Flashcards in Biology 104 - Exam 3 Deck (130):
- phylum: echinodemata
- bilateral larvae, radial adults, no cephalization, true coelom, complete digestive, no segment, water vascular system
- sea stars, sea cucumbers, sand dollars
water vascular system
system of canals that circulate water
- gas exchange, waste disposal, locomotion, feeding
- phylum: chordata
- 4 characteristics --> notochord, dorsal nerve chord, pharyngeal slits, postanal tale
flexible rod that runs along the back --> spinal discs in humans
dorsal nerve chord
spinal chord and brain
tail (animals i.e. dog/cat), human tail develops away
tunicates and lancelets
- closest modern day representatives of ancestor chordates
- tunicata: sessile adults, free-swimming larvae
- filter feeders
- ectotherms, endoskeleton, slime production
- eat dead/dying animals
- subphyla craniata
- endoskeleton of cartilage/bone including backbone or cranium
- jaws of cartilage or bone, ectotherms, cranium and vertebrae
- simplest chordates that have a layer of support surrounding nerve chord
agile swimmers, most carnivorous, lateral line system
lateral line system
row of sensory organs along body length
flexible cartilage skeleton, thick/fleshy fins, respiration through the gills, adept predators --> poor eyesight, good smell, electrosensors on head to detect movement of animals
common seas/freshwater, skeleton reinforced by hard calcium salts, keen smell/eyesight, lateral line system, operculum
gil chamber flap that allows for movement/no movement
- fins supported by skeletal rays, gas bladder (buoyancy)
- swim bladder assists in respiration, muscular fins supported by stout bones
- lungfishes, coelacanth
- first to inhabit land
- descended from fishes with lungs
- first limbs/lungs --> skeletal support precursor to limbs
- reproduction still tied to water
- adapted to freshwater/land habitats
- improved respiratory organs, circulation, skeleton system, tear glands
- reproduction --> egg + sperm released, metamorphosis
- amniotic egg protected by shell
- non-avian reptiles have dry/scaly skin, kidney's absorb water, well-developed lungs, internal fertilization
- non-avian (ectothermic), birds (endothermic)
- thought to be dinosaur descendants
- powerful breast muscles, keel-like breastbone
- wing shape dependent on habitat
- honeycomb structure of bones makes them light and durable
- some internal organs absent to reduce weight
- high demand for energy --> powerful heart and lungs
- feathers made of keratin --> same as non-avian scales
- insulation, attract mate --> not at all used in flight
- platypus, echidna
- lays eggs --> young hatch --> feeds on the mother
- brief gestation to live birth
- young develop while attached to mother, usually in a pouch
- kangaroos, opossum, koala
- young develop in womb and have live birth
- placenta joins mother to the embryo
- humans, zebra, elephant, dogs, some aquatic animals
- evolved from small tree-dwelling, insect-eating creatures about 65 MYA
- shared characteristics: opposable thumbs, sensitive hands/fingers and toes with flat nails, no claws, close set eyes with binocular vision, large brain
- lorises, pottos, lemurs (Lorids)
- omnivorous, Madagascar/S. Asia/Africa
- Tarsiers: tree-dwelling carnivores
- SE Asia, nocturnal, insectivores
- new world --> arboreal with prehensile tail used for swinging
- old world --> some arboreal without prehensile tail, some ground dwelling
hominids - locomotion
- free swinging, running with large hands/long arms
- bipedalism in humans
- shorter arms, longer/stronger legs, foot bones form support, pelvis supports body, vertebrae adds flexibility in lower back, foramen magnum tucked under skull
hominids - feeding/diet
- skull ridge, size/shape of skull useful
- sagittal crest as point of attachment for jaw muscles
- molars grind, crush, mash food
- size of the jaw bones/protrusion, tooth row curvature
- foremen magnum positioned downward --> upright walking
- large teeth, protruding jaws, skull with sagittal crest
- associated with stone tools
- larger bodies/brains
- smaller teeth, lighter/less protruding jaw/larger skull/brain case
- lighter brow ridges
evolution of humankind through natural selection
- likely spurred by environmental changes
- upright bipedalism --> advantageous in new habitat
- selection pressure i.e. skin pigment
interactions between organisms & the environment (biotic factors + abiotic factors)
advocacy of preservation, restoration, or improvement of the natural environment especially in relation to pollution
contamination of soil, water, or the atmosphere by the discharge of harmful substances
study of how populations interact with the environment
- explore how factors influence age, size, density, growth rate of population
physical location where population members normally live
the number of individuals of a species per unit area or volume of a habitat
- varies among species
- usually estimated by sampling
population births - population deaths
population growth rate
change in population size per unit
how many new organisms are added to the population each year
how many organisms leave/die in the population
probability of surviving to a certain age
- table creates survivorship curve
- usually seen with humans and other large vertebrates
- low mortality rate
- many birds and some mammals
- age dependent mortality --> in the middle
- fish, invertebrates, plants
- high mortality rate
exponential population growth
- number of individuals added increases in proportion to population size
- J-shaped curve
logistic population growth
- population growth slows & levels off as resources become limited
- S-shaped curve
- limit of individuals that a habitat can maintain or accommodate
- growth rate declines as carrying capacity reached
- depends on species/habitat/resources
- those that intensify as population density increases
- individuals compete for resources
- disease prevalence or predation may increase
- typically have more of an effect before independent factors
- those unrelated to population density
- seasonal freezing, fire, floods, storms, environmental changes etc.
organisms strategy for reproduction and survival
- age of first reproduction
- number/size of offspring
- energy cost of reproduction
- parental responsibility
- tend to be short lived, reproduce at early age, many offspring that receive little care
- population growth rate may be high under optimal conditions
- Type III survivorship curve
- plants, many insects
- long lives, mature later, extended parental care
- high probability of surviving
- mammals, some birds, some insects
- Type I & Type II survivorship curves
diagrams that help predict trends in growth
physical space with specific characteristics where organisms live
all the resources required for survival growth & reproduction
- sunlight/sunlight intensity
- light & temperature variation in precipitation via air conduction patterns
relative to the sun, leads to seasonal temperature changes
- Earth: 23.5 degree tilt
warm and cool air cycle
- air first cools, cause water to condense and fall --> rain
We are losing biodiversity through scarce and polluted resources, and a changing climate.
Two major biomes
Primary Producers (terrestrial)
Plants primary producers (determined by climate)
primary producers (aquatic)
phytoplankton are primary producers (determined by physical conditions)
distribution of biomes
depends largely on precipitation and temperature
temp is cold, dry and windy, phytoplankton in ice and ocean water are primary producers.
very cold, dry; subsoil permanently frozen (permafrost); small plants with shallow roots; animals with thick fur; 20% of land surface; less animal diversity in Southern H. than Northern H.
cold and abundantly dry, abundant coniferous trees; some mammals and birds stay year round.
Temperate rain forest
mild winters, cool summers, abundant rain, large conifers, amphibians, mammals, and fish.
Temperate deciduous forest
warm summers, cold winters, consistent rainfall, trees and migratory animals are common, lots of trees.
hot summers, cold winters, moderately moist, summertime drought, fires, grazing prevent tree growth.
Mediterranean shrub land (chaparral)
hot, dry summers, cool, moist winters, fire and drought resistant plants thrive here.
always dry; may be cool or hot, plants store water, and most animals come out at night time.
warm and wet, highest species diversity of all the biomes, lots of herbivores and predators.
occupy largest part of the biosphere, roughly 75% of earth's surface.
Determined by salinity
(Standing bodies of water)
cover less than 1% of the earth, contain .01% of all earth's water supply,
-standing bodies of water: ponds, lakes, rivers, groundwater
-bacteria common in deep waters
-water depth/distance from shore determine distribution of biota
(flowing bodies of water)
support different kinds of life, vary in character from source to downstream
-lakes, rivers, streams
-cold, clear, low in nutrients, swift
-Downstream water collects to create ponds
-consumers use smell rather than eyesight
3% is salt concentration, 97% of earth's water. Source of most rainfall on earth, home to most life on the planet, photosynthesis by marine algae, source of the biosphere's oxygen.
submerged or exposed ocean meets land, conditions vary with tide.
occur in photic zone of warm tropical waters, algae primary producers, support diverse animal life, being destroyed.
freshwater meets ocean water
-salinity ranges depending on tide, usually bordered by mud flats
-biologically productive environment on earth, high in nutrients.
-threats: pollution, altered freshwater inflow, non-native species.
-/- Two or more species try to obtain the same limited resources: shelter, food, water, light, nutrients
Competitive exclusion principal
two species cannot coexist indefinitely in the same niche, one species wins. Exclusion not inevitable, species can agree to resource partitioning
resources used in a different way or at a different time
one species lives in or on another species (mutualism, commensalism, parasitism)
+/+ benefits both species, improves reproduction
+/0 one species benefits while the other species is unaffected
-/+ one species benefits at the expense of another
some species eat other species for energy and carbon
eat plants for energy and carbon
feeding on other organisms has negative effects on fitness. plants have adaptations such as: thorns, sap, distasteful, or poisonous
animals: camouflage, coloration, mimicry.
coevolution between species
adaptation in one species select for adaptation in another, species evolve in response to another
predators that help save one species by eating the predatory species of that species
total # of species in a habitat
the proportion of a community that each species occupies
process of gradual change in a community
occurs in an area where no life previously existed
is caused by disturbances that disrupt biological communities
-disturbances destroy organisms, alter resource availability
first to colonize, determines other species
-rapid reproduction, efficient dispersal
small-scale disturbances create patchy distribution of succession across a landscapr
1. energy flow through an ecosystem
2. chemical cycling between abiotic and biotic
food chains/ webs
a series of organisms that successively eat one another.
many energy and nutrient transfers
position of an organisms in a food chain relative to energy source
producers-primary consumers-secondary consumers-tertiary consumers then all the waste= detritus and the decomposers eat that then break it down and the cycle starts again.
tiny fraction converted to chemical energy. most absorbed, scattered, reflected by earth's atmosphere or surface
algae, plants: fix energy as it enters an ecosystem (gross primary productivity).
used for building biomass and reproduction
gross primary productivity- heat= net primary productivity.
heat is lost
depends on water availability and temperature
depends on nutrient availability
one tenth of the energy at one trophic level is available in the next trophic level.
at every conversion heat is lost
inefficiently get energy from what producers fix.
-10% rule varies- more like 2%-30%
-depends on digestibility and metabolic rate
chemicals in biomass at a low level can be more concentrated at higher levels.
pesticide used to kill lice and mosquitos in the 1960's.
chemicals that are more likely to become concentrated.
recycling of elements between biotic and abiotic components.
four major reservoirs
Atmosphere, water, organisms, rocks/soil.
an element may combine with other elements.
some cycling relies only on geologic processes, bypassing the biotic (water cycle).
producers/ consumers take up water from lake, river, pond, groundwater; they lose water by cellular respiration.
element critical to life
atmospheric CO2-photosynthesis converts CO2 to glucose- producers fix CO2-consumers eat-organic matter in soil broken down by decomposers- respiration returns CO2 to atmosphere.
atmosphere+oceans= slow cycle
rocks and soil+atmosphere=fast cycle
dissolves in ocean- photosynthesis-aquatic food chain-respiration-back to atmosphere
essential element, needed for creation of amino acids. 18% of atmosphere
nitrogen fixation-bacteria and archaea fix to NH4. nitrates produce lightning
convert NO3- NO2 happens in oxygen poor environments. Combustion happens through industry
erosion (abiotic) releases phosphorus from rocks and sediments- decomposition returns it.
phosphorus dissolved-sedimentations-ocean sediments
too much applied causes pollution
needed for nucleotides, released by weathering
1. Variety of ecosystems
2. variety of species within a community
3. Variety within the genes of each species
loss of diversity limits potential new discoveries
immediate high extinction risk
likely to become extinct soon
losing a species, today 200 of 20,000 gone extinct. 20% freshwater fish gone extinct.