Chapter 10 Flashcards
What types of animals belong to the phylum chordate?
Mostly vertebrates, with some invertebrates
What sorts of animal groups belong to the phylum chordate?
lancelets, tunicates, fishes, amphibians, reptiles, mammals.
What four features define a chordate?
(In the embryo stage) A hollow nerve cord, a tail, a notochord, and pharyngeal slits
What are the two invertebrate groups that are classified as chordate?
lancelets and tunicates
What are Lancelets?
small animals that capture food by filtering water through their mouths.
What are tunicates?
Tunicates are sessile and feed by filtering seawater
What is an endoskeleton?
An internal system of bones.
What is a notochord?
A flexible rod that runs along the top side of the back.
what does sessile mean?
fixed in one place, immobile
what animal groups are tetrapods?
amphibians, reptiles, birds, and mammals
T or F. To be a chordate means that you are also a vertebrate.
False. Invertebrates like the tunicates and lancelets are also chordates.
What group were the first vertebrates to evolve?
The fishes
When did fish first evolve?
540 mya
Humans belong to what domain, kingdom, and phylum?
eukaryotes, animals, chordates
nerve cord
nervous tissue that develops into the brain and spinal cord
True or False: Human embryos have tails.
True. this is a feature of all chordates.
The first chordates to speciate were which two groups?
the lancelets and tunicates
lancelets and tunicates can be encountered on land. (T or F)
False.
True or False. Tunicates and lancelets do not have backbones or skulls.
True.
Hagfishes have a spine, but exists only as an evolutionary remnant as an adult. (T or F)
True
What are hagfishes used for in human society?
They are hunted for fake leather.
What do both lampreys and hagfishes lack?
they both lack jaws.
The second major branch of the phylogenetic tree of chordates is the evolution of ________
chordates that are vertebrates.
What is the third major evolution in the chordate phylogenetic tree?
Chordates with jaws.
What were the first jawed vertebrates to evolve?
The cartilaginous fishes.
What is the main feature of all cartilaginous fishes?
A flexible backbone made of cartilage.
Also, fins for swimming and a strong tail.
What are two modern cartilaginous fishes?
Sharks and stingrays.
The fourth major development in the phylogenetic tree chordate is the development of organisms with ________
calcium-hardened bony skeletons.
What are some adaptations of the bony fishes?
A protective flap that pushes water over the gills and a swim bladder to maintain buoyancy.
What animal groups have bony skeletons hardened with calcium?
Bony fishes, mammals, amphibians, and reptiles.
The majority of fish today are made up of what group?
Bony fishes
The fifth major development in the chordates’ phylogenetic tree is the development of _________
tetrapods
What animal group were the first tetrapods to evolve?
Amphibians
Characteristics of amphibians
Must lay eggs in the water, young have gills; adults usually have lungs and legs to move on land, moist skin
examples of modern amphibians
frogs, toads, and salamanders
The sixth major evolution of the chordate phylogenetic tree is the evolution of the_______ ___.
amniotic egg
What essentially is the environment of an amniotic egg?
An aquatic one that allowed creatures (reptiles) to reproduce away from the water.
Who were the first animals to develop the amniotic egg?
Reptiles
Main features of reptiles
scaly, waterproof skin and the amniotic egg
examples of modern reptiles
snakes, turtles, lizards, alligators, and birds
100 million years ago, what group of animals dominated the land?
Reptiles
100 mill. years ago, every land animal larger than a dog was a ______.
reptile