to me to be significant that the Trochilidae appear to present a highly uniform occurrence\nin the deletion of the right systemic arch, particularly in view of their rather restricted distribution. Evolution of this family of birds probably centered in\nSouth America, after an earlier origin from the common Apode stock in Antarctica.\nInsular isolation of Megapodius layardi may have been a factor contributing to the evolution and deletion of the right systemic arch in this specimen. It has not, however, been ascertained to what extent this deletion may occur in this species, but\nfurther studies might reveal the expected frequency of occurrence.\nIn conclusion, it may be expected that, in the course of evolution of the aortic arch system of birds, only the proximal or ventral portions of the 3rd aortic (carotid) ancl 6th aortic (pulmonary) arches and the right ductus caroticus will remain as the\nfunctional portions of the embryonic aortic arch system. The major cephalic blood supply will then be carried by the vertebral and superficial cervical arteries, while the blood supply to the abdominal region will be carried by the ductus\ncaroticus and abdominal aorta.
378634
Chickens' legs bend the same way as ours do. However, it may appear the opposite because the joint that we can see outside its body is the ankle and not the knee. \nThe femur of birds is relatively short and is inside the body, thus it's not visible. The second segment of the leg is a composite of their tibia and some tarsal bones, and it articulates with the third segment, formed by other tarsal bones fused to the metatarsals. \nHere's a picture of a bird skeleton:\nhttp://www.infovisual.info/02/img_en/056%20Skeleton%20of%20a%20bird.jpg\nAnd a photograph of a real one:\nhttp://a-s.clayton.edu/biology/biol3650l/skeletal/bird/bird-lateral.jpg\n\nNow, the next time you have chicken (or turkey) for dinner, you can have a little dissection entertainment! Bear in mind that the parts of the leg that you eat are the first segment (the largest one, you'll see the femur that was articulated to the axial skeleton) and the second segment (the tibiotarsus, also fleshy because of the muscles). \nIn contrast, the third segment (tarsometatarsus) does not have muscles, but tendons that go from the muscles to the fingers. This part is usually covered with scales and is not included in commercially prepared chickens.\n\nHave fun!
906731
One of its feet are both the same.
167611
To the above mention person, idiot this is english if you are not versed in scientific terms don't go spouting nonsense. Cartilages are not true bone material, they are soft tissue like what our noses and most non skeletal fishes such as sharks and rays are composed of. But a toad has a skeletal structure and the cartilages are the same as a humans, found at the bridge of the nose area.
855593
I would look here for your answer and/or a link that could get you your answer http://en.wikipedia.org/wiki/Vertebrate\n\nGood Luck!!!
247179
The answer to your question is twofold:\n\nThe bone structure of birds is indeed very different from that of mammals and other non-flying vertebrates. Their bones have a resistant outer layer, but the inner part is mostly hollow and in many cases invaded by the air sacs (part of the respiratory system). Therefore they're structurally different.\n\nOn the other hand, the structure of a bird's skeleton is different from mammals too. They have some fusions of bones that contribute to their stability and rigidity, and their hands have only 3 fingers. Their skull has no sutures, most have a keeled sternum and very different vertebrae.
1167866
Gray Myotis, Howell's Bat\n\nCheck this site:\nhttp://www.animalinfo.org/species/bat/myotgris.htm\n\nIt has a picture and answers all of your questions. It has maps.
714268
skeletal(striated)\nsmooth \ncardiac
1173306
I haven't heard of the appendix specifically being used as an example of an evolutionarily signifigant vestigial structure, however scientists have long used the presence of vestigial structures (such as tail bones in humans) to imply shared ancestry with other animals which posess a functional version of the structure, in other words, a homologous structure.   Any basic college-level biology textbook should give an adequate description of the evidence for evolution if you want more information.
681143
chiropterophily (pollination by bats)
34428
Richard Dawkins attempts to answer this : \n[The embryo of every 4-limbed  vertebrate has five "fingers and toes".]\n"We tend to think that  the possession of 5 digits is deeply stamped in the hands and feet  of tetrapods (4-limbed  vertebrates).  Yet {some early vertebrates] had  7 toes....8 toes....6 toes. ...My tentative guess is that\nin those early times the different species really did benefit from their respective numbers of toes...Later the tetrapod limb design hardened at 5 digits because some internal embryonic  process came to rely upon that number. In the adult the number is frequently reduced...in..modern horses to just one, the middle toe."
930589
believe it or not...bats are most closely related to primates!
243055
We have a horny (keratin) protection on our last phalanxes because we're mammals and almost all mammals have (except for whales and some others); it's something we probably inherited from our synapsid ancestors ("mammal-like reptiles"). \nAnd we have fingernails instead of claws or hooves because we're primates. All great apes have fingernails, whereas "lower" primates have claws. \n\nAt least, that's the evolutionary reason. I'm sorry if you were looking for something more philosophical!
819951
Of course - they are mammals!  This site refers to relevant issues for reference:\n\nhttp://www.hedgehogworld.com/content/view/26/42/
139588
Maria, \n\nBirds are bipedal, warm-blooded, oviparous vertebrates characterized primarily by feathers, forelimbs modified as wings, and hollow bones. I will attach some links to follow for your question as it is a very detailed one.