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163 Cards in this Set
- Front
- Back
Natural Selection
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differential reproductive success - individuals whose characteristics best adapt them to their CURRENT environment are most likely to survive + reproduce
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"fit" individual
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well-adapted to the environment + able to pass along its genes
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population
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a group of individuals - same species, same time, same place
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gene pool
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all alleles in a population (diploid)
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microevolution
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when a given allele frequency changes in a given population over time
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what creates new alleles?
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mutations
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what are the two characteristics of a non-evolving population?
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1. gene pool remains constant (no change in allele frequency)
2. highly theoretical |
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Hardy-Weinberg Principle
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sexual reproduction alone does not lead to microevolution - genetic equilibrium
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directional selection
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when allele frequencies, underlying a range of variation, shift in a consistent direction, in response to a change in the environment
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stabilizing selection
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when intermediate phenotypes are favored and extreme phenotypes at both ends of the range of variation are eliminated
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disruptive selection
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when intermediate phentotypes are selected against and extreme phenotypes are favored
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sexual selection
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when a phenotype that gives an individual an advantage at reproductive success if favored
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balancing selection
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when two or more alleles are maintained at a frequency of greater than 1% over the generation, which tends to favor heterozygotes
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genetic drift
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change in gene pool based on chance, not selection
- small populations |
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bottleneck effect
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reduction in population size when individuals are randomly chosen
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founder effect
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colonization of a new location by only a few individuals by chance
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gene flow
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individuals or gametes are transferred between populations (immigration/emigration)
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mutation
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random change in an organism's DNA
- only creative force |
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Ernst Mayr's Biological Species Concept
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a group of populations whose individuals have the potential to interbreed + produce fertile offspring
- sexual, not asexual |
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temporal isolation
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pre-zygotic reproductive barrier
- whole organisms are not present at same time |
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ecological isolation
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pre-zygotic reproductive barrier
- organisms are not located in same placd |
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behavioral isolation
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pre-zygotic reproductive barrier
- no sexual attraction |
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mechanical isolation
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pre-zygotic reproductive barrier
- unique reproductive parts |
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gamete mortality
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pre-zygotic reproductive barrier
- copulation but no fertilization |
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hybrid inviability
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post-zygotic reproductive barrier
- either no development of embryo or offspring that are frail + weak |
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hybrid sterility
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post-zygotic reproductive barrier
- healthy but sterile offspring |
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allopatric speciation
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physical/geographic barrier
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divergence
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allopatric speciation
1 -> 2 species |
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adaptive radiation
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allopatric speciation
1 -> many species |
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sympatric speciation
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without a geographical barrier
- 3n plants |
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systematics
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study of biological diversity
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phylogeny
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evolutionary history (and relationships) of a group of organisms
- genealogy/tree of life |
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taxonomy
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naming + classification of species
- Linnaeus |
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Domain ...
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Domain Kingdom Phylum Class Order Family Genus Species
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transformation
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taking up of DNA from surrounding fluid
- prokaryote genetic variation |
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trasduction
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phase trasfers a piece of DNA from previous host cell into new host cell
- prokaryote genetic variation |
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conjugation
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direct transfer of replicated DNA from one cell to another
- prokaryote genetic variation |
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chordates
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dorsal neve tube
notochord posterior tail pharyngial gill slits |
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tunicate
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larvae are free-swimming and have all 4 chordata characteristics
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lancelet
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fishlike because it swims and has segmented muscles and has all 4 chordata characteristics
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lamprey
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only surviving vertebrate with just cranium and backbone
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Endosymbiosis Theory
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Lynn Margulis
photosynthesizing bacteria -> chloroplasts aerobic photeobacteria -> mitochondria |
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Vertebrates
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cranium -> backbone -> jaws -> gills
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Fish Characteristics
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aquatic
paired gills for breathing hinged jaws paired fins |
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Fish Types
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Osteichthyes (boney, swim bladder)
Chondrichthyes (cartiledge, move constantly) |
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Amphibian Characteristic
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lungs + diffusion
strong + boney limbs hydration through skin external fertilization eggs require water ectothermic |
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Reptile Characteristics
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overlapping scales for waterproof barrier to prevent dehydration
internal fertilization amniotic eggs ectothermic |
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Bird Characteristics similar to Reptiles
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amniotic eggs
scales (legs) feathers |
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Bird Characteristics
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lightweight - no teeth, honeycombed bones, hollow feathers
wings + flight feathers for lift strong breast muscles endothermy b/c enzymes need to be at constant temp to make ATP 4-chambered heart |
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Mammal Characteristics
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mammary glands
hair 4 types of teeth |
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Mammal Types
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monotremes (amniotic eggs)
Marsupials (embryo in uterus/marsupium) Eutherians (long gestation in uterus) |
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Human Classification
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D - Eukarya
K - Animal P - Chordata subP - Vertebrata C - Mammalia O - Primate F - Hominidae G - Homo S - sapien |
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population size
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# individuals of the species
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population density
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# individuals/unit area
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quadrat sample plots
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average # individuals/plot x total # plots
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capture-recapture
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tagged/N = tagged2/caught
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population distribution
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clumped
uniform random |
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Zero population growth
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birth = death
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Population Growth
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G = r (b-d) x N
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exponential growth model
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unregulated growth of a population under ideal conditions
j-shaped G=rn humans, bacteria |
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logistic growth model
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population growth is slowed by limiting factors as the population increases
s-shaped G=rn(K-N/K) |
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carrying capacity
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K
max population size an environment can support variable because of environmental changes |
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limiting factors on populations
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density dependent - food, space, disease, toxic waste buildup, predation, street
density independent - flood, fire, natural disaster |
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Survivorship Curves
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Type 1 - high death rates in old, few offspring with good parental care, large mammals
Type 2 - intermediate death throughout ages, small mammals and large birds Type 3 - high death rates in young, lots of offspring with no parental care, insects and plants |
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life history + traits
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life history = the adaptations that influence reproduction + account for differences seen in survivor curves
1. age of sexual maturity 2. size of liter 3. frequency of reproduction 4. parental care |
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r-strategists
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Type III survivorship curves
selection for maximum reproduction |
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k-strategists
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Type I and II survivorship curves
select for living at carrying capacity densities |
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demographic transition
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transition from high birth and death rates to low birth and death rates
population keeps growing because death rate falls before birth rate |
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Hierarchy in Ecology
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organisms
populations communities ecosystem biosphere |
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5 types of interspecific interactions in communities
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competition
predation parasitism mutualism commensalism |
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symbiosis
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2 or more species living in close association with each other for part or all of their life cycle
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interspecific competition
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2 species competing for the same resources
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competitive exclusion principle
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Gause
- 2 species competing for the same resources cannot coexist |
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niche
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population's role in the community
- where they live, what they eat, time of feeding |
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2 outcomes of competitive exclusion
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1. extinction for 1 species
2. resource partitioning - evolution through adaptation (NS) where 1 species changes its niche |
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predator
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consumer of another living organism
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prey
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thing eaten by predator
- plant, bacteria, animal, fungi |
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coevolution
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series of reciprocal adaptations of 2 species
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plant adaptations against herbivores
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physical = spines, thorns, silica
chemical = toxins, bad smells/tastes recruitment = bringing in another predator |
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animal adaptations against predators
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mechanical = shells, thorns, horns
chemical = venom, toxins camouflage behavioral = hiss, show teeth, packs/herds mimicry |
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batesian mimicry
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harmless species mimics dangerous one
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mullerian mimicry
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2 harmful species mimic each other to reinforce "danger" idea
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parasitism
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one species benefits while other is negatively effected
- parasite doesn't want to kill host |
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social parasites
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take advantage of social behavior of hosts
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commensalism
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positive to one species and neutral to other
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mutualism
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reciprocal benefits for both species
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4 types of animal tissue
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epithelial
connective - loose (fibers) - dense (tendons, ligaments) - bone, cartilage, blood, adipose muscle - involuntary = cardiac, smooth - voluntary = skeletal nervous |
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epithelial tissue
free surface basement membrane |
sheets that cover external surfaces or line the inside of organs/cavities
- inside cavity or outside surface of skin - side attached to a dense mat of extracellular matrix consisting of fibrous proteins + polysaccharides |
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secretory epithelium
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glandular epithelium
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exocrine
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secretions released onto free surface + carried through ducts/tubes
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endocrine
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no ducts, secrete from free surface directly into body fluid/blood
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simple squamous
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one cell layer, flattened
- diffusion + filtration - aveoli of lungs, capillaries |
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simple cuboidal
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one cell layer, cube-shaped
- secretion + absorption - line kidney + ovaries + testies + various ducts |
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simple columnar
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one cell layer, tall column
- ciliated or microvilli - secretion, movement (cilia), absorption (microvilli) - line airways + digestive system |
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stratified squamos
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several layers of flattened cells
- protection, covers areas of high abrasion - skin, mouth, esophagus |
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what constrains diffusion?
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surface area to volume ratio
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interstitial fluid
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fluid that contains blood vessels containing blood cells
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how do you maximize surface area?
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folds, long + thin body
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homeostasis
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the activities of cells, tissues, organs, + organ systems that keep an organism's steady state in a range that cells can tolerate
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negative feedback
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a control mechanism to prevent small changes from becoming too big
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positive feedback
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amplifies a reaction
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functions of saliva
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- lubrication/mucous
- chemical digestion (amylase breaks down amolose (starch)) - neutralizes acids in food |
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functions of teeth
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mash food (mechanical breakdown)
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functions of tongue
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tastebuds, swallowing
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3 components of oral cavity
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tongue, teeth, saliva
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pharynx
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allows us to swallow without breathing in food
entrance to both the trachea + esophagus |
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esophagus
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smooth muscle contractions bring food through this tube to the stomach in 5 to 10 seconds
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stomach functions
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1. mechanical churning
2. storage 3. produces acid + enzymes for digestion |
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small intestine functions
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1. site for completion of chemical breakdown of all macromolecules
2. absorption of all macromolecules 3. increased surface area |
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pancreas function
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produces enzymes to secrete into the small intestine
1. carbohydrates - pancreatic amylase 2. proteins - trypsin, chymotrypsin, carboxypeptidase 3. lipids - lipase 4. nucleic acids - pancreatic nuclease produces bicarbonate to neutralize the acidity of the chyme coming from the stomach so that the enzymes can work |
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liver function
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produces bile (emulsifies lipids)
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gall bladder function
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stores bile from liver
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large intestine (colon) function
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1. concentrate waste (remove 90%) water
2. storage of waste 3. bacteria (symbiotic - make bacteria) |
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incomplete digestive system
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mouth = anus
- can only digest one meal at a time so animals can't have high metabolic needs |
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complete digestive system
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specialized along its length
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digestive system of birds
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1. pointy beak for picking up seeds
2. crop to store seeds 3. gizzard to grind up seeds since past mouth |
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digestive system of rodents (herbivores)
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1. no gall bladder needed (no animal fat to digest)
2. really large caecum in between small + large intestine - contains bacteria to break down cellulose |
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Digestive system of ruminant animals
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(hooved)
- teeth designed for grinding - four-chambered stomach allows for digestion of fiber -> re-chewing -> digestion again |
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Digestive system of mammalian carnivores
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- gorges itself rapidly and doesn't chew its food
- large stomach - short small intestines |
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open circulatory system
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vessels are open-ended into the body cavity
- no distinction between interstitial fluid and blood - invertebrates (insects, mollusks) |
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closed circulatory system
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(cardiovascular system)
- completely closed network - distinction between interstitial fluid and blood ex. = all vertebrates, some invertebrates (earthworms, squid) one circuit = fish - blood flow is slow after gills two circuits = all other vertebrates - after blood travels through the lungs, it is repumped by the heart 3-chambered heart = not as efficient because highly oxygenated blood returning from the lungs mixes with blood containing a lot of CO2 (amphibians, reptiles) 4-chambered heart = crocodiles, birds, mammals |
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How are CO2 and O2 diffused in the circulatory system?
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along partial pressure gradients (high -> low) in lung alveolar cells + the circulatory system
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What happens to the human body at high altitudes?
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erythroporetin (hormore) is secreted from the kidneys into the bone marrow which produces more RBCs
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How is CO2 transported in the circulatory system?
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10% dissolved in plasma
30% bound to hemoglobin 60% bicarbonate (reversible reaction) (increases pH) |
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Order of blood flow around heart
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heart -> arteries -> arteriole -> capillaries -> venule -> vein -> heart
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Arteries + Arterioles
vasoconstriction vasodialation |
carry blood away from the heart (usually with O2 but not always)
fastest speed (just left the heart) but slows down with distance because of friction + narrower vessles thick smooth muscle cell wall, elastic layers vasoconstriction = smooth muscle cells constrict and increase the blood pressure or act as sphincters to shunt blood flow vasodialation = smooth muscle cells relax |
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Capillaries
ultrafiltration capillary reabsorption |
connect arterioles + venuoles
- don't always have blood in them (smooth muscle cell sphincters in the arterioles control this) slowest speed (exchange) gradient pressure (higher at arteriole end than venule end) simple squamous, designed for exchange - O2 and CO2 by diffusion - other molecules by active transprot or exocytosis/endocytosis ultrafiltration = at the arteriole end of a capillary bed, hydrostatic pressure is higher + plasma is pushed between the 'leaky' endothelial cells capillary reabsorption = at the venule end of the capillary bed, osmosis drives water into vessel (b/c of the higher solute concentration in plasma compared to interstitial fluid) |
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Veins/ Venules
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carry blood to the heart (mostly without O2 but sometimes with)
slow speed but gets faster as it moves toward the heart lowest pressure (furthest from the heart) valves keep blood from flowing backwards |
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Four Chambered Heart
- atria - ventricle - AV valve - semilunar valve |
atria = receive blood from veins
ventricles = receive blood from atria and pump to arteries AV valves = between atrium + ventricle Semilunar valves = between ventricle + artery |
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diastole
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heart is relaxed
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systole
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contraction
- atria contracts (AV valve open, semilunar closed) - ventricle contracts (AV valve close, semilunars open) |
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pulse
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rhythmic stretch of arteries
- measures health/efficiency of heart |
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blood pressure
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force exerted on arteries
1. width of vessels (constriction of smooth muscle or atherosclerosis) 2. volume - change in hydration or blood lose |
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blood pressure healthy
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120/80
hypertension = more than 140/90 measures health of vessels |
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3 cellular components of blood
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RBC, WBC, platlets
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plasma
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90% water, 10% solvent for plasma proteins, ions, molecules, glucose, O2, CO2, N2, lipids, vitamins
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RBC
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flat biconcave discs with nuclei
120 lifespan anemia = too few RBC or hemoglobin, slow oxygen delivery -> slow metabolism polycythemia = too many RBC or hemoglobin, blood more viscous -> increased blood pressure |
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platlets
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membrane-wrapped fragments of cytoplasm
clump together at site of damage + release substances to prolong muscle spasm + attract more platlets |
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fibrinogen
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rod-like plasma proteins
converge as long, insolube threads that stick to exposed collagen fibers at damaged site to form a net that traps blood cells + platlets |
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immunity
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capacity to resist and combat infection
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barrier definition
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prevents pathogen from entering or attacks pathogen with mechanical/chemical defenses
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innate definition
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quick + general
does not change over time (no memory) (non-specific) all animals |
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adaptive definition
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slow-responding + highly specific
memory (faster + more efficient response the second time) vertebrates |
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physical barriers
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protective linings
skin - layered, stratified squamous, dead waxy outer layer |
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mechanical barriers
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trap or flush out pathogens
mucous (respiratory or digestive tract) earwax |
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chemical barriers
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destroy pathogens
urine (acidic) gastric acid (HCl) lysozyme in mucous - enzyme destroys polysaccharides specific to cell wall of bacteria |
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innate - phagocytes
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inject stuff
macrophage - patrol interstitial fluid of tissues, first responders - release soluble signals (cytokines) at attract more phagocyes - engulf bacterium or non-self particle (antigen) to destroy it - alert adaptive immune system (antigen presenting APC), present particles of pathogen to lymphocytes neutrophils = circulate and enter tissues in response to cytokines - "kamikazes" of the immune system, engulf and kill with peroxide + bleach dendritic cells = engulf antigen - alert adaptive immune system (present antigen to it) |
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innate - complement
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positive feedback
1. attract phagocytes to site of infection, like sniffing 2 form membrane to poke holes in bacteria cell walls or plasma membranes 3. coat pathogens to make them easily noticed by phagocytes |
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innate - inflammation
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four signs: painful, swollen, red, hot
trigger?: invasion by pathogen, cytokines, complements effect?: vasodilators (histamine) produced by immune cells -> leaky vessels -> swelling -> pressure on nerves |
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innate - fever
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prostaglandins act on hypothalamus to raise body's thermostat
why? 1. immune cells might work/divide faster 2. some pathogens might be killed |
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Antibody Mediated
effector cell? effect? target? |
B cell (lymphocyte)
produce antibodies extracellular - pathogens circulating in blood and tissues (such as bacteria) |
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antibodies
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soluble proteins that bind antigens
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Cell Mediated
effector cell? effect? target? |
cytotoxic T cell (lymphocyte)
pokes holes in infected cells -> cell death intracellular - body's own cells infected with intracellular pathogens (such as viruses) |
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Commonalities between Antibody Mediated and Cell Mediated
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- requires antigen-presenting cells that have engulfed the pathogen (present fragments of pathogen in MHC-antigen complex)
- antigen presentation activates helper T cell (lymphocyte) which in turn activate the B and T lymphocyte effectors - specificity = lymphocytes that have receptors that recognize only one antigen (unlike innate system) - diversity = there are billions of different lymphocytes each able to recognize one antigen = billions of different antigens recognized by system - memory = a second encounter with an antigen occurs much faster (unlike innate) - self vs. non-self = recognize through surface molecules that one's own body cells are not invaders |
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spermatogenesis
location |
formation of sperm
seminiferous tubules in testes |
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testosterone
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hormone that is essential in sperm formation + is secreted by Leydig cells in the testes
- controlled by negative feedback loops with other hormones secreted by the hypothalamus (GnRH) and pituitary (LH) and (FSH) |
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epididymis
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sperm mature + are stored here
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where do mature sperm travel?
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epididymis -> vas deferens -> urethra
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seminal vesicles
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gland that produces fructose in semen (nourishment)
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prostrate gland
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produces basic/alkaline fluid in semen to counteract urine in the urethra + acidity on the vagina
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bulbourethral gland
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secretes lubricative mucus in semen
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oogenesis
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formation of eggs (takes decades)
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location of oogenesis
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within follicle of ovaries
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