CHAPTER 34 - STUDY GUIDE
how do most adult lampreys feed?
- parasitic lampreys feed by clamping their round, jawless mouth onto the flank of a live fish, their "host"
eutherians are also called
- placental mammals
which of the following is a characteristic of all chordates at some point in their life cycle?
- post-anal tail
how do reptile and mammal teeth differ?
- reptile teeth are consistent in size, while mammals have teeth with different shapes and sizes (heterodont)
which animals are amniotes?
- reptiles and mammals
how do hagfish defend themselves from predators?
- rows of slime glands on a hagfish's flanks will produce several liters of slime in less than a minute when attacked by a predator. the slime coats the gills of the attacking fish, sending it into retreat or even suffocating it
how many placoderm species are alive today?
- none
how do hagfish feed?
- most are bottom-dwelling scavengers that feed on worms and sick or dead fish
what are the 2 major groups of vertebrates that lack jaws?
- myxini + petromyzontida
amphibians are most closely related to
- lungfishes
which vertebrates are endothermic?
- mammals and birds
mammals are named for which distinctive gland, that produces?
- mammary glands, that produce milk for offspring
which primates have a fully opposable thumb?
- monkeys and apes
do sharks and rays have an operculum?
- no
is a penguin a ratite?
- no
how many acanthodian species are alive today?
- none
what are examples of monotremes?
- 1 species of platypus and 2 species of echidnas (spiny anteaters)
all chordates studied to date, except tunicates, share a set of
- 13 Hox genes
according to the fossil record, when did Homo sapiens first appear on earth?
- 195000 ya
fossils indicate that tuataras first appeared at least
- 220 mya
how old is the oldest known turtle fossil?
- 220 mya
frogs belong to Order
- Anura
Caecilians belong to Order
- Apoda
where on Earth do monotremes live?
- Australia and New Guinea only
which group of osteichthyans has more species right now?
- Ray-finned fishes (Actinopterygii)
salamanders belong to Order
- Urodela
what is a cloaca?
- a common chamber that has a single opening to the outside
what was Tiktaalik, and how does it help us understand evolution?
- a fossil - the skeletal structures of its fins and pelvis suggests that is could prop itself up and walk in water on its fin. since its predates the oldest known tetrapod, its feature suggest that key "tetrapod" traits such as wrist, ribs, and a neck , were in fact ancestral to the tetrapod lineage
which tunicate life stage exhibits the 4 chordate characteristics?
- a juvenile
vertebrates and tunicates share?
- a notochord and a dorsal, hollow nerve cord
what is the operculum of a fish, and what is its function?
- a protective bony flap over the gills - fishes draw out water with the help of these
how do tunicates capture food?
- a tunicate draws water in through an incurrent siphon; the water then passes through the pharyngeal slits into a chamber called the atrium and exits through an excurrent siphon. food particles are filtered from the water by a mucous net and transported by cilia to the esophagus
which of the following characteristics is shared by a hagfish and a lamprey?
- a well-developed notochord
define ectothermic
- absorption of external heat as main source of body heat - warming directly with solar energy rather than metabolic breakdown of food
what are the anatomical differences among the monotremes, marsupials, and eutherians?
- monotremes: lay eggs and lack nipples/cloaca - marsupials: complete embryonic development in pouch (marsupium)/no cloaca - Eutherians (or Placentals): embryo completes development in maternal uterus and receives nutrition from placenta/no cloaca
what are the 4 specialized membranes of the amniotic egg, and what is the function of each membrane?
- allantois: a disposal sac for certain metabolic wastes produced by the embryo - chorion: the chorion and the membrane of the allantois exchange gases between the embryo and the air - amnion: the amnion protects the embryo in a fluid-filled cavity that cushions against mechanical shock - yolk sac: the yolk sac contains the yolk, a stockpile of nutrients. other nutrients are stored in the albumen (egg white)
how does an adult lancelet capture food?
- an adult lancelet swims down to the sea floor and wriggles backward into the sand, leaving only its anterior end exposed. cilia draw seawater into the lancelet's mouth. a net of mucus secreted across the pharyngeal slits removes tiny food particles as the water passes through the slits, and the trapped food enters the intestine
what is the swim bladder of a fish, and what is its function?
- an air sac that when filled, helps fish maintain their buoyancy equal to the surrounding water - so if a fish swims to greater depths or toward the surface, where water pressure differs, the fish shuttles gas between its blood and swim bladder, keeping the volume of gas in the bladder constant)
in most osteichthyans, the skeleton is made primarily of
- an ossified (bony) endoskeleton with a hard matrix of calcium phosphate
to which of the 3 groups do humans belong?
- anthropoids
define endothermic
- capable of generating internal body heat through metabolic processes
in jawless vertebrates, the skull and vertebrae are made of?
- cartilage
in members of Chondrichthyes, the skeleton is primarily made of
- cartilage, and impregnated with calcium
which primates are most closely related to humans?
- chimpanzees
jaws first occured in which extant group of fishes?
- chondrichthyans
what is Archaeopteryx, and how does it help us understand evolution?
- considered to be the earliest known bird - it had feathered wings but retained ancestral characters such as teeth, clawed digits in wings, and a long tail - shows the link between birds and non-avian dinosaurs, and how gradually a species will become
to which living reptiles are birds most closely related?
- crocodilians
what is the largest living turtle species, and what does it eat?
- deep-diving leatherbacks - they feed on jellies
know the types of fin on a shark
- dorsal: stabilizing - pectoral: maneuvering - pelvic: maneuvering
what 2 phyla exhibit deuterostome development?
- echinodermata + chordata
what are examples of ratites, and how do they move?
- ex: ostrich, rhea, kiwi, cassowary, and emu (all flightless) - in ratities, the sternal keel is absent - the move using legs, because they cannot fly
which vertebrates are ectothermic?
- fish, amphibians, and most reptiles (excluding birds)
which primates are considered apes?
- gibonns, orangutangs, gorillas, chimpanzees, bonobos, and humans
vertebrates that have jaws are called
- gnathostomes
what are the derived characteristics of primates?
- hands and feet with the ability to grasp with digits - flat nails/skin ridges - large brain and short jaw - parental and social skills
what is the only type of bird that can fly backwards?
- hummingbird
how does an amniotic egg facilitate life on land?
- it allowed the embryo to develop on land in its own private "pond," reducing the dependence on tetrapods on an aqueous environment for reproduction
which shark structure is closest in function to a ray-finned fish swim bladder full of gas?
- its liver
if a ray-finned fish is to both hover (remain stationary) in the water column and ventilate its gills effectively, then what other structure besides its swim bladder will it use?
- its opercula
how many types of middle ear bones does a present day reptile have?
- just one, the stapes
what are examples of marsupials?
- kangaroos and koalas
which characteristics of birds are adaptations that facilitate flight?
- keeled sternum - one ovary in female, and no copulatory organ in male male, reducing body weight - no teeth, reduces body weight - beak of keratin is lightweight
which extant chordates are postulated to be most like the earliest chordates in appearance?
- lancelets
a team of researchers has developed a poison that has proven effective against lamprey larvae in freshwater cultures. the poison is ingested and causes paralysis by detaching segmental muscles from the skeletal elements. the team wants to test the poison's effectiveness in streams feeding lake michigan, but one critic worries about the potential effect on lancelets, which are similar to lampreys in many ways. why is this concern misplaces?
- lancelets live only in saltwater environments
what are the 3 main groups of living primates?
- lemurs - tarsiers - anthropoids
what are examples of eutherians?
- lemurs, monkeys, apes, wolverine, flying squirrel, humans
what are the 2 basic type of squamates?
- lizards and snakes
suppose you traveled back in time and located the first animals to have evolved feathers. you found that these animals were tree-dwelling ectotherms, able to run quickly but unable to fly. you also noticed that only males had feathers. which hypothesis of feather evolution would these data most support? feathers initially evolved in a role associated with
- sexual selection
define oviparous
- sharks that lay eggs that hatch outside the mother's body - these sharks release their fertilized eggs after encasing them in protective coats
define ovoviviparous
- sharks that retain their fertilized eggs in their oviduct. nourished by the egg yolk, the embryos develop into young that are born after hatching withing the uterus
what word means "four feet" in greek?
- tetrapods
what is believed to be the most significant result of the evolution of the amniotic egg?
- tetrapods were no longer tied to the water for reproduction
which structure of the amniotic egg most closely surrounds the embryo?
- the amnion
what is a tuatara, and where do tuataras live?
- they are lizard-like animals - today they are found on 30 islands off the coast of New Zealand
how do lamprey larvae feed?
- they are suspension feeders
what are the functions of reptile scales?
- they contain the protein keratin, and they help protect the animal's skin from desiccation and abrasion
what did the incus and malleus evolve from?
- they evolved from small bones that form the reptile jaw - incus, from quadrate bone of upper jaw - malleus, from articular bone of lower jaw
which of these statements accurately describes a similarity between sharks and ray-finned fishes
- they have a lateral line that is sensitive to vibrations
in what type of habitat did the earliest known primates live?
- they lived in forests and they were tree-dwellers
what are the 2 major clades of lepidosaurs?
- tuatara (lizard-like reptiles) - squamates (lizards and snakes)
what are the major clades of archosaurs?
- turtles, crocodilians, and birds
what is the only marsupial that is native to Florida?
- virginia opossum
how many types of middle ear bones does a present-day mammal have?
- we have 3 middle ear bones: the malleus, incus, and stapes
which derived characteristics distinguish humans from other apes?
- we standup and are bipedal - larger brain - complex actions - reduced jawbones/muscles - shorter digestive tract - 19 regulatory genes
define viviparous
- with sharks that young develop within the uterus and obtain nourishment prior to birth by receiving nutrient's from the mother's blood through a yolk sac placenta, by absorbing a nutritious fluid produced by the uterus, or by eating other eggs
what is a spiral valve, and what is its function?
- within the shark intestine is a spiral valve, a corkscrew-shaped ridge that increases surface area and prolongs the passage of food through the digestive tract
what are the 4 key anatomical characteristics of chordates?
1. notochord 2. dorsal, hollow nerve cord 3. pharyngeal splits 4. post-anal tail
the digestive tract of many sharks is proportionately shorter than that of most other vertebrates
TRUE
Actinistia
coelacanth
Amphibia
frog salamander caecilian
Myxini
hagfish
Mammalia
human platypus kangaroo whale
Petromyzontida
lampreys
Cephalochordata
lancelet
Dipnoi
lungfish
Chondrichthyes
shark ray ratfish
Actinopterygii
trout sea horse moray eel tuna
Urochordata
tunicate sea squirt
Reptilia
turtle dinosaur alligator bird snake lizard