Biology 240

  1. only these kind of organisms contain homeobox containing family of genes also known as hox genes
  2. Control the development of body form
    hox genes
  3. hox genes produces
    a wide variety of animal morphology
  4. What two unique cell types does an animal contain
    • nerve cells
    • muscular cells

    *unique to animals*
  5. nerve cells function
    impulse conduction
  6. muscle cell function
  7. three characters that define an animal
    • multicellular
    • eukaryotic
    • heterotrophs who ingest their food
  8. animals reproduce sexually with what stage dominating the life cycle
    diploid stage
  9. after a sperm fertalizes the egg
    what three things began to occur in the development of the animal
    • zygote undergoes cleavage
    • a blastula forms and undergoes gastrulation
    • formation of embryonic tissue layers and a gastrula
  10. some animals develop through transiet stages into an adult but another form of transition is called
  11. sexuall immature stage that is morphological distinct from the adult
  12. larva undergo
  13. larva undergo metaphorphosis meaning
    transformation of the animal into an adult
  14. It is believed that the common ancestors of living animals may have resembled
    modern choanoflagellates, protists that are the closest living relatives of animals
  15. another hypothesis about the common ancestor of living animals was
    probably itself a colonial flagellated protist
  16. early members of the animal fossil record include
    ediacaran fauna
  17. neoproterozoic era
    1 billion-524 million years
  18. marks the earliest fossil appearance of many major groups of living animals
    cambrian explosion
  19. paleozoic era
    524-251 million years
  20. 5 causes of the cambrian explosion
    • predator-prey relationships generated diversity through NS
    • pred acquired adaptations to catch prey
    • prey acquired adaptations that helped resist predators
    • raise in atomospheric oxy provided opportunities for animals with high metabolic rates and bigger bodies
    • evolution of hox genes resulted in variations in morphology
  21. mesozoic era
    251-65.5 million years
  22. two events that occured during the mesozoic era
    • dinosaurs were dominant terrestrial vertebrates
    • coral reef emergence become important marine ecological niches for other organisms
  23. cenozoic era
  24. modern mammal orders and insects
    diversified during the cenozoic era
  25. in the beginning of the cenozoic era was followed by
    mass extinctions of both terrestrial and marine animals
  26. a group of animal species that share the same level of organizational complexity is known as a
  27. the set of morphological and developmental traits that define a grade
    body plan
  28. bilateral animals have these 4 traits
    • top and bottom side
    • left and right side
    • head and tail
    • development of a head
  29. cephalization
    development of a head
  30. tissue vary according the the organization of the animals tissues
  31. collections of specialized cells isolated from other tissues by membranous layers
  32. three types of embryonic tissues
    • ecot
    • endo
    • mesoderm
  33. diploblastic animals
    triploblastic animals
    • two germ layered animals
    • three germ layered animals
  34. true body cavity that is derrived from mesoderm
  35. may or may not be present in a triploblastic animal
    body cavity
  36. body cavity that is derived from the blastocoel rather than from mesoderm
  37. organisms without body cavitites
  38. two developmental modes in animals
    • proto
    • deuterosomes
  39. cleavage in protosome
    spiral and determinate
  40. spiral in cleavage meaning
    cell division diagonal to vertical axis of the embryo
  41. radial in cleavage meaning
    cleavage is either parallel or perpendic to the vertical axis of the embryo
  42. cleavage in deutero
    radial and indeterminate
  43. determinate meaning in cleavage
    ulitmate fate of each cell is determined
  44. indeterminate cleavage meaning
    early cell retains potential to develop into a complete embryo
  45. indeterminate cleavage is repsonsible for
    what makes human identicle twins
  46. coelom formation in protostome development
    • splitting of the mesoderm to form the coelomic cavity
    • (schizocoelous development)
  47. colem formation in deuterstome development
    formation of the body cavity is called enterocoelous development
  48. current debates in animal systematics led to the development
     of two phylogenic trees
  49. the two hypothesis of the animal phylogenic trees are based on
    • morphological and developmental comparisons
    • molecular data
  50. 5 points of agreement among the animal phylogenic trees
    • animals share a common ancestor
    • sponges are basal
    • eumetazoa is a clade of true tissue animals
    • most animal phyla belong to the clade bilateria
    • vertebrates and other phyla belong to clade deuterostomia
  51. in the morphological based tree the bilaterians are
    divided into two clades, proto and deutero
  52. in recent molecular data bilaterians are
    generally assigned two sister taxa to the protosomes rather than one

    (ecdysozoans and lophotrochozoans)
  53. the idea of preformation in the 18th century was thought that
    • the embryo contained all of the descendants as smaller embryos
    • (russian doll)
  54. Besides the russian nesting doll hypothesis, another preformation hyposthesis was that
    the sperm contained a preformed infant which grows (homunculus)
  55. form of an animal emerges gradually from a relatively formless egg
  56. epigenesis was a theory proposed by
  57. a cell with the potential to become a new individual
    diploid cell
  58. fertilization is not a single event but begins when the egg and sperm first come into contact
  59. 4 events of fertilization
    • contact between sperm and egg
    • regulation of sperm entry into the egg (prevents other sperms from enetering)
    • fusion of genetic material
    • activation of egg metabolism to start embryonic development
  60. this type of sperm is unable or is poorly able to fertilize
    freshly ejaculated
  61. before sperm becomes able to fertilize it must undergo changes known as
  62. capacitation occurs while a sperm resides in the female reproductive tract for a period of time. The function of capacitation
    destablize the sperms membrane to prepare it for acrosome reaction
  63. clade bilateria contains these three clades
    • lophotrochozoa
    • ecdysozoa
    • deuterstomia
  64. lophotrochozoa is named this due to
    lophophore for feeding
  65. lophotrochozoa includes these 6
    • flatworms
    • rotifers
    • ectoprocts
    • brachiopods
    • molluscs
    • annelids
  66. flatworms are known as the phylum
  67. platyhelminthes live in these three environments
    • marine
    • freshwater
    • damp terrestrial habitats
  68. bilaterian animals have bilateral symmetry and _______ development
  69. are acoelomates and undergo triploblastic development
  70. the protonephridia in the flatworms function
    regulate the osmotic balance
  71. platyhelminthes 4 description
    • triploblastic
    • aceolomate
    • central nervous system
    • bilateral symmetry
  72. free living flatworms that are mostly marine, predators, and scavengers
  73. two types of platyhelminthes that are parasitic
    • trematodes
    • monogeans
  74. trematodes are parasites in ______
    and their hosts are ______
    • humans
    • snails
  75. are parasites of fish
  76. trematoda type
    cestoda type
    • flukes
    • tape worms
  77. scolex function on tape worm
    attatch to hosts intestine
  78. habitat of rotifers
    • fresh water
    • ocean
    • damp soil
  79. smaller than many protists
    organ systems are specialized
  80. rotifers have an alimentary canal which functions as
    digestive tube with a seperate mouth and anus, lies within a fluid filled pseudocelom
  81. parthogenesis
    females reproduce offspring from unfertilized eggs
  82. a horse shoe shaped suspension feeding organ with ciliated tentacles
  83. lophophorates include two phyla known as
    • ectoprocta
    • brachiopoda
  84. are colonial animals that resemble plants
  85. ectoprocts contain an exoskeleton which functions as
    encases the colony
  86. resemble molluscs but two halves of the shell are dorsal and ventral instead of lateral like in clams
  87. multicellular organisms are divided into three grades
    • eumetazoa
    • parazoa
    • mesozoa
  88. are multicellular but lack the germ layers of the eumetazoa
    • parazoa
    • mesozoa
  89. these multicellular organisms are entirely parasitic but have a complex reproductive cycle
  90. this phylum of multicellular organisms are composed of two layers of epithelia with fluid and fibrous cells between them
  91. phylum porifera organism
  92. porifera means
    pore bearing
  93. are sessile and depend on water currents to bring them food
  94. organism has no organs or tissue and their cells are independent
  95. extend back to the cambrian or earlier
  96. four characteristics to sponges
    • heterotrophic
    • multicellular
    • asymmetrical
    • lack true tissues
  97. five types of phylum porifera
    • encrusting
    • boring
    • tube
    • finger
    • vase
  98. body opening of sponges consist of incurrent pores aka
  99. flagellated collar cells line the canals of the sponges
  100. how choanocytes use their flagella in the sponges
    keeps current flowing
  101. choanocytes trap and phagocytize food particles passing by
  102. the framework of the sponge is composed of
    needle like calcareous or siliceous spicules or spongin fibers
  103. three types of canal systems
    • asconoid
    • leuconoids
    • syconoid
  104. simplest canal system of sponges
  105. chaonocytes lines the ______ in the sponge
  106. how does water enter and exit the sponge
    water enters through the ostia and exits through the osculum
  107. this kind of canal system is only found in tube shaped calcarea
  108. canal system contains tubular body and singular osculum like asconiods
  109. the walls of this canal system are folded to form choanocyte lined canals
  110. most complex canal system that permits an increase in sponge size
  111. in this canal system the choanocytes line the walls of small chambers where they filter water
  112. the canal systems of most sponges
  113. sponge cells are arranged in a gelatinous matrix called
  114. two types of cells in sponges
    • archeocyte
    • pinacocyte
  115. form pinaderm and are flat epithelial like cells
  116. three characteristics of archaeocytes
    • move about in the mesohyl
    • phagocytize particles in pinacoderm
    • differentiate into any different type of cells
  117. sclerocytes secrete
  118. spongocytes secrete
  119. collencytes secrete
  120. lophocytes secrete
    collagen but they look like collencytes
  121. spicules are composed of calcium carbonate
    vase shaped
    all types of canal systems
  122. three characteristics of class hexactinellida
    • deep sea forms
    • lack pinacoderm or mesohyll
    • chambers correspond to leuconoid and syconoid
  123.  spicles are six rayed and made of silica
    class hexactinellida
  124. four characteristics of class demospongiae
    • spicules are siliceous
    • spicles are bound together by spongin
    • all leuconoid
    • mostly marine
  125. a class of sponges without a skeleton or siliceous spicles without an axial filament
  126. are found throughout the intracellular matrix of the sponges
    collagen fibrils
  127. dempsongiae secrete what kind of spiricles
  128. rigid skeletons of sponges consist of these two types of spiricles
    • calcareous
    • siliceous
  129. sponges are made from these three materials
    • silica
    • calcium carbonate
    • spongin
  130. sponge structure spiricles could be arranged in two ways
    haphazard or precise
  131. a small sponge such as a leuconia has approx
    81000 incurrent canals
  132. large sponges can filter _____ of water a day
    1500 liters
  133. 80% of chaonocytes phagocytize particles that are filtered
  134. digestion in sponges are completely done _____ by the cells _______
    • intracellular
    • archaeocytes
  135. how do sponges reproduce
    • asexual
    • sexual
  136. sponges can be hermaphrodites but at different times called
  137. gametes can be derived from what two structures
    • chaonocytes
    • archaeocytes
  138. the two types of reproduction a sponge undergoes
    wht kind of sponges do this
    • oviparious- release into water
    • vivparious- fertilize inside
    • demos and calcarea
  139. two ways class calcarea and demospongiae has an unsual developmental pattern
    • flagellated cells become choano and archaecytes
    • large cells become pinacocytes
  140. have no symmetry, no muscular or vascular organs
  141. how to placozoans eat
    glide over food and secrete disgestive enzymes and absorb nutrients
  142. cell layers of the placozoa
    dorsal and ventral epithelium
  143. the ventral epithelium of the placozoa contains these two types of gland cells
    monciliated and nonciliated
  144. dorsal epithelium and the ventral epithelium of the placozoa represents
    • ectoderm
    • endoderm
  145. this phyl animals are diploblastic, have agastrovascular cavity and a single opening
  146. four classes of phylum cnidaria
    • hydrozoa
    • scyhozoa
    • cubozoa
    • anthozoa
  147. example of
    • man of war and hydra
    • jellies and sea nettles
    • box jellies
    • sea anemones and corals
  148. two types of cnidaria body plans
    • polyp
    • medusa
  149. phylum ctenophora type of animals
    comb jellies
  150. five characteristics of phylum ctenophora
    • plates of fused cilia
    • prey capturing cells
    • delicate
    • transparent
    • non stinging predators
  151. three orders of ctenophora
    • cydippida
    • beroida
    • lobata
  152. have long streactable tentacnles
    globular shape and develop comb rows
  153. ctenophora cylindircal flattened body with no tentacles
    order beroida
  154. ctenophora flattened body with oral lobes and shortened tentacles
    order lobota
  155. true muscles of the ctenophores make up a
    muscular antagonostic system
  156. how to ctenophores move
    comb rows composed of ctenes are used for swimming
  157. where in the ctenophores does the elastic supportive cell are contained
  158. ctenes are coordinated by
    apical sense organs
  159. how to cteno feed themselves and the function
    colloblasts-have sticky adhesive to capture prey
  160. sheaths retract the tentacles of the ctenophores
  161. the transition of the foods from the ctenophore opening to end
    • mouth opens to stomodeum with enzymes
    • stomach leads to gastrovascular canals
    • aboral canal leads to anal canals
    • which ends in anal pores
  162. sometimes ctenophores use mucus on the body to trap food, they get the food to their mouths by
    ciliated grooves on oral lobes
  163. ctenophores reproduce
    • asexually
    • sexually
  164. four characteristics of cteno reproduction
    • hemaphrodite
    • endodermal gonads
    • external fertilization
    • unsual cell division
  165. embryos of ctenophores develop into
    cydippid larvaer
  166. touch coat that covers ecdysozoans
  167. the cutcile of ecydzo are shed or molted by a process called
  168. two largest phyla
    • nemo
    • arthro
  169. many nematodes can be short or long and parasiticq
  170. how do nematodes use their pseudocoelom
    as a hssq
  171. fluid filled cavity in which only mesoderm lines the outer edge of the developing blastoceol
  172. what does a nematoda body use to resist the high hydrostatic pressue exterted by fluid in the pseudo
    a thick cuticle made up of collagen that is secreted by the underlying epidermis
  173. beneath the epidermis of the nematoda is a layer of
    longitudial muscles
  174. antagonistic role in nematodes is not in the muscles but
    by the cuticle
  175. nematodes have what kind of disgetive tract
  176. are nematodes mono and dioecious
  177. nematodes fertilize internally and go through several developmental stages
  178. free living nematodes live in what habitats
    all environments
  179. what four things to free lving nema eat
    • carnivrores
    • algae
    • fungi
    • plants (roots)
  180. ascarids
    hook worms
    trichina worms
    pin worms example of what kind of phylum
    parasitic nematodes
  181. large round worm of humans that occurs when parasite eggs are eaten
    ascaris lumbricoides
  182. how does acaris affect humans
    • penerate the intestinal wall and travel through the blood stream to the lungs
    • they make their way up the trachae where they are swallowed
    • after swallowed the settle in small intest
  183. how do hook worms affect
    • large plates help them to cut through intestinal loning
    • pumps blood through its gut, partial digest, then excerte
  184. hook worms do no attach to one spot in the gut but move around and reattach when ready to feed
  185. no cure for this kind of parasitic nematodes
    guinea worms
  186. a tiny nematode called trichinella spirallis causes a fatal disease called ______ and how does it form
    • trichinosis
    • living in cysts in the muscle of the hosts
  187. thread like nematodes which can inhabit different locations of the body such as abdominal cavitiy
    filarial worms
  188. are picked up by mosquitos, then when they infect another person the young are released into the blood and lymphatic system
    filarial worms
  189. elephantiasis may develop when this kind of worm live in the lymphatic system
  190. how does filarial worms cause elephantiasis
    blockage of lymphatic ducts and inflammation
  191. arthropods date back all the way to the
    cambrian explosion
  192. the arthropod body plan consists of these three
    • segmented body
    • hard exoskeleton
    • jointed appendages
  193. arthropod evolution is characterized by these two
    • decrease in # of segments
    • increase in appendage specialization
  194. arthropod body is covered by _____ and an exoskeleton made up of two layers of
    • cuticle
    • protein and polysacc chitin
  195. type of circulatory system arthropods have
  196. the fluid that circulates into the surrounding spaces of open circulatory system
  197. earliest form of cheliceriforms
  198. most modern cheliceriforms are known as
  199. four characteristics of the arachnid body plan
    • abdomen
    • cephalothorax
    • six pairs of appendages
    • anterior are chelicerae
  200. gas exchange in spiders occurs in respiratory organs called
    book lungs
  201. insect and plant diversity declined during the cretaceous extinction but began increasing 65 million years since
  202. two types of names of species in which are a part of crustaceans
    • isopods
    • decapods
  203. marine terrestrial and freshwater species of crustaceans
  204. large crustaceans such as lobsters, crabs, shrimp etc
  205. planktonic crusteceans which are among the most numerous of all animals
  206. are a group of crustaceans that are sessile
  207. two types of deutero
    • echinoderm
    • chordates
  208. slow moving sessile creatures that are marine animals
  209. these two echinoderms have no arms but 5 rows of tube feet
    • sea urchins
    • sand dollars
  210. lack spines, very reduced endoskeleton and look very different from other echinoderms
    sea cucumber
  211. soft bodied animals protected by a hard shell
  212. three main parts of mollsuscs
    • muscular
    • visceral mass
    • mantle
  213. where are the mollsucs gonads located
    visceral mass
  214. many molluscs life cycles include a ciliated larval stage called
  215. oval shaped marine animals encased in an 8 dorsal armor plates, reduced cranial, and radula enforced with iron
  216. chiton is an example of what kind of mollusca class
  217. nudibrach have 3 characteristics for being molluscs
    • no shell
    • gills
    • nematocysts discharge (dorsal projections)
  218. mollsucs of the class bivalvia examples
    • clams
    • oysters
    • mussles
  219. mantle cavity of the bivalve contains gills that function as these two
    • feeding
    • gas exchange
  220. 6 characteristics of the class cephalopoda
    • shell is absent of vestigial
    • jet propulsion
    • ink sac
    • foot is arms and tentacles
    • marine
    • pedators
  221. how to octopi move
    • craw
    • eject water from siphon
  222. cephalopods have what kind of circulatory system
  223. shelled cephalopods
  224. cephalopods that are extinct
  225. three phylum of annelids
    • oligochaeta
    • polychaeta
    • hirudinea
  226. type of annelid named for their sparse chatae and bristles made of chitin
  227. class of annelids have paddle like parapodia that work as gills and aid in locomotion
  228. leeches are a part of hirudinae because
    they secrete a chemical called hirundin to prevent blood from coagulating
  229. the cuticle of ecdysozoans is shed or molted by a process called
  230. the tough coat ecdyso are covered by
  231. nematodes use their pseudocoelom as
  232. a fluid filled body cavity in which mesoderm lines only the outer edge of the developing blastocoel
  233. nematodes body has a thick cuticle secreted by the underlying epidermis, which resists the high hs pressure exerted by the fluid in the psuedo
  234. beneath the epidermis of the nematodes if a layer of
    longitudial muscles
  235. antagonistic roles in nematodes is not in the muscles but in the
  236. nematodes have a complete gut
    fertilization is internal
    most free living nema are carnivorous
    hook worms move around the gut, not only in one spot
  237. guinea worms (think of dream pulling it out)
    filarial causes elephantitis
  238. three parts of the arthropod body plan
    • segmented body
    • jointed appendages
    • hard exoskeleton
  239. changes in arthropod evolution may be caused by hox gene sequence of regulation
  240. an exoskeleton of arthropods made of protein and ploysaccharide chitin
  241. type of circulatory of arthropods
  242. earliest cheliceriforms were
  243. 4 features of the arachnid
    • abdomen
    • cephalothorax
    • six pairs of appendages
    • anterior chelicerae
  244. myriapods 2 examples
    • millipede
    • centi
  245. myriapods are terrestrial and have jaw like
  246. flight is the key to great success of insects
  247. two types of crustaceans
    • iso
    • decapods
  248. mostly sessile crusteaceans
  249. shared characteristics that define deuterostomes (chordates and echinoderms)
    • radial cleavage
    • anus then mouth
  250. lack spines, very reduced endoskeleton, and do not look like regular echinoderms
    sea cucumbers
  251. the most successful group of animals
  252. are bilaterian animals that belong to the clade of animals known as deuterostomia
  253. the two groups of invertebrate deuterostomia that are most closely related to veterbrates than the inverts
    • urochordates
    • cephalocordates
  254. 4 characters of chordates
    • noto
    • hollow dorsal nerve cord
    • post anal tail
    • pharyngeal slits
  255. longitudial flexible rod between the digestive tube and nerve cord
  256. provides skeletal support throughout most of the length of the chordate
  257. nerve cord of the chordate develops from a plate of ______ that rolls into a tube dorsal to the noto
  258. grooves in the pharynx that develops into slits that open to the outside of the body
    pharyngeal slits
  259. three functions of pharyngeal slits
    • feeding
    • gas exchange
    • develops into head
  260. marine suspension feeders that retain characteristics of the chordate body plan as adults
  261. named for their bladelike shape
  262. are more closely related to other chordates than are lancelets
  263. urochordata example
  264. are marine suspension feeders commonly called sea squirts
  265. 4 characteristics of craniates
    • skull
    • brain
    • eyes
    • sensory organs
  266. craniates have 2 clusters of hox genes
    tunicates and lancelets have 1
  267. one feature unique ti craniates
    neural crests
  268. a collection of cells near the dorsal margins of the closing neural tube in an embryo
    neural crest
  269. hagfish have these two but lack these two
    • cartilaginous skull 
    • axial rod of cartilage derived from the notochord

    • jaws
    • vertebrate
  270. vertebrates have 3 derived characters
    • vertebrate enclosing a spinal cord
    • elaborate skull
    • fin rays
  271. represent the oldest lineage of vertebrates
  272. cartilaginous segments surrounding the notochord and arching partly over the nerve cord
  273. vertebrates that have jaws
  274. huge modified lysosome that is packed with zona digesting enzymes
  275. where is acrosome located on a sperm
    anterior part of the sperms head
  276. provides the sperm with an enzymatic drill to get through the zona pellucida
    acrosome reaction
  277. these two events expose the acrosomal contents, leading to leakage of acrosomal enzymes from the sperms head
    • membrane fusion
    • vesiculation
  278. as the acrosome reaction progresses and the sperm passes through the zona pelludica, more and more of the plasma membrane is lost
  279. once the sperm penetrates the zona it does what
    binds to and fuses plasma membrane of the oocyte
  280. prior to fertilization what state is the egg in
    second meitotic divion in metaphase
  281. upon binding of a sperm the egg undergoes a number of metabolic and physical changes called
    egg activiation
  282. three events that occur in egg activation
    • rise in intracellular concentration of Ca
    • complete second meiosis
    • cortical reaction
  283. massive exocytosis of cortical granules seen after sperm and egg fuse
    cortical reaction
  284. the proteases from the cortical granules alter the structure of the zona pellucida
    zona reaction
  285. critical importance of the zona reaction is
    represents the major block to polyspermy in most mammals
  286. the block to polyspermy results in two measurable changes incuded in the zona pellucida
    • ZP hardens
    • sperm receptors in the ZP are destroyed
  287. 4 stages of development
    • cleavage
    • pattern
    • differentiation
    • growth
  288. cleavage ends with the formation of a
  289. the activities of the cleavage are controlled by
    • the mothers genome
    • mrna and proteins she deposited in the unfertilized egg
  290. during cleavage the cells arrange themselves into a ball called ______ with the cell layer surrounding the fluid filled anterior _____
    • blastula (blastocyst)
    • blastocoel
  291. yolk settles to the bottom of the egg producing
    a gradient of stored material
  292. cells produce by cleavage organize themselves in layers and masses
  293. a process that occurs in patterning
  294. the cells of the embryo ______ to form the specialized structurs and functions that they will have as an adult
  295. various regions of the germ layers develop into rudimentary organs
  296. notochord forms from
    neural plate forms from
    • meso
    • ecto
  297. neural plates curves inward to form
    neural tube
  298. neural tube will become CNS
  299. mesoderm lateral to the noto forms blocks called
  300. four extraembryonic membranes
    • chorion
    • amnion
    • yolk sac
    • allantois
  301. chorion
    yolk sac
    allantois function
    • gas exchange
    • amniotic fluid
    • encloses yolk
    • disposes of waste products
  302. a group of cells that develops into the embryo and forms the extraembryonic membranes
    inner cell mass
  303. the outer epithelium of the blastocyst
  304. three things that form the placenta
    • trophoblast
    • mesodermal cells from the epiblast
    • endometrial tissue
  305. study of evolutionary developmental processes in a multicellular organism
    evo devo
  306. are bilaterian animals that belong to the clade of animals known as deuterostomia
  307. longitidual flexible rod between the digestive tube and nerve cord
  308. function of notochord
    provides skeletal support throughout most of the length of a chordate
  309. in vertebrate a more complex skeleton develops and the adult retains only reminants of the notocord
  310. the nerve cord of a chordate embryo develops from a plate of
  311. the nerve cord develops into
  312. function of pharyngeal slits
    • suspension feeding
    • gas exchange
    • develops into parts of the neck and head
  313. the post anal tail of chordates contains skeletal elements and muscles
    provides propelling force in many aquatic animals
  314. are marine suspension feeders that retain characteristics of the chordate body plan as an adult
  315. more closely related to other chordates than are lancelets
  316. urochordata
  317. tunicates resemble chordates during their larval stage. Larval tunicates are mobile, swim about with open mouths
  318. craniates opened up a completely new way of feeding for chordates called
    active predation
  319. 4 characters of craniates
    • skull
    • eyes
    • brain
    • sensory organs
  320. craniates have two clusters of hox genes
    lancelets and tunicates have only one cluster
  321. unique feature to craniates
    neural crests
  322. collection of cells near the dorsal margins of the closing neural tube in an embryo
    neural crest
  323. neural crest gives rise to a variety of structures such as
    bones and cartilage of the skull
  324. fossils from the cambrian explosion 530 million y.a document the transition to craniates
  325. the least derived surviving craniate lineage is
    myxini (hag fish)
  326. during the cambrian, a lineage of craniates evolved into vertebrates
    they become more efficent at capturing food and avoid being eaten
  327. represent the oldest lineage of vertebrates
  328. have cartilaginous segments surrounding the notochord and arching partly over the nerve cord
  329. are vertebrates that have jaws
  330. jaws of gnathostomes derived from
    pharyngeal slits
  331. feature that evolved for another purpose
  332. have a skeleton composed of primarily cartilage
  333. evolved secondarily from an ancestral mineralized skeleton
  334. largest and most diverse group of chondrichthyans
    sharks, rays, etc
  335. 4 characteristics of sharks
    • streamline body
    • carnivores
    • spiral valve
    • acute sense
  336. fusiform body shape
    • pointed leading edge
    • maximum depth 1/3 body length
    • posterior taper
    • caudal fin
  337. eggs are produced and retained inside the mother and the shells disappears and young are retained until fully developed
    yolk sac viv
  338. mother secretes nutrient rich fluid which is taken up through the skin of the embryo
    uterine viv
  339. young in each oviduct consume unfertilized eggs or other siblings
    cannibal viv
  340. nutrients are supplied to the embryo directly from the mother via the umbilical cord
    placental viv
  341. majority of vertebrates belong to a clade of gnathostomes called
  342. bony fish
  343. have a bony endoskeleton
  344. actinopterygii example
    ray finned fishes
  345. fins of ray finned fishes fins are modified for what 2 things
    • maneuvering
    • defense
  346. ray finned fishes fins are supported mainly by
    long flexible rays
  347. dipnoi example
  348. 3 characteristics of lungfish
    • lungs and gills
    • low oxygen in water, goes to gills
    • fins
  349. are gnathostomes that have limbs
  350. one of the most significant events in vertebrate history was when these two events occurred
    lobe fins evolved into the limbs and feet of tetrapods
  351. three orders of amphibians
    • urodela
    • anura
    • apoda
  352. amphibians have moist skin that complements the lungs in gas exchange
  353. a group of tetrapods whose living members are reptiles
  354. amniotes are named for the major derived character of the clade
    amniotic egg
  355. contains membranes that protect the embryo
    amniotic egg
  356. first major group of reptiles to emerge ______ are mostly large, stocky, herbivores
  357. as parareptiles were dwindling, the diapsids were diversifying
  358. diapsids consists of two main lineages
    • lepido
    • archo
  359. lineage has tuataras, lizards, and snakes
  360. this lineage produced the crocodilians, pterosaurs, and dinosaurs
  361. dinosaurs that are bipedal carnivores
  362. fossil discoveries and research have led to the conclusion that they were fast moving and agile
  363. when do dinosaurs become extinct
    end of the cretaceous
  364. survivng lineages of lepido is represented by two species of lizard like reptiles called
  365. are the most numerous and diverse reptiles apart from birds
  366. turtles have a boxlike shell made of upper and lower shields that are fused to the vertebrate, clavicle, and ribs
  367. are archosaurs that has undergone modification in their adaptation to flight
  368. many characters of birds are adaptations that facilitate flight
  369. the major adaptation of birds is
    wings (keratin)
  370. 4 adaptations of birds
    • lack bladder
    • one ovary
    • small gonad
    • loss of teeth
  371. 3 ways flight helps with birds
    • hunting
    • escape from predators
    • migration
  372. birds are said to be descended from small theropods
  373. archaeopteryx
    oldest bird known
  374. living birds belong to the clade
  375. flightless birds
    penguins, ducks, ducks
  376. are amniotes that have hair and produce milk
  377. 4 derived characters of mammals
    • produce milk
    • hair
    • large brain
    • differentiated
  378. the three living lineages of mammals that emerged by the early cretaceous
    • monotremes
    • marsupials
    • eutherians
  379. convergent evolution
    several unrelated species have evolved to share a similar characteristic. eg penguins and seals have similar body shape for swimming performance, bats and birds have wings etc.
Card Set
Biology 240
midterm #2