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
The final evolution of the chordates’ phylogenetic tree is the evolution of _______.
mammals
What are two key features of mammals?
Mammary glands that produce milk to feed young and hair that provides insulation.
What group of animals dominates the modern terrestrial landscape?
Mammals.
Which lineage was the first to develop jaws?
The fish lineage.
Modern fishes include what major lineages?
The hagfishes, the lampreys, the cartilaginous fishes, and the bony fishes.
Are most cartilaginous fishes predators?
Yes
Examples of bony fishes
Barracuda, goldfish, flying gurnard, thorny seahorse, yellow-ribbon sweetlips
T or F. All terrestrial vertebrates are tetrapods.
True.
amnion
the innermost membrane that encloses the embryo of a mammal, bird, or reptile.
ectotherms
an animal that is dependent on external sources of body heat.
what animals are ectotherms?
most non-bird reptiles
endotherm
an animal that is dependent on or capable of the internal generation of heat; a warm-blooded animal.
are birds endotherms?
Yes
What adaptations make birds good for flight?
- feathers, which aid in flight and provide insulation and waterproofing
- strong, light honeycombed bones and powerful breast muscles
modern mammals can be divided into what three groups?
monotremes, marsupials, and eutherians
monotremes
the last of the mammals that lay eggs
What species of monotremes are the only ones to exist today?
The duckbilled platypus and four species of echidna.
marsupial
a mammal that gives birth to a tiny embryonic offspring that completes its development in its mother’s
pouch, attached to a nipple, after a brief pregnancy
Why are most marsupials found in Australia?
60 mya, Australia split off from other continents. The isolation from the evolution of later mammal groups allowed marsupials to diversify intensely.
characteristics of eutherians
offspring are born fully developed after maturing with a placenta, which connects the fetus to the uterine wall. This system allows nutrient uptake, waste elimination, and gas exchange via the
mother’s blood
supply.
Many mammals are born encased in what?
An amniotic sac.
Examples of eutherians.
dogs, bats, cetaceans (aquatic mammals)
Within mammals, humans belong to what group?
Primates
Characteristics of primates
large brains, binocular vision, limber joints, limbs, and digits, complex behaviors, extended parental care.
Primates can be divided into two groups, _________ & _________.
nonanthropoid and anthropoid
Examples of nonanthropoids
tarsiers, lemurs, lorises, pottos
Examples of anthropoids
apes, old world monkeys, new world monkeys
The human evolutionary branch, the hominins, split off how many years ago?
5 to 7 mya
How many species of hominin fossils have been discovered?
Around 20
Out of the 20 hominin species, how many have survived?
1, ours.
What was the name of the oldest known hominin to evolve?
Sahelanthropus tchadensis
Which hominin was the second to evolve and the earliest to display bipedalism, a key human trait?
Australopithecus afarensis
“Lucy” was an Australopithecus afarensis (T or F)
Tru
When did Australopithecus afarensis evolve?
3.9 to 2.9 mya
The oldest known member of our own genus was a species known as _______.
Homo habilis
When did homo habilis evolve?
2.4 to 1.7 mya
What was significant about Homo erectus?
It was the first hominin species known to have migrated out of Africa to other continents
when did homo erectus evolve?
1.8 to 1.3 mya
when did Homo neanderthalensis evolve?
350,000 to 30,000 years ago
True or False: Homo sapiens and Neanderthals were direct relatives.
False, but they most likely interbred.
How long ago did homo sapiens evolve?
200,000 yrs ago
Describe homo sapiens’ path of migration away from Africa.
From Africa, our species spread into Asia (approximately 50,000 years ago), and then to Europe and Australia.
If the history of the world were a 24 hour day, how long before midnight would the genus Homo arrive?
34 seconds before midnight
Homo sapiens would arrive how long before the stroke of midnight if the world’s history were the length of a full day?
Less than four seconds before the stroke of midnight.
biodiversity
the variety of living things found on earth
the similarities between domain bacteria and arcahea
both are small, single-celled organisms with no nuclei
characteristics of archaea
prokaryotic, small, simple, inhabit extremes like salty or hot environments
where are bacteria found?
everywhere that life is found
characteristics of domain Eukarya
organisms are eukaryotic, which means larger, more complex cells that have a nucleus and other membrane-bound organelles
What are the three (mostly agreed upon) known kingdoms of Eukarya?
Plantae, Fungi, Animalia, and Protist
What does the protist category consist of?
Organisms that don’t seem to fit under plant, animal, or fungi.
Most protists are single-celled. (T or F)
True
Examples of protists
amoebas, paramecium, seaweed
True or False, seaweed is a protist.
True
if animals are consumers, and plants are producers, fungi are _________.
decomposers
Why are fungi important?
Their means of decomposing to get energy recycles chemical nutrients in an ecosystem.
examples of fungi
mushrooms, truffles (a kind of mushroom) yeast, and molds
plants
photosynthetic organisms that make sugar using the sun’s energy
the first major plant group to evolve
the byrophytes
byrophyte examples
mosses
byrophyte characteristics
lack vascular tissue, so aren’t very tall, and require water for sperm to circulate, so grow in moist environments
second major plant group to evolve
ferns
fern characteristics
seedless, but vascular, could grow taller than mosses. Sperm requires water, so growth happened in moist areas
gymnosperms
conifers, cone-bearing plants, not fruit-bearing
angiosperms
flowering plants
