Tina bio, Bio 221 final
Terms in this set (90)
Define: Ecological Footprint
the aggregate land and water required by a person, city, or nation to produce all the resources it consumes and to absorb all the wastes it generates
The impact of a person or community on the environment, expressed as the amount of land required to sustain their use of natural resources.
How large is the human population currently? Predicted size in the year 2050?
Currently: 7.2 billion
2050: 9 billion
-Invasive species and diseases
A) Australia, marsupials, red foxes
A) Coral reefs, water is too warm, dinoflagellates are expelled and corals are bleached, oceans are becoming more acidic
A) Sharks, over fishing, rhinos and elephants, pangolins
A) we are becoming more disposable
B) it was worse become eco laws were passed in the 1960's
What are current and projected levels of species extinction?
-Current extinction rate is up to 1000x higher than the fossil record
-Projected is more than 10x higher than current rate
Why is species "Value" best considered unpredictable
-B/c technology changes our ability to derive value
-The potential of a species is spread across a spectrum of unknown an as yet unimagined human needs
-The diversity of life sustains this planet and humanity and has immense/unpredictable value to humanity
Give two examples of potentially valuable biomolecules derived from animals
Prialt--> alternative to morphine
Silk from spiders
What are ecosystem services
Provide two examples
-waste removal via nutrient cycling (deritivores)
-control of "pest" population
-purification and retention of freshwater
What proportion of species on Earth remain undiscovered and unsubscribed?
-3/4 we have documented 1/4 of every species on this planet
What are the 3 hierarchical levels of biodiversity
a) molecules, genes
a)species in a coastal redwood forest
-community and ecosystem
a)diversity across the landscape of an entire region
Are maternal and fetal circulatory systems fused in a human placenta? explain...
-They are in close contact but not fused.
-separate immune systems important for maximizes nutrient exchange but not triggering immune response
What are the four primary functions of the Eutherian Chorioallantoic placenta?
-physically anchors fetus to uterus
-transports nutrients/oxygen from
-removes metabolic wastes from fetus (co2 N wastes)
-produces hormones that help regulate pregnancy
What is the Eutherian Trophoblast, and what role does the trophoblast play in preventing immunorejection?
-Provides a barrier that separates embryonic tissue from maternal immune system, but still allows for materials to pass
a)Shielded from maternal immune system
-B/c of this later, the embryo can "hide" from maternal immune system from the start of implantation which allows for a longer gestation period
-Effiecent way to be separated and leads to a longer gestation
-B/c of this longer gestation period eutherian young are more developed in comparison to marsupials
Describe how the marsupial thin shell membrane relates to maternal immunorejection, and short gestation periods observed in marsupials.
-In oviduct, mucoid protein coat forms around fertilized egg. In uterus a coat of keratin fibers forms thin shell membrane
-to combat this.... there is a shell membrane that acts as a barriers to prevent immunorejection
Distinguish between estrus, monestrous, and polyestrous. Estrus is a physiological state within the female body- how do females "advertise" this physiological state to potential males?
-Estrus--> "Heat" coincident w/ovulation. Multipart cycline involving changes to developing follicles/ova. copulation restricted to specific periods of estrous cycle
a) on chance a year to reproduce
b)very important to advertise females show that they are fertile through visual cues, acoustic cues, behavioral cues
-Primates with menstrual cycle are receptive throughout the cycle
-Polyestrous---> more that one estrus cycle per year
Be able to describe the events that lead to the production of ovum from a primary oocyte (e.g following Fig 46.11b of text). Define ovulation.
-Ogenesis discontinuous, starts in fetal ovary
-Before birth, primordial germ cells are ALL primary oocytes via mitosis, meiosis begins...
-Meiosis resumes at sexual maturation (puberty producing secondary oocytes to ovulation to fertilization required for meiotic division producing ovum
Define spermatogenesis, and the role of sertoli cells in this process.
-Spermatogenesis--> means producing sperm, continuous in mature males
-Haploid gamaes (sperm) produced in seminiferous tubules
a) sertoli cells nurture germ cells (potential gamete)
Be able to define and distinguish between oviparaous, ovoviviparous, and viviparous
-oviparous: Female lays fertilized eggs into environment for deleopment
-Ovoviviparous: retains egg and egg hatches w/in the boy of the parent, intermediate b/tw oviparious and vivparous
a) embryos deriving nourishment from egg yolk
-Viviparous: live birth; embryos deriving nourishment directly from mother
Known the difference between natural selection vs sexual selection
-sexual selection: a mode of natural selection where the members of one biological sex choose mates of the other sex to mate with and compete with member of the same sex for access to member of the opposite sex
-Natural selection: the process whereby organisms better adapted to their environment ten to survive and produce more offspring.
what three groups are dueterosomes
echinoderms, hemichordates, and vertebrates
in what traits do they differ from protostomes
duplication of posterior HOX genes, dorsal nervous system and the blastopore forms the anus
what organisms are echinoderms
astroidea, echinodea, holothuridea, crinodiea, ophiuroidea
recall the four key chordate characters. these characters evolve into different structures with different functions in derived chordates - give an example using the pharyngeal gill sets
1. dorsal, hollow nerve cord
2. notochord (fibrous, supportive rod that extends the length of the body beneath dorsal nerve cord)
3. pharyngeal slits/clefts (suspension-feeding devices, allow water to bypass digestive tract)**respiration
4. muscular, post anal tail
-pharyngeal slits are gills in aquatic vertebrates and jaws in jawed vertebrates
why are sea squirts (tunicates) strange chordates
the chordate characteristics are seen in the larval stage
what are key vertebrate features/innovations
bony tissues -> mineralized connective tissue = bony vertebrate
vertebrates have "dermal bone" that acts as exoskeleton
dorsal, ventral and anal (DAV) fins allows for more efficient locomotion
what are neural crest cells? what are important cells derivatives of neural crest cells? use example
-ectoderm in origin but practically the 4th germ layer cell
-they are migratory (move to dif places in body) and form impt structures
- adds to complexity and innovation seen in vertebrates
- ex from adult vertebrate -> peripheral nervous system, facial cartilage and bone, pigment cells
vertebrates are said to be morphologically disparate - what does this mean
-they have a great variation in morphological form despite relatively limited species diversity
- contrast with beetles (huge # of species, limited diversity in form)
what does the word gnathostome mean
jaw mouth; have DAV fins + paired pectoral and pelvic fins
jaws evolved from which structures in more early-diverging vertebrates? what is the evidence from this homology?
-jaws evolved from anterior pharyngeal arches of early-diverging vertebrates
-evidence = posterior pharyngeal arches retain gas exchange function in gnathostomes
- evidence for gill rod:
position on body (positional homology), both structures derived during development from neural crest cells, nerve dist to assoc muscles is similar
why are gnathostomes successful
-jaws and teeth -> grasp, manipulate, shear food objects = new food resources become available
-unpaired + paired fins -> paired pectoral and pelvic fins allow for better, faster, more maneuverable swimmers
genes are often duplicated in genomes (i.e., a single gene gives rises to two "daughter" genes through duplication of a chromosome or part of a chromosome). what are the three possible fates of such duplicated genes?
1. pseudohgene -> lose functionality, go "extinct"
2. neofunctionalization -> evolve a new function different from ancestral gene
3. subfunctionalization -> two daughter genes each take on park of function of mother gene. undergo division of labor by retaining diff parts (subfunctions) of their original ancestral function
---the two gene copies degenerate to perform complementary functions that jointly match that of the single ancestral gene
what is placoderm
-extinct pre-historic fish, "plate skin"
- heavily armored head regions with lots of dermal bone
- w jaws but lack teeth implies jaws first evolution in gnathostomes
what are some primary characters of Chondrichthyes? (Sharks, rays, skates)
-well developed paired fins and toothed jaws
- countercurrent gill respiration
- mostly cartilaginous endoskeleton
-large, oily livers aid in buoyancy
how are teeth in Chondrichthyes related to placoid scales? how do shark teeth differ from the teeth of other Gnathostomes?
-placoid scales are mineralized dermal tissues, they have the same structure as their teeth
-using same proteins, teeth are derived from skin**similar
- structure, developmental organ, and proteins
- chond teeth form from skin as whorls that rest on the jawbone while other gnath have teeth embedded into jawbones
-----different developmental origin
describe and define the function of the lateral line system, and of the ampullae of lorenzini
- lateral line system -> used for mechanoreception (detect low freq vibrations in water)
----detects displacement in water ex. if fish is moving in h2o
----extremely sensitive hair cells that respond to water displacement
- general system for mechanreception in aquatic gnathostomes
- ampullae of lorenzini -> sensitive electroreceptors, allows sharks to detect nearby objects by reflected waves in the water
----can perceive electrical fields generated by fish
why cant shark populations quickly rebound after over-harvesting --- at least three reasons
1. take a while to be sexually mature
2. litter size is small
3. reproductive freq is low
4. have a long gestation period
did gnathostome lungs evolve on land, or in aquatic habitats? what is the evolutionary fate of lungs in some Ray-finned fishes? how do these animals thus respire?
-lungs evolved in fishes
-initially evolved as evaginations of pharyngeal region of digestive tract
-swim bladder is evo fate of lungs in ray finned fish, thus they respire using counter-current respiration
-lung fish use lungs to get air
- lungs evolved before terrestrial organisms
-lung fish depend on lungs for o2 when needed but have gills
the ray-finned fish epidermis has multiple functions - what are these
-secrete mucus -> reduces drag, protection against pathogens
- nearly watertight -> barrier to water gain/loss
explain how the countercurrent exchange mechanism allows fish to extract oxygen from the water as it flows over their gills
- blood and water flow in opposite directions, which creates a situation where water always has higher oxygen concentration than the blood, THUS oxygen moves from the water into the blood
what are modern coelocanths considered "living fossils"? what are general characteristics of living fossils?
-living fossils: a living species that closely resembles species otherwise known only from the fossil record
- typically have slow rates of morphological evolution (living species surprising similar in morphology to fossil species )
-coelacanths have fossils in the same lineage range from 400-75 mya representing 125 dif species
-look very similar to fossils, more diverse fossil record (more species of coelocanths)
how do lungfish breathe? when during vertebrate evolution did lungs evolve (i.e., at the base of which clade, where on the vertebrate tree)?
-both gill and lung respiration
---lungs allow them to breathe air in water w/low o2 levels
---lung is a modified swim bladder
-lungs evolved w/in the clade Osteichthyans and Lobe-fins
---lungs evolved at the base after cartilaginous fish cut off, rayfinned fish and other tetrapods
what are the two primary groups of living tetrapods
2. amniotes ("reptiles", birds, mammals)
when did tetrapod terrestrial invasions occur? were tetrapods the first animals onto land?
-devonian invasions (360-380 mya)
-no, plants and other animals were already on land
tetrapods ultimately evolved to be land animals. what characters already possessed by tetrapod ancestors facilitated this transition to land?
1. bony endoskeleton -> system of body support in non-supportive environment
3. pectoral & pelvic girdles w/ associated limbs + terminal phalanges (land based locomotion)
why is Tiktaalik an important fossil tetrapod - i.e., what does this fossil tell us about tetrapod evolution
-tiktaalik had ulna, radius, and humerus
-bones of the front fin of tikaalik (fish w/a wrist)
what are some of the ecological reasons that tetrapods may have invaded land?
1. unexploited food resources on land (arthropods)
2. very little competition (np big animals)
3. lots of competition and many predators in water
amphibians are either "tied to water" (i.e., must have water to complete part of their lifecycle). or found in moist terrestrial habitats. what aspects of amphibian biology impose these constraints?
-thin permeable skin that lacks scales -> implies desiccation (Extreme dryness) in dry habitats
- allow for respiratory gases to pass through skin
- eggs are covered w/ jelly-like substance (no protective shell)
name 4 major anatomical changes that occur in the transition from tadpole to adult frog?
1. loss og gills
2. formation of limbs
3. loss of tail
4. change of digestive system
there are multiple causes for amphibian population crashes and species extinctions - what are these? one cause is particularly problematic - what is this problem? remember that we talked about it previously
1. habitat destruction
1. introduced species (e.g., mountain yellow-legged frogs impacted by introduced trout in CA)
2. climate change, including increased UV-B radiation
3. water pollutants
4. emerging infectious diseases -> chytrid fungus
describe the amniote egg, including functions of the four extraembryonic membranes. why does the amniote egg further facilitate life on land?
-amniote egg w protective shell -> permeable to respiratory gases but retains water in drier situations
--kertatinized cells resistant to abrasion and water loss
---1. amnion: surrounds embryo in fluid-filled cavity; cushioning and preventing dehydration
---2. allantois: extends from hind gut; storage of metabolic waste products, aids in gas exchange
---3. chorion: outer-most membrane; involved in gas exchange
---4. yolk sac: includes yolk; providing nutrients
what are key structural proteins in the amniote integument? give three ex of epidermal structures that are mostly comprised of these key proteins. how do these structures further facilitate life on land?
-outer most cell layers accumulate tough structural proteins (keratins)-> they replace all/most metabolically active cytoplasm
-they are resistant to abrasion and water loss -> facilitate life on land
- skin covering, mammal hair, hair derivatives (claws, hooves), scales, feathers
there are a large number of terrestrial, lungless salamanders. why are there no lungless lizards?
dont have permeable skin
about how many times has a snake-like form evolved from a limbed ancestor within living Lepidosaurs? what features can you use to determine a true snake from a legless lizard?
-about 25 times
-legless lizards have eyelids, external ear opening and can lose (and regrow) their tail
-snakes lack external ear openings, eyelids
what is the most successful clade of Lepidosaurs? what unique adaptations have helped them?
--jaw morphology allows them to eat large prey
-----enlarged rostral scale (Assists in digging)
-----toxin delivered via fangs
-----primary purpose is dietary, second is defense
be able to describe the mimicry seen with coral snakes
-coral snakes have a powerful neurotoxin, many snakes have evolved coloration/pattern that mimic coral snakes
-batesian mimicry -> harmless species evolve coloration/pattern/behavior that mimics the harmful species
what is the sixth sense that some snakes have evolved (such as pit vipers)
-evolved ability to detect heat
-pits on the face house receptors that detect infrared heat
how many times do we know viviparity evolved in mammals? contrast that with how many times it has evolved within living Lepidosaurs
-viviparity -> retetion/growth of the fertilized egg w/in the maternal body until the young animal is capable of indp existence
- viviparity evolved once in mammals, and over 110 times w/in snakes/lizards
what groups are in the clade Archosauria? what similarities do crocodilians share with their closest living relatives?
-birds, dinosaurs, and crocodilians
-crocodilians are sister to birds and dinos
---four chambered heart, vocalize or "sing", build and guard nests for their eggs
what kind of data have established the sister group to turtles? what clade are they sister to?
-genomic data est phylogenic relationship
-sister to archosaurs
what is a turtle shell made from? what are some anatomical modifications that evolution of a shell required?
-turtle shell is made from scutes (thickened horny or bony plate) made of dermal shell
-broadening of the ribs, encapsulation of the shoulder blade w/in the shell, fusion of the vertebrae & clavicle to shell
what incredible talent does the Filtroy River Turtle from Australia have
-water pumped in/out of cloaca, gas exchange occurs via vascularized bursae in cloaca
-ability to absorb o2 under water through gills in cloaca
living birds are a special type of dinosaur called the theropod dinosaurs - what features do living birds share in common with extinvt theropod dinosaurs
-hollow, pneumatic bones
-elongate, moveable, S-shaped neck
-tridactyl foot (3 toes forward, one back)
-collagen (protein) similarities
explain how molecular phylogenetics links extinct theropod dinosaurs with living birds
-based on collagen protein sequences
-t-rex collagen proteins derived from fossil specimens
-early feathers share B-keratin unique to modern feathers
birds are actually feathered theropod dinosaurs - did feathers originally evolve for flight, or for other functions? what were these possible functions?
-evolved for thermoregulation (retaining body heat)
-social display (NOT FLIGHT)
archaeopteryx is an evolutionary "mosaic" - showing both modern bird-like features, and ancestral "reptilian" features. provide examples of each. why is such evolutionary "mosaicism" expected?
---toothed beak (reptilian character)
---wing claw (reptilian)
---long tail w/ vertebrae
---furcular (wishbone), long foerlimbs w/winglike proportions, asymmetric vaned feathers
-bc intermediate form -> transition from dino to birds
multiple groups of tetrapods have convergently evolved the ability to glide-provide examples. multiple groups of tetrapods have convergently evolved the ability of powered flight - provide examples
----some frogs, lizards & snacks
----some non-bat mammals
----pterosaurs (extinct), birds, bats
birds evolved the ability of powered flight from terrestrial flightless ancestors that possessed features facilitating this transition - what are these features ?
feathers, endothermy, hollow bones, long forelimbs
modern birds radiated ~ 65 million years ago. what major biotic changes were happening on earth at about this time?
-KT Boundary -> adaptive radiation
- mass extinctions
modern birds are classified into two main groups - what are these, and how do these groups differ (in at least one character)? which group of birds would you expect to be larger in size (on average) - why?
-flightness are bigger dont need to minimize their weight to fly
-ratite birds -> flightless birds, flat sternum, ostrich, emu, kiwi
---bigger bc dont have to have hollow bones for flight
-neognathae -> keeled sternum for flight muscle attachment
---pectoralis muscle works antagonistically w/ supracoracoideus muscle
modern birds show tremendous diet breadth - give examples of particulate feeders, herbivores, carnivores, and scavengers. common names will suffice.
-eagle = carnivores
-vultures = scavengers
- parakeets/macaw = herbivores
- diet reflects bill morphology
what are three skull characteristics of an early - diverging synapsid (like Dimetrodon)?
-skull w single temporal fenestra
-jaw articulation formed by articular-quadrate bones
-heterodont -> teeth become more specialized
contrast homodont detention to a heterdont definition
homodont -> same teeth
heterdont -> specialized teeth
living mammals have two defining features that actually evolved in earlier synapsid ancestors - what are these?
-teeth dentition becoming more specialized (heterodont)
-jaw articulation changing inner ears
- these features evolved before mammals
modern mammals radiated - 65 mya. what major biotic changes happening on earth at about this time ?
- global temp increase
- all major living groups present in fossil records at this time
know the three primary geological Eras, including absolutes times that divide these eras
-65 mya KT mass extinction of dinos, bird dinos went cray
----separates cenozoic from mesozoic **meso->middle
- 248 mya end permian mass extinction
----separates Mesozoic and paleozoic
living mammals represent a prime example of an adaptive radiation. what are some aspects of this radiation?
tiny bat and giant blue whale
other mammal species have greatly impacted human history. provide three examples
rats (pathogen), cows, horses, dogs (domestication/companionship), sheep (wool)
what is a primary function for hair? what are other, secondary functions? why arent most marine mammals (e.g., whales and dolphins) hairy??
-prevents heat dissipation from body to the environment, prevents absorption of heat from the environment
-whales and dolphins dont need it
how is hair related to the evolution of lactation
-lactation likely evolved from glandular secretions asociated with hairs
define endothermy. define homeothermy.
endothermy-> have a body temp that is principally dept on internally generated metabolic heat ex. birds
----regulation of body temp by metabolic means
----heat generated from cellular catabolic and anabolic processes
----cellular metabolic heat coming from core organs
homeothermy -> maintain relatively constant internal body temp regardless of ambient temp ex. polar bears
courtship occurs in different "channels" (e.g., visual, acoustic, etc). provide examples of each primary "channel". what is multimodal signaling?
-chemical courtship -> most common form of sexual signaling in animals
----female moth calling using long-distant pheromone-male gradient of chemicals
----male delivers pheromone by slapping female nostrils w/ mental gland
-acoustic courtship -> signaling; species-specific cricket calls
-multimodal signaling -> singing in different pitches to attract a mate
define internal fertilization, explain why such fertilization requires complex adult (e.g., M F) interactions, and why internal fertilization often results in the evolution of intromittent organs?
-eggs fertilized inside of the females body
-male/female courtship -> info exchange b/tw the sexes which leads to reproduction
---chemical, acoustic, visual
-information exchange -> happens via visual, chemical, mechanical signaling
-bird repro -> "cloacal kiss" bc no intromittent organ in majority of male birds, spermatophore
what is the acrosomal reaction, and how do species-specific molecules come into play at this stage
-enables species-specific recognition
-a species specific polysaccharide in the egg jelly binds to the sperm, initiates the acrosomal reaction
-break down of acrosomal membrane through the release of enzymes that digest through egg jelly surface
-surface specific binding proteins, recognized by species specific egg receptor proteins
define chemotaxis, and give a specific example of a chemical involved in chemotaxis
-sperm is attracted to the egg via chemotaxis; where the sperm follows gradient of chemicals secreted by the egg
gametes of marine invertebrates that are external fertilizers face two problems - what are these?
1. tiny gametes find other gametes in this huge place
2. how do gametes recognize conspecific gametes
define external fertilization, and explain why such fertilization is expected to be less common in terrestrial habitats
-haploid eggs fertilized outside F body
-wet or moist areas bc it gives the sperm external mobility to get the egg
where have most instances of facultative parthenogenesis been observed
where the female is isolated (zoos) but also confirmed in nature
how did most instances of obligate parthenogenic lizards originate? what is the benefit of an all female species performing pseudocopulation?
-originate via hybridization via two sexual species
-pseudoco-> leads to larger clutch sizes, determined by hormonal cycles
what is parthenogensis? how are obligate parthenogens different from facultative parthenogenesis?
-involves a combo of asexual + sexual reproduction
-obligate -> only female species, often polyploids
---cant produce sexually at all
- facultative -> observed where a female is isolated, occurs via terminal fusion, where egg nucleus fuses w second polar body and diploidy is restored
---has ability to switch b/tw sexual and partheogenic repro
---a female individual can reproduce via both sexual and asexual reporduction. females can produce viable asexual reproduction. females can produce viable offspring with or without genetic contribution from a male
contrast the dioecious condition to the monoecious condition
-dioecious-> with separate sexes
-monoecious -> (hermaphrodites) single individual with both M & F sex organs
---sequential hermaphrodites -> M vs F gamete production changes during lifetime
what is the evolutionary significance of meiosis
-all haploid gametes are genetically unique and genetically different from the adult
-diploid offspring are novel genotypes, diff from parents
- entire population is genetically variable
- evolutionary response requires genetic variation, sexual populations have greater ability to respond to variable selective pressures
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