Final Flashcards
Fungi are _______(cells never have more than one flagellum)
More specifically, they are ________(the single flagellum is always located at the posterior end of the cell)
Unikonts
Opisthokonts
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The common ancestor of the opisthokonts was likely _______ and _______.
unicellular and flagellated
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Evolutionist believe the common ancestor of opisthokonts was unicellular, which suggests __________ evolved in fungi and animals independently.
multicellularity
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Evolutionists believe fungi arose around ______ mya.
460
For nutrition, all fungi are __________.
absorptive heterotrophs
-more specifically, absoptive chemotrophs
Define absorptive heterotroph
A feeding strategy where an organism absorbs small organic compounds from enviroment and uses them for both energy and carbon source.
Many fungi secrete ________ into the environment to break down large organic molecules into small molecules that they can absorb.
enzymes
What 3 types of fungi exist and what do each absorb?
- Decomposers - break down dead organic matter (e.g. animal flesh, fruit, plant cellulose or lignin…) and absorb the products
- Parasits/pathogens - absorb small organic molecules from living cells
- Mutualists - absorb small organic molecules from living host, BUT also do something positive for the host
Fungal cells have cell walls that include the molecule _______.
chitin - a fibrous polysaccharide
What are the 2 major body forms of fungi?
- Unicellular fungi (yeasts) - unicellularity seems to have evolved several times in fungi (the common ancestor of the fungi was multicellular)
- Multicellular fungi - made of many tubular filaments called hyphae, which form a mass called mycelium
The common ancestor of the fungi was _____cellular.
multi
Hyphae forms a mass called _______.
mycelium
What are the two different forms of hyphae?
- Some hyphae are septate – the cells are separated by incomplete cross-walls called septae. Pores in the septae are pretty large, and sometimes allow nuclei to move from cell to cell.
- Some hyphae have no septae – these are known as coenocytic fungi. They basically consist of one large cell with many nuclei.
Septate hyphae contain ______, or cross wall that separate nuclei.
septae
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Coenocytic are one large cell with many _______.
nuclei
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The production of haploid ________ is important to most fungi.
nuclei
Unicellular fungi may reproduce asexually via ______ (simple
“fission”, or sometimes “budding”)
mitosis
Multicellular fungi may reproduce asexually by simply ________ into several parts; each part continues growing.
breaking
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Sexual reproduction in fungi starts with __________, when two haploid fungi fuse.
karyogamy
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Decomposers play an important role in the environment by:
- Getting rid of dead organisms
- Helps form the soil
- Recycles minerals and other nutrients (e.g. fungi respire CO2 into atmosphere)
Some hyphae produce __________, projections that press into plant cells without breaking through the plasma membranes
haustoria
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What are mycorhizae fungi?
Fungi that interact with plant roots; fungal hyphae form huge surface area of rootlike structure that provides water and minerals to plant, and plant provides photosynthate.
What are the two types oif mycorhizae?
- Ectomycorhizae - fungal hyphae wrap around the plant roots but do not penetrate plant cells
- Arbuscular - fungal hyphae penetrate into the root and enter the cell walls
Mycorhizae are essential for almost all _______ plants.
vascular
_________ fungi live in the above-ground parts of plants.
Endophytic
- these may be commensals or mutualists; exact relationship to host plant often not known
Lichens are stable symbioses formed by a ________ + a __________.
a fungus + a photosynthetic organism (a cyanobacterium or green alga, or both)
What are good indicators for air pollution since they can’t get rid of heavy metals and other toxins they absorb?
Lichens
Lichens can reproduce asexually by ___________, or by producing __________- a few photosynthetic cells bound by fungal hyphae
fragmentation
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soredia
What are some characteristis of chytrids?
- ALL aquatic
- can be unicellular/multicellular
- decomposers, parasites, and mutalists
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What are some characterists of zygomycetes?
- ALL terrestrail (moist places)
- some decomposers, parasits or commensals
- hyphae are coenocytic
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When there is lots of food, zygomycetes reproduce _________.
asexually
-hyphae form sporangia and make spores by mitosis
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When food is scarce, zytomycetes reproduce _______.
sexually
Describe sexual reproduction in zygomycetes
- Hyphae of two mating types grow towards each other
- Form gametangia which fuse to make zygosporangium (n+n)
- Haploid gamete nuclei in the zygosporangium fuse (karyogamy)
- Haploid sexual spores are released
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80% of all known plant species form mutualistic symbioses with __________.
glomeromycetes
Almost all _________ are mutualistic symbionts of plants, forming arbuscular mycorhizae
glomeromycetes
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What two synapomorphies link ascomycetes and basidiomycetes?
- ALL have septate hyphae
- They have a dikaryon stage
What is a dikaryon stage?
A stage after plasmogamy and before karyogamy, where two (and only two) genetically different haploid nuclei coexist in each hyphal cell
_________are also known as “sac fungi”, since they form small sacs (asci; singular ascus) in which meiosis occurs to produce ascospores.
Ascomycetes
For ascomycetes, asexual reproduction happens by the formation of ________
conidia (haploid spores)
What gives some mold their color?
conidia
For ascomycetes, sexual reproduction happens when ____________ which results in _______________.
haploid hyphae fuse (plasmogamy)
8 haploid ascospores
What are ascocarps?
The fruiting bodies of some multicellular ascomycetes
Penicillin is produced from what ascomycetes fungus?
The green mold Penicillium
Yeasts (unicellular fungus) reproduce asexually by ________.
budding
For ascomycetes, describe sexual reproduction
- Cells of different mating types fuse
- Zygote nucleus undergoes meiosis to form ascospores
- The whole cell is the ascus
What type of fungi do we typically think of as mushrooms?
basidiomycetes
Describe reproduction in basidiomycetes
ONLY reproduce sexually
- Haploid hyphae fuse (plasmogamy)
- Dikaryotic hyphae form a fruiting body (basidiocarp), which bears many basidia
- Karyogamy occurs, making a single diploid nucleus in each basidium; this undergoes meiosis, making 4 haploid cells, each of which becomes a basidiospore
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In contrast to plants and fungi, animals cells lack a __________.
Cell wall
Animals are heterotrophsby _______, fungi are heterotrophs by __________.
ingestion
absorption
What is the significance of a short-lived diploid state in fungi?
Generate genetic variation
Which are two possible relationships between plants and fungi?
- Plants depend on fungi as mutualistic symbionts
- Plants are harmed by fungal pathogens
Gastrulation is the process that directly forms the ________
primary germ layers
The earliest ancestors of about 50% of all extant animal phyla can be traced back to the _____ explosion.
Cambrian
____________ are sister-taxon to the animals.
choanoflagellates
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What is the key difference between a coelom and a pseudocoelom?
- Coelom is completely lined with mesoderm tissueand
- Pseudocoelom IS NOT completely lined by mesoderm layer
Which feature of deuterostome development explains the formation of identical human twins?
Deuterostomes have indeterminate development
Cnidarians have a _____________, which is the digestive compartment of cnidarians.
Gastrovascular cavity
The animal phylum most like the protists that gave rise to the animal kingdom is ___________.
Porifera (sponges)
Choanoflagellates are _________ feeders
suspension
Describe the morphology of choanoflagellates.
Cells with one flagellum, surrounded by a ring of microvilli
Multicellularity evolved in _______ and ________.
Fungi and animals
How did multicellularity arise in the common ancestor of the animals?
The evoloution of:
Cell adhesion proteins- proteins that allowed cells to stick together
Cell junctions
Cell signalling pathways- cell communication
What are cadherins?
Cell adhesion proteins found in ALL animals.
Animals are a ____________ taxon
monophyletic
What do animals cells have to choanoflagellates do not which allows for cell ahesion (multicellularity)?
Cytoplasmic cadherin domain (CCD)
What synapomorphies of the animals differentiate them from choanoflagellates and other eukaryotes?
- Unique cell junctions
- Extracellular matrix molecules (collagen)
- Cell ahesion molecules (CCD-cadherin)
- Cell signaling pathways
What are some features of animals?
- ALL multicellular
- All chemohetertrophs
- All digest food internally
- Specialized cells for electical signals (nerve) and contract (muscle)
- Have Hox genes - control patterning of embryo
How can we categorize animal diversity?
- Body symmetry - radial or bilateral
- Cleavage patterns - radial or spiral
- Number of embryonic tissue layers
- Fate of blastopore
- Body cavities
Bilateral symmetry is associated with _____________, a brain.
cephilization
Radially symmetrical animals tend to be _________.
sessile
If only two embryonic tissue layers (ectoderm and endoderm) are formed, the animal is called a _____________.
If a 3rd layer (the mesoderm) is formed between the other two, the animal is called a ______________.
diploblast
triploblast
Compare radial cleavage and spiral cleavage
Radial - all divisions are parallel/perpendicualr to AV axis
Spiral - Starting from 3rd division, all divisions are slightly off-parallel/perpendicular from AV axis
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Radial cleavage is associated with _______________ development.
Indeterminate
Each cell in 2 and 4 cell stage can develop into complete organism (twins)
Spiral cleavage is associated with ____________ development.
determinate
Each cell in 2 and 4 cell stage is determined for specific function
The zygote undergoes cleavage to form the _________.
blastula
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The hollow space inside the blastula is called the ____________.
blastocoel
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When cells from the outside of the blastula move into the blastocoel, this is called ____________.
gastrulation
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The endoderm surrounds a space called the __________, and connects
to the outside via the __________.
archenteron
blastopore
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In __________, the blastopore becomes the mouth.
Protostomes (mouth first)
In __________, the blastopore becomes the anus.
deuterostomes (mouth second)
What are the 3 types of body cavities in animals (in addition to the gut)?
acoelomate: no fluid-filled cavity - Full of mesoderm
pseudocoelomate: there is a fluid-filled cavity between gut and ectoderm… but it is not completely lined by mesodermal tissue
coelomate: there is a fluid-filled cavity between gut and ectoderm… and it is completely lined by mesodermal tissue called peritoneum
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Protostome development is correlated with ________ cleavage.
Spiral (determinate)
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Deuterostome development is correlated with __________ cleavage.
Radial (indeterminate)
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For protostomes, the coelom is formed by the splitting of the ______________.
mesoderm
For deuterostomes, the coelom is formed from folds of ______________.
archenteron
Compare direct and indirect development
Direct development:
zygote → embryo → juvenile → adult
Indirect development:
zygote → embryo → larva → juvenile → adult
What is a larva stage?
Stage where organism looks very different than juvenile/adult stage and undergoes metamorphosis
For animals that are sessile as adults, dispersal usually takes place in the ________ stage.
larval
Vertebrates are a subgroup of the phylum __________.
Chordata
Animals in the clade Bilateria are __________ symmetirical ______blasts.
bilaterally
triploblasts
What are 5 features of sponges?
- Asymmetric (neither radial nor bilateral)
- no true tissue layers (so neither diplo nor triploblastic)
- no digestive system
- no nerves
- no muscles
Compare unitary and colonial animals
Unitary - one individual (humans, birds)
Colonial - adult is composed of many “individual animals” that function together
What are the 3 cell layers for Porifera (sponges)?
- Outer layer - epidermis (pores)
- Middle layer - mesohyl (spicules + spongin)
- Inner layer - choanocytes (look like choanoflagellates)
Porifera are __________ feeders.
suspension
The cnidarians and ctenophores are ____blastic.
diploblastic
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What are 4 features of Cnidaria (jellyfish)?
- Radially symmetrical diploblasts
- Have a gut (NO anus)
- Have contractile cells
- Have nerves
Cnidaria come in two body types: _______ and ________.
polyp and medusa
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In Cnidaria, the ectoderm forms the _________ and the endoderm forms the __________.
epidermis
gastrodermis
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Cnidaria catches prey using ________, the most common of which is __________.
cnidae
nematocyst
In species with both polyp and medusae, the polyp reproduces _________, and the medusa _________.
asexually
sexually
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Cnidarians usually have a _______ larval stage
planula
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The two major clades of cnidarians are:
- Medusozoans - have medusa and polyp in life cycle
- Anthozoans - only a polyp in life cycle
A type of Anthozoan is a _________
coral
___________ have mutualistic symbiosis with dinoflagellates
Corals
In corals, warming and stress can lead to the expulsion of _____________ (coral bleaching)
dinoflagellates
Ctenophora are _________ symmetrical diploblasts.
radially
Ctenophora swim using _________, which are arranged in 8 rows (comb rows)
Ctenes
Bilaterians are ___________ symmetrical triploblasts and have a _________ gut.
bilaterally
complete
Why do triploblasts have to increase their Surface Area to Volume ratio?
They have a middle tissue layer (mesoderm) which needs to perform gas exchange.
What are the 3 clades of Bilaterians?
- Deuterostomia
- Lophotrochozoa
- Ecdysozoa
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The diagnostic feature of Chondrichthyes is _____.
an endoskeleton of calcified cartilage
The Lophotrochozoa + Ecdysozoa is often called the __________.
Protostomes
As hominins have evolved, sexual dimorphism has significantly __________.
reduced
What are the 3 main groups of mammals?
- Monotremes - egg-laying
- Marsupials - pouch
- Eutherians - Placenta
Members of the Lophotrochozoa clade have either ________________ or _______________.
a lophophore or a trochophore larva
(but some have neither)
What is trochophore larva?
Tiny planktonic larval stage that has a band of cilia
What is a lophophore?
Ring of ciliated hollow tentacles used for feeding/gas exchange.
What are key features of Platyhelminthes (flatworms)?
- Unitary and acoelomate
- Incomplete guts
- No organs for gas exchange so High SA/vol ratio
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What are some key features of planarians (most common flatworm)?
- A brain and sensory structures
- Regeneration
What are the two parasitic flatworms?
- Trematodes - internal parasite of vertebrates
- Tapeworms - internal parasite of vertebrates
A type of trematode (parasitic flatworm) is ____________, which causes schistosomiasis (liver damage).
Schistosoma
2 larval stages, the second of which infects mammals
Tapeworms hold on to host with a _______ and most of their body chain is _________.
scolex
proglottids (egg, sperm)
Syndermata are also know as _________.
Rotifers
What are some key features of rotifers?
- Unitary and pseudocoelomate
- Have corona (crown of cilia)
- Have mastax to chew up food
- Can lose 99.5% body water and become cryptobiotic (inactive dormat state)
Most rotifers undergo _______________.
cyclical parthenogenesis (diploid eggs that develop without fertilization)
What is cyclical parthenogensis?
Asexual reproduction when conditions are good - females make diploid eggs that can develop without fertilization
Under bad conditions, they reproduce sexually to produce zygote
Bdelloid rotifers are all _______ due to parthenogensis.
females
What are some key features of Ectoprocts?
- Colonial and coelomate
- Use a lophophore for suspension feeding/gas exchange
- Larvae undergoes metamorphoses and forms first member of colony which undergoes asexual reproduction
What are some key features of Brachiopods?
- Unitary and coelomate
- Use lophophore for suspension feeding/gas exchange
- Common in Paleozoic
What are some key features of molluscs?
- Unitary and coelomate
- 3 body regions (foot, visceral mass, mantle)
- mantle cavity (space lined by mantle)
- radula (teeth)
What are the 3 body regions of molluscs?
- Foot - movement
- Visceral mass - internal organs including complete gut
- Mantle - secretes shell
Radula (teeth) in molluscs can be used for _______ or ________.
scraping
stabbing - secretes conotoxins
Disulfide bridges are made from ________
cysteine
Conotoxins are __________ of 10-30 amino acids that have at least one _______ bridge. They work to paralyze prey.
polypeptides
disulfide
The conotoxin _________ binds to ion channels involved in sensitivity to pain. A synthetic form was made that is 1000 stronger than morphine.
ziconotide
Most molluscs have a life cycle that includes a ____________ larval stage.
trochophore
What are the 4 major groups of molluscs?
- Chitons - omnivores, strong radula
- Gastropods (snails) - one shell (snails) or no shell (slugs)
- Bivalves - two shells with hinge in between
- Cephalopods (squids, octopus) - Jet propulsion by shooting water out of a siphon
What are some features of annelids?
- unitary and coelomate
- complete guts
- trochophore larvae
- segmented
Each segment of annelids has its own _____________ and ____________.
coelomic cavity and brain
2 large clades of annelids are:
- Errantians - move around via parapodium made of chaetae
- Sedentarians - earthworms and leeches
Parapodia is used for ___________ and helps increase __________.
movement
SA-V ratio
What is a clitellum?
Reproductive structure in earthworms and leeches.
The Ecdysozoa are sister taxa to the __________. Together, they are called the ____________.
Lophotrochozoa
protostomes
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What phyla contains over 1,000,000 described species (~75% of ALL described animal species)?
Arthropods
The bodies of all ecdysozoans are covered with an extracellular layer called the __________.
cuticle
What are some key features of nematodes (roundworms)?
- unitary and pseudocoelomate
- Live virtually anywhere
- Complete gut
What is a nematode species that is an extremely important model system in developmental biology? What fixed number of somatic cells do adults of this species have?
Caenorhabditis elegans
959 somatic cells
What phylum has millions of undescribed parasite species?
Nematodes (round worms)
What nematode animal parasite is used to treat Crohn’s disease and colitis?
Trichurus suis (whipworm)
Arthropods have a pair of _________ _________ on each segment.
jointed appendages
What are 3 different tasks an arthropod can use its joined appendages for?
- Walking/swimming
- Feeding
- Gas exchange
Early arthropods had segments that were ________ to one another. Modern arthropods have segments that are ___________.
similar
different (specialized for various tasks)
Arthropods have an _______ circulatory system in which the blood is not always in a vessel.
open
What are the 3 main clades of arthropods?
- chelicerates
- myriapods
- pancrustaceans
What are the 2 body regions of chelicerates and how many pairs of walking legs do they have?
cephalothorax and abdomen
4 pairs
What are 2 types of appendages used for feeding by chelicerates?
chelicerae - grab food, inject poison
pedipalps - sense food, grab food
What are 3 phyla of chelicerates?
- Pycnogonids (sea spiders) - male paternal care
- Horseshoe crabs - “living fossils”
- Arachnids
What are the 2 body regions of myriapods (ceni/millipedes)?
Head (with pair of antennae) and long trunk
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The pancrustacean clade includes:
crustaceans + insects
What 3 body regions do crustaceans have?
Head, thorax, and abdomen
Crustaceans have a ________ larval stage
nauplius (not much different from juvenile/adult)
Insects have a unique gas exchange system in which spiracles on the thorax open into long, narrow tubes called ________.
trachea
For insects, the thorax has _______ pairs of walking legs and the abdomen has no ________ _________.
3
jointed appendages
Most insects have 2 pairs of wings which are large extensions of _________ on the thorax.
cuticle
How did insect flight affect diversification?
A burst of diversification of both insects and angiosperms.
Compare complete vs incomplete metamorphosis.
Complete - larva looks very different from juvenile/adult
Incomplete - at every molt, larval stages look like small adults
Deuterostomes are sister taxon to the __________.
protostomes (lophotrochozoa + ecdysozoa)
All deuterostomes are __________.
coelomate
What are the 3 body parts of a hemichordate? What do they use their pharyngeal slits for?
Proboscis, collar, and trunk
Gas-exchange surface for respiration
Echinoderm (sea star) larvae have ________ symmetry but adults have ________ symmetry.
bilateral
pentaradial
Echinoderms have water vascular system that they use for:
- locomotion
- feeding
- gas exchange (respiration)
5 phyla of echinoderms are:
- Crinoids - oldest, suspension feeders
- Sea stars - motile predators
- Brittle stars - motile
- Sea urchins - motile, large spikes
- Sea cucumbers - motile, suspension-feeders
Chordates are all _________ symmetrical, coelomate, and _____________
bilaterally
segmented
What are 4 key traits that define chordates?
- Notochord
- Dorsal, hollow nerve cord
- pharyngeal slits
- muscular, post-anal tail
What are the 3 things that can happen to the notochord?
- Cephalochordates have it their whole lives
- Urochordates lose it at metamorphosis
- For Vertebrates, it becomes part of the vertebral column
What are the two “invertebrate” groups within the chordates?
Cephalochordates and Urochordates
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Cephalochordate (lancelets) are known as ______ chordates.
Urochordates (tail chordates) only have those key chordate traits in the _______ stage.
larval
Urochordates secrete an exoskeleton of cellulose (a “tunic”) are are often called __________
tunicates
What are the 3 groups of urochordates?
- Ascidians (sea squirts)
- Thaliaceans (giant condoms)
- Larvaceans - never metamorphosis
What is the correct order of events in fungal sexual reproduction?
plasmogamy, karyogamy, meiosis, germination
Hyphae with two nuclei per cell are called _____.
dikaryotic
During the development of most animals, cleavage leads to a _________ __________.
multicellular blastula
Name the embryonic stages in the order that they develop?
zygote, blastula, gastrula, larva
All animals with bilateral symmetry have __________ germ layer(s).
3
All animals with radial symmetry have __________ germ layer(s).
2
The zygotes of many protostomes undergo __________ cleavage and __________ cleavage.
spiral…determinate
An animal with a true coelom that has __________ cleavage must be a(n) __________.
radial….deuterostome
Some species of rotifers undergo parthenogenesis, which means that __________.
females ONLY that produce more females
Molting is also called ________.
ectysis
What are some key characteristics of vertebrates?
- A jointed dorsal vertebral column surrounds dorsal nerve chord
- Hox genes
- A skull
Vertebrates have at least _______ copies of Hox genes.
2
*Usually have more
What are the 2 cyclostomes (jawless fishes)?
- Hagfish - cartilagenous skeleton/skull, secrete slime for defense
- Lamprey - cartilagenous skeleton/skull, larvae called ammocoetes
*Both have tooth-like structure made of keratin
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What are the key features of gnathostomes?
- jaws
- mineralized skeleton
- Paired pectoral/pelvic fins
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Jaws evolved from skeletal ______ that supported the _______around the slits.
arches
pharynx
What are the 3 clades of Gnathostomes?
- Chondrichthyans (sharks, rays)
- Actinopterygiians (ray-finned fishes)
- Lobe-fins
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Chondrichthyans are known as __________ fishes since their skeltons contain no bone.
cartilagenous
For actinopterygians, outgrowths of the gut evolved into __________ _________ in ray finned fishes and __________ in other bony vertebrates.
swim bladders
lungs
For actinoptergians, ________ covers the gills.
operculum
A type of lobe-fin called __________ (Actinistia) was thought to be extinct but living specimens were found in 1938.
coelocanths
___________ (Dipnoi) have lungs and gills but only use the ________ for breathing.
Lungfishes
lungs
In what group of animals did new bones in the pectoral/pelvic fins first appear that allowed it to support itself in shallow water?
Lobe-fins
The bones in the pectoral/pelvic fins eventually become more complex and formed limbs with ________ used for walking/running.
digits
What are some traits of tetrapods?
- a neck
- a pelvic girdle
- pharyneal slits used for functions OTHER than respiration
_____________ is a recently-discovered fossil that share traits of both lob-finned fishes and tetrapods.
Tiktaalik
What are the two life phases of amphibians?
aquatic larva - lacks limbs, post-anal tail, gills
adult - has limbs, lungs, no tail
Why are amphibians confined to moist habitats?
- Aquatic larvae
- Eggs DO NOT have a shell
- Most adults use both lungs and diffusion
What are the 3 clades of amphibians?
- Salamanders
- Anurans (frogs/toads)
- Caecilians (wormlike, lost limbs)
Amniotes have an _________ egg and include which two phlya?
amniotic - embryo surrounded by 4 membranes and shell
reptillia and mammals
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What are the 4 membranes that amniotic eggs have?
- Amnion - protects embryo
- Allantois - gas exchange, waste
- Yolk sac - nutrients
- Chorion - gas exchange
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Amniotes can be fully terrestrial because the amniotic egg develops in an ___________ environment.
aqueous
What are 2 key features of amniotes?
- Amniotic egg
- Negative pressure lung ventilation
Reptiles have an outer layer of skin that forms _________ and contain the protein __________.
scales
keratin
What are 3 key features of reptiles?
- Scales (kertain)
- Internal fertilization (oviparity or ovoviviparity)
- Exothermic
Compare oviparity and ovoviviparity.
oviparity - deposit amniotic egg on land
ovoviviparity - egg develops in mother, gives birth to juveniles
What are the 3 clades of living reptiles?
- Turtles
- Archosaurs
- Lepidosaurs (overlapping scales)
What are the 2 groups of lepidosaurs (overlapping scales)?
- Tuataras - New Zealand ONLY
- Squamates (lizards, snakes, amphisbaenians)
What are the 2 groups of Archosaurs?
- Crocodilians
- Birds (therapods)
What are 5 key features of therapods (birds)?
- Bipedal
- Furcula
- Hollow bones
- Three fingered limbs
- Feathers (insulation)
What are the 2 main groups of birds?
Paleognaths - flighless birds
Neognaths
200 mya one lineage of ________ split off to form a clade called mammals.
synapsids
What are 5 key features of animals?
- Sweat Glands
- Mammary glands
- Hair
- Differentiated teeth
- Bones in middle ear
Which of the following chordate characteristics contributes most to the formation of mammal’s ears?
pharyngeal slits/clefts
A __________ is a chordate but not a vertebrate.
lancelet (cephalochordate)
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Which of the following chordate characteristics contributes most to suspension-feeding devices in many invertebrate chordates?
pharyngeal slits/clefts
___________ are jawless invertebrae chordates and __________ are jawless vertebrae chordates.
Lancelet
Lamprey
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What is the correct order of probable ancestors of modern humans from the earliest to the most recent?
Sahelanthropus, Ardipithecus, Australopithecus, Paranthropus, Homo
What is a common species and traits of monotremes?
platypus
- lay eggs
- no placenta
- mammary glands but NO nipples
- sprawling orientation
What are some key traits of primates?
- limbs with grasping hands and feet (except humans don’t have a thumb on their feet)
- flat face, eyes forward
Anthropoids include what two monkey groups?
Old Wolrd - NO prehinsile tail, ground-dwelling
New World - prehensile tails and arboreal (tree dwelling)
What was one key trait that evolved in the common ancestor of hominins?
bipedal locomotion
Members of the ______ genus have larger brains and less elongated faces than their hominin relatives.
Homo
The earliest species of the genus Homo is _______.
habilis
“Ardi” is in the genus ________.
“Lucy” is in the genus Homo _______.
Sahelanthropus
Australopithecus
For the genus Homo, as brain size _________, jaw size ________.
increases, decreased
Homo sapiens evolved in ________.
Africa