Midterm 1 Flashcards
what is the difference between a homocercal tail and a heterocercal tail?
hetero–> two asymmetrical lobes
homo–> equal lobes (produces forward thrust without lift)
Organisms belonging to the phylum Chordata all have what 5 traits at some stage in their life?
- notochord
- pharyngeal gill slit
- subpharyngeal organ (endostyle or thyroid gland)
- a dorsal tubular nerve cord (hollow)
- postanal tail
what is a notochord?
hyrdostatic organ that does not compress, supports the body
what are pharyngeal slits?
- aided in feeding & respiration primitive chordates
- part of the digestive tract
where are the pharyngeal slits?
posterior to the mouth
what is the postanal tail?
posterior elongation of body past the anus
what is the endostyle?
involved in iodine metabolism
- needed to make thyroid hormones
what three things have endostyles?
- urochordates
- cephalochordates
- larval lamprey
what have thyroid glands?
adult lamprey and all other vertebrates
what do chordates include?
all vertbrates along with some primitive sea animals
what do hemichordata have?
- pharyngeal slits
- dorsal nerve chord
what do hemichordates lack?
- post anal tail
- notochord
class ascidiacea
- sac-shaped, enclosed in tunic as adult
- incurrent/excurrent siphon to capture food particles
cephalochrodata
-worm like filter feeders (cilia aid)
- free swimming
-dorsal nerve chord
- pharyngeal gill slits
urochordata
- dorsal nerve chord
- pharyngeal gill slits
-post anal tail - notochord
- filter feeders (cilia aid)
- free swimming
- only larvae
- adults sessile
- adults have a heart no blood vessels
chordata
- dorsal nerve chord
- pharyngeal gill slits
- post anal tail
- notochord
- filter feeder (cilia)
- sexes are separate
-segmented muscle - no heart but blood vessels
evolutionary systematics
places organisms in a common category based on similarities in characteristics
radial (body symmetry)
- body laid out equally from a central axis
- any plane through center divides organism into equal (mirror) parts–> jelly fish
bilateral (body symmetry)
- midsaggital plane divides body into equal parts
frontal plane
bilateral body into dorsal and ventral
saggital plane
bilateral body into left and right
transverse plane
bilateral body into anterior & posterior
anterior
cranial/head
posterior
caudal/tail
dorsal
back
ventral
belly/front
medial
midline of body
lateral
sides of body
distal
farthest
proximal
closest
pectoral region
chest supporting forelimbs
pelvic region
hips supporting hindlimbs
rapid reproduction
unchecked- members of species naturally increase in numbers
carl linnaeus
-systems for grouping and naming animals
- species are fixed and unchanging
theory of evolution darwin vs wallace
wallace: “best fitted to their environment lived”
darwin: 1. unchecked 2. competition for declining resources 3. survival of the few
john ray
- grouped/classified based on characteristics
- modern taxonomy
william paley
- natural theology or evidences of the existence and attributes of the deity collected from the appearance of nature
- watchmaker analogy but recognized the complexity of design
robert hooke
- once living organisms
- document changes over time
- fossils as a historical record
Jean-Baptiste lamarck
- adaptive change
- inherited by subsequent generations
- driven by environmental change over long periods of time
- mixed up physiological characteristics/response
- a ladder of progress
- needs –> traits (giraffe neck)
what was wrong with lamarks theory
- no direction
- do not adapt to achieve an end
- loss of a trait does not occur because of not needing it
lamarckism
the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring –> heritability
thomas malthus
- produce far more offspring than can survive
- population grows geometrically
- food supply grows artithmetically
- unless family size regulated–> decline of humans
Karl Ernst von Baer
- discovered human ovum & oocytes
- established mammals develop from eggs
- species were similar went through similar egg development stages
what did karl baer work allow for?
the primordial ancestor of a group of related organisms from the early embryose of those organisms
ernest haekel
recapitulation
cartilangeous skeleton
- predatory carnivores
- eat commercially valuable fish
- destroy fishing nets
branches splitting means?
different taxa
what is the bird wing evidence of?
reptilian forelimb
homolgy
ancestry
analogy
function
homoplasy
appearance
serial homology
similarity b/w successively repeated parts in the same organism
turtle and dolphin forelimbs similarities
paddle function–> analogous
common ancesteor–> homologous
superficially simialr–> homoplastic
what were feathers originally for?
insulation then modern birds–> flight
phylogenetic relationships
graphic representation of evolutionary relationships
ladder like evolution
several simultaneous courses of all spp pinnacles within own groups all adapted to their own environment
what are evolutionary processes limited by in terms of explaining form and function?
external environment
internal structure
what does morphology include?
form and function structural integration of parts with function analysis at level of organism, organsim’s parts, organism’s niche
what are the physical limitations to design?
designed favoured by natural selection
does natural selection initiate evolutionary changes?
no it acts on choices offered
ex avain wings evolved for flight so they will never be effective for digging
taxonomy
the system of classifying plants and animals by grouping them into categories according to their similarities
phylogeny
the course of evolutionary change within a related group of organisms
phylogenetic tree
a graphical representation of the evolutionary relationship between taxonomic groups
cladistics
organisms categorized based on shared derived characteristics that can be traced to a groups most recent common ancestor and are not present in more distant ancestors
dendogram
branching diagram that represents the relationships (or history) of a group of organisms
how are dendrograms used in computational biology
illustrate clustering of genes or samples
cladogram
shows the cladistic relationship between a number of species
phylogram
illustrates phylogeny, branches proportional to the amount of inferred evolutionary change
what is the linnaean system of classification?
assigns every organism a kingdom, phylum, class, order, family, genus and species
phylogenetic classifications system
names only groups of organisms that are all descended from a common ancestor
what are the advantagous of phylogenetic classification?
- tells you about the organisms evolutionary history
- does not “rank” organisms
- reassigns names based on ancestral links (clades)
- uses biological names doesn’t have to change linnaean names still work
taxa
group of organisms
what do muscles do?
shorten by contraction
origin
where the muscle attaches, the end that doesn’t move
insertion
where the muscle attaches, the end that moves when the muscle contracts
abduct (action)
away from midline
adduct (action)
toward midline
flexion (action)
reduce angle of joint
extension (action)
increase angle
protraction (action)
reduce angle of joint
retration (action)
move limb back
agonist
causes the action
antagonist
resists or causes the counter action
tendons and faschia
connect muscles to bone
ligaments
connect bone to bone
faschia
thin casing (sheets) that surround and hold organs, vessels, nerves as well as muscles
monophyletic taxon (clade)
includes the most recent common ancestor of all those animals and all the descendants of that most recent common ancestor
paraphyletic taxon
includes the most common ancestor does not include descendants of the most common ancestor
polyphyletic taxon
most common ancestor not included, common ancestor lacks the characteristics of the group
-“unnatural”
what are examples of polyphyletic taxon
marine mammals, bipedal mammals, flying vertebrates
synapomorphy
derived or changed character state shared by two or more lineages in a particular clade
what are synapomorphies indicators of?
common ancestory
what is a homology?
similar characteristics shared by two different organisms that were inherited by a common ancestor
what is an example of a homology?
dove–> efficient flyer, ostrich is flightless
both inherited from common ancestor that has wings
what are analogies?
similar characteristics shared by two different organisms because of convergent evolution
what is an example of an analogy?
wing of a dove and the wing of a butterfly
- bird and insect lineages evolved wings separately
what is convergent evolution?
when two distinct lineages evolve a similar characteristic
why does convergent evolution happen?
when both lineages face similar environmental challenges and selective pressures
what are homologies of craniates?
- skull - brain case
- cartilaginous or bony
- encloses the brain and sense organs
- smell, sight and hearing
- olfactory, single then becomes paired
- photoreception, paired lateral outgrowths
- become more complex (lense, muscles, eyelids)
- acoustic/mechanoreception (hearing, balancing, perception)
what are homologies-synap of craniates?
- skull - brain case
- cartilaginous or bony
- encloses the brain and sense organs
- smell, sight and hearing
- olfactory, single then becomes paired
- photoreception, paired lateral outgrowths
- become more complex (lense, muscles, eyelids)
- acoustic/mechanoreception (hearing, balancing, perception)
what are homolgies-synapmorphies of vertebrates?
-series of bone or cartilage blocks firmly joined together
- replaces the notochord as the main structural support
homologies- synpomorphies of jawed vertebrates
jaws , filter feeding, raptorial feeding (predatory)
what is the cranium derived from in craniates?
neural crest cells: cluster of tissue in embryo
craniate synapomorphies: a head
mouth, gills, pharynx, sense organs
craniate synapomorphies: complex sense organ
paired (except in lamprey), nose, eyes, ears, taste (gustatory), lateral line and electroreceptive system
craniate synapomorphies: tripartite brain
process all the info being collected
fore- takes info from the olfactory system
mid- info from eyes and ears
hind- links to dorsal cord and also process inputs digestive, auditory, electroreception
craniate synapomorphies: complex organ system
control and regulation
craniate synapomorphies: muscularization of the all of the gut
differentiated digestive organs
craniate synapomorphies: gills
improved gas transfer
craniate synapomorphies: hemoglobin
improves the efficiency of oxygen transfer
craniate synapomorphies: braincase
protection- bone is made of connective tissue strengthened with Ca phosphate
what pharyngeal modificatiosn were there in craniates? (4)
- gill arches –> developed from wall of pharynx
- gill arches –> became vascularized and are innervated w neurons
- specialized muscle develo
- anterior gill arch evolved to form jaw
what is the subphylum vertebrate defined by?
the vertebral column replacing notochord during embryonic development
8 classes of vertebrate
- fish (bony, cartilagenous, jawless)
- amphibia
- reptiles
- birds
- mammals
what is the vertebral colum?
series of separate bones or cartilage blocks (backbone)
what are intervertebral bodies?
cartilage or fibrous pads that separate vertebrae
what is the structure of the vertebral column?
centrum, notochord becomes integrated with neural and hemal arch (with spines)
what is the purpose of jaws
capture, bite, crush prey
what are the purposes of paired fins?
stability and control
what did the presence of paired fins lead to ?
new habitats, breeding sites, resource exploitation, predator avoidance
what did jaws evolve from?
anterior pharyngeal arches
what group has jaws?
gnathostomes
how do agnathans feed?
-muscular pumping
- “mud grabbers” deposit feeders
- less limitation in size
how did prevertebrates feed?
cilia to produce feeding currents
what is filter feeding?
- encircling band of muscle: squeeze water
- cartilage replaced collagen of pharyngeal bars: spring back to original shape after contraction
- like filter feeders but pump rather than use cilia
how do gnathostomes feed?
- raptorial feeding: pluck individual particles from benthos or suspensions
what did the switch in feeding methods with gnathostomes allow for?
- forecefull expansion of pharyngeal pump: sucking motion
- development of jaw, prevent prey escape
- increased predation= increased size
in later jawed fishes what were the jaws supported by?
hyomanidbular bones
where were teeth derived from?
dermal scales or plates
what are the three believed origins of the jaws?
- hypothetical jawless condition
- mandibular arch functions as jaws
- jaws associated with braincase
what are conodots?
filter feeding with teeth but no jaws
what do ostracoderms have? (7)
- plates of bony armour (head sheilds)
- no jaws
- cartilagenous skeleton
- cellular bone
- fins (not paired)
- muscularized pharynx
- sense organs
what do accelular or aspidine bones lack?
lack enclosed bone cells (typical or early vertebrates)
what are cellular bones?
- cells within the bone matrix (typical of modern vertebrates)
what do placoderms have?
- skin
- bony armour of fused plates (external)
- jaws but no teeth
- thorax of bone
- paired pectoral and pelvic fins
- notochord w neural and hemal arches
- most benthic, some open water predators
what type of feeders are ammocoete?
suspension feeders
what features do petromyzontiformes have?
- rasping tongue
- lack bone
- all spawn in FW
- mouth clings to the bottom/prey
-parasitic forms
aplacental viviparity (length, maturity time male and female, nunber of pups)
- longest gestation of any vertebrates
- 18-24 months
- males reach maturity at 11 yr
- females 19-20 y
- 2-11 pups
what is fusiform?
- flattened head, torpedo shaoed, posteriorly tapered
how many gills do sharks have?
5 linked w pharynx
what is the lateral line?
series of small openings from head to tail
what does the lateral line do?
senses vibration, pressure changes
what are the two parts of the nostril
- incurrent opening
- excurrent opening
what do endolymphatic pores do?
help with balance and orientation
what are the endolymphatic pores attaches to?
ducts that extend from the inner ear
what are the ampullae of lorenzini?
tiny pores in the skin on the head arean (thermoreceptors/electroreceptors)
what are the ampullae of lorenzini responsible for?
specialized sensory functions
what are placoid scaled made of?
dentine/enamel
what is the purpose of the tooth like structure on shark skin?
- to decrease friction
- protection
ray & skate features
- dorsoventrally flattened fish
- large spiracles
- 5 pairs of gill slides
- enlarged pectoral fins - attach to head and body
- elasmobranches
example of rays
pristiformes, myliobatiformes, and torpediniformes
skates have what?
- oviparous egg laying (mermaids purse)
- dorsal fin
- fleshy tail (small fins)
- no spines
- thorny projections
- small teeth
rays have/are what?
- viviparous (live bearing)
- dorsal fin (reduced or absent)
- thin tail with barbs/spines
- plate like teeth- crush prey
- larger than skates
do chimeras have a stomach?
no
what shape are the jaws in chimeras (ghost fish)
aberrant shaped
what are the gills covered by in chimeras ?
operculum
