Final Flashcards
Biosphere
Global ecosystem Sum of all the planets ecosystems
Ecology
Scientific study of the interactions between organisms and the environment
Global Ecology
Examine influence of energy and materials on organisms across biosphere
Landscape
Mosaic of connected ecosystems
Ecosystem
Community of organisms in an area and the physical factors which they interact
Community
Group of populations of different species in an area
Populations
Group of individuals of same species living in an area
Organismal Ecology
Studies how and organisms structure, physiology, and behavior meet environmental challenges
Climate
Long term prevailing weather conditions
Biotic Factors
Interactions with other species Predation Competition
Abiotic Factors
Vary in space and time Temperature Water Sunlight Wind Rocks (nutrients)
Temperature
Cells freeze below 0 C Proteins denature above 45 C Mammals and birds expend energy to regulate temp
Water
Availability effects species distribution
Salinity
Salt concentration affects water balance of organisms High salinity is dangerous for most species
Sunlight
Light intensity and quality affect photosynthesis Water absorbs light, therefore most photosynthesis happens near surface High sunlight can lead to high heat stress
Rocks and Soil
Physical structure, pH, and mineral consumption affect animals and plants
Global Climate
Each hemisphere has number of distinct climate zones with characteristic weather patterns
Global Climate Patterns
Determined by solar energy and Earths movement in space Warming effect of sun causes temperature variations and air/water circulation
Latitudinal Sunlight Variation
Angle of sunlight affects intensity Intensity is strongest in tropics (23.5 degrees N and S)
Global Air Circulation
Water evaporates in tropics Warm wet air masses flow from tropics to poles Rising wet air masses release water and cause lots of rain at tropics Dry descending air creates arid climates at 30 N/S This air flow creates predictable wind Cooling Trade Winds and Westerlies Creates wet zones at equator and arid zones at 30 N/S
Cooling Trade Winds
From 30 S to 30 N Blow to west from east
Westerlies
30 N/S to 60 N/S Blow To east from west
Air Pressure
Global air circulation creates predictable pressure zones High pressure zones at 30 N/S Low Pressure at equator
Seasonality
Seasonal variations in light and temp increase towards pole Caused by tilt of axis
Gulf Stream
Carries warm water from equator to N. Atlantic Oceans and lakes moderate temp of nearby terrestrial areas
Biomes
Major life zones characterized by vegetation type or physical environment Distribution affected by climate
Vertical Layering
Feature of terrestrial biomes Consists of upper canopy, low tree layer, shrub understory, ground layer, forest floor, and root Layering provides diver habitats Highest number of species in biomes with large layering (i.e. Rainforest)
Tropical Forest
Equatorial and sub equatorial Constant rainfall Little seasonal variation Vertical layered Competition for light Large species number
Northern Coniferous Forest
North America and Eurasia Largest terrestrial biome Varying precipitation Hot summers, cold winters Face logging from humans
Temperate Broadleaf Forest
Mid latitudes northern hemisphere Significant precipitation in summer and winter Winters near freezing, summers hot and humid Vertical layering Heavily settled by humans
Savanna
Equatorial and sub equatorial Seasonal precipitation. Long dry seasons Typical 24-29 C, but more variation than rainforest Human fires may maintain this biome
Dersert
Bands near 30 N/S Low variable precipitation Hot or cold varying on area Urbanization and irrigation reduce diversity
Temperate Grassland
Semi arid areas Highly seasonal precipitation Winters are cold and dry, summers hot and wet Often converted to farmlands
Tundra
Expansive arctic areas Low precipitation Winters are very cold, summers are cool Focus of oil and mineral mining
Permafrost
Permanently frozen layer of soil Restricts root growth
Aquatic Stratification
Layers defined by light/heat penetration Photic zone- area light hits Aphotic zone- area light doesn’t reach Benthic zone- sea/lake floor
Thermocline
Temperature boundary separating upper warm layer and lower cold layer
Turnover
Semi-annual mixing of water in lakes and oceans Mixes oxygenated surface water with nutrient rich bottom water
Water Density
Water has greatest density at 4 C
Thermocline Circulation
Circulation of ocean water driven by temp and salinity Cold water is denser than warm water Water w/ greater density is more salty Creates a global current that move water from ocean basins to ocean depths
Photic Zone
Zone that receives enough light for photosynthesis
Benthic Zone
Organic and inorganic sediment at bottom of any aquatic body
Detritus
Dead organic matter falls from photic zone and becomes Important food source
Phytoplankton
Single celled organisms that produce photosynthesis at open ocean Also produce biological pump for carbon
Limiting Factors for Primary Production
Controlled by light and nutrients Depth of light penetration Limiting nutrient (nitrogen or phosphorus) must be added to increase areas production
Biogeochemical Cycles
Nutrient cycle in ecosystems involving biotic and abiotic components
Food Chain Length
Energetic hypothesis- limited by inefficient energy transfer Dynamic Stability Hypothesis- long food chains less stable than short ones Energetic is more supported
Trophic Transfers
Percentage of production transferred from one Trophic level to another Typically 5-20%
Dominant Species
Species most abundant or have highest biomass Are either competitively superior or more successful at avoiding predators
Keystone Species
Exert strong control on community by their niche Not necessarily most abundant Often predators or ecosystem engineers
Foundation Species
Cause physical change in ecosystem that affects community structure
Non-Equilibrium Model
Communities are constantly changing after being buffeted by disturbances
Disturbance
Event that changes a community, removes organisms, alters resources
Intermediate Disturbance Hypothesis
Moderate levels of disturbance foster greater diversity than high or low levels of disturbance
Water Cycle
Water moves by process of evaporation, transpiration, condensation, precipitation, and movement
Carbon Cycle
Photosynthetic organisms convert CO2 to organic molecules
Carbon Cycle Diagram
Water Cycle Diagram
Nitrogen Cycle Diagram
Keeling Curve
CO2 concentration is rising with time
Measured over the last 47 years
Marine Biome Challenges
Temperature Increases
Salinity Increases
Sea Level Rises
Ocean Acidification
Increase in low Oxygen Environments
Ocean Acidification
More CO2 in atm leads to more dissolved CO2
Dissolved CO2 makes ocean acidic
Ocean acidity impacts calcium carbonate shells
Allele
Alternative version of a gene
Pedigree Tips
recessive traits often skip generations
for an offspring to be dominant, one parent must be affected
If more males than females its sex llnked
equal genders affected its autosomal
Law of Segregation
two alleles for a heritable character segregate during gamete formation and end in different gametes
Law of Independent Assortment
each pair of alleles segregate independently of each other during gamete formation
True Breeding
Offspring have same variety as parents
Linked Genes
genes located on same chromosome
tend to be inherited together
results deviate from Mendels Law of Segregation
Hershey and Chase
determined DNA was genetic material
studied a bacteriaphage using marked DNA and proteins to determine which was inserted into bacteria
Darwins Observations
1) members of populations often vary greatly in trats and some traits are inheritable
2) all of species are capable of producing more offspring than their environment can support. Therefore many offspring fail to survive
Darwins Inferences
1) Individuals whose inherited traits give them a higher survival probability and reproduce more tend to leave more offspring
2) Unequal ability of individuals to survive and reporduce leads to accumulation of favorable traits in populations
Arguments against Evolution
- evolution cant be observed
- There are no transition fossils
- Chance cant create complexity
- Irreducable complexity
- Violate 2nd Law of Thermo
Evolution Evidence
- direct observation
- homologous characters
- Vestigial Traits
=Fossil Record
Vestigial Traits
historical remnants of traits important for ancestors
Hardy Weinberg
used to test evolution of population
Assumptions:
1) No selection
2) No Mutation
3) No Migration
4) Infinitely Large Population
5) Random Mating
Polyploid
more than two sets of chromosomes
results in instant speciation
Individual Beliefs
Aristotle- fixed life forms, Scala Naturae
Linnaeus- Classification system
Cuvier- Catastrophist
Hutton and Lyell- Gradualism
Lamarck- Inheritance of aquired traits
Wallace- Came up with theory similar to Darwin
Malthus- Carrying Capacity of Earth
Darwin Myths
No first to propose evolution
Not study finches on Galapagos
Documented artificial selection
not a theory about origin of life
not opposed to church
Mutations
point
insertions/deletions
gene duplications
chromosome inversions
polypoloids
Evolution Processes
Natural Selection- adaptive evolution
Genetic Drift- founder effect or bottleneck, maladaptive evolution
Gene Flow- movement of alleles between populations, reduces pop. differences
Stabalizing Selection
selects against both extremes
Directional Selection
favors against one extreme
Disruptive Selection
selects against the intermediate
Pre-zygotic Barriers
Habitat Isolation-difference in habitat
Temporal Isolation-reproduce at diff. times
Behavior Isolation-diff. courtship behaviors
Mechanical Isolation- “parts don’t match”
Gametic Isolation-sperm fails to fertilize
Post-Zygotic Barriers
Reduced Hybrid Viability- impair offspring development
Reduced Hybrid Fertility- offspring is sterile
Hybrid Breakdown- first generation viable, but 2nd is sterile or weak
Modes of Speciation
Allopatric- gene flow impeded by physical barrier
Sympatric- takes place in overlapping geography
Homeotic Genes
control body plans by controlling the developmental fate of groups of cells
Homoplasy
structure appears in diff. organisms due to convergent evolution
Homology
structure in diff. organisms due to common ancestor
Classification System
Domain, Kingdon, Phylum, Class, Order, Family, Genus, Species
“Deranged Killer Pigs Can Offend Freakish Giant Sloths”
Homologous Genes
Orthologous- produced by speciation events
Paralogous- produced by gene duplication events
Molecular Clock
can track evolutionary tree in molecular phylogeny
assumes neutral theory
imprecise/varies among genes/needs calibration
Neutral Theory
States much evolutionary change in genes has no effect on fitness, not influenced by natural selection
Rates of molecular change regulate like a clock
Proximate Question
“How” behavior questions
focus on genetic, physiological mechanisms
Ultimate Questions
address evolutionary significance of behavior
Fixed Action Patterns
innate and sterypyed
unlearned
carried to completion once started
Incomplete Dominance
Phenotype of offspring is intermediate between two alleles
Inclusive Fitness
Explains altruistic behavior.
Individuals favor genes by protecting close family
Ecosystem Services
species do this for free. These benefit humananity
Ex: pollination, nutrient cycle, detox of decompisiton
Evolutionary Reasons for Sickness
time lab between host and pathogen
arms race between host and pathogen
Selection favors reporductive success regardless of other effects
Conditions for Early Life
1) abiotic synthesis of small organic molecules
2) assembly into biological macromolecules
3) Packaging of molecules into vessicles (protocells)
3) origin of self replicating molecule
Miller and Urey Experiment
simulated hypothetical conditions of early life
used H2O, H2, CH4 and electricity to produce small biological molecules
Fossil
Hard parts
Abundunt/Widespread
Existed for Long Time
Snowball Earth Hypothesis
life restricted to hot places (vents, equator)
earth warming lead to Cambrian Explosion
Oxygen Revolution~
~2.7 bya
photosynthetic organisms produced O2
allowed opportunity for respiration
Cambrian Explosion
530 mya
predator prey relationships
E\
Serial Endosymbiosis
explains origins of mitochondria and plastids
primary endosymbiosis- larger cell engulfs smaller cell that provide benefit for both cells
Secondary endosymbiosis- product of primary endosymbiosis is engulfed
Bacterial Cell Wall
Made of peptidoglycan
Gram Negative
thin layer of peptidoglycan
extra cell membrane layer
light purple/pink after gram stain
Gram Positive
thicker peptidoglycan
one cell membrane
dark purple/blue after stain
Prokaryotic Genetic Diversity
due to mutation, rapid reproduction, genetic recombination
Transformation
uptake of DNA from environment and incorporated into genome
Transduction
movement of genes between bacteria by bacteriaphage
virus attacks bacteria, as virus forms new bacteriaphages, bacteria DNA is put into new bacteriaphage and transferred to new bacteria cell
Conjugation
process where genetic material is transferred between prokaryotic cells
transfer is one way
donor cell attaches to recipient by sex pilus
F factor is required for production of pili
Conjugation Steps
F+ cell forms sex pili w/ F- cell
one stand of plasmid DNA enters F- cell and both strands begin to replicate
F+ plasmid circularized and sex pilus breaks down
results in two F+ cells
Chemotrophs
obtain energy from chemicals
Autotrophs
require CO2 as carbon source
Heterotrophs
require organic nutriet to make organic compounds
Lytic Cycle
1) attachment of virus to cell surface
2) Injection- virus attaches to cell surface
3) Synthesis of viral component
4) Assembly of new virus
5) lysis- release new virus
Lysogenic Cycle
1) attachment
2) Injection
3) Integration of viral DNA into host cell; cell replicates virus with cell DNA
4) environmental stressor triggers lytic cycle
HIV Replication Cycle
1) evelope glycoproteins allow virus to attach to white blood cells
2) virus fuses w/ cell membrane and inserts viral RNA and reverse transcriptase
3) Reverse transcriptase synthesizes DNA from RNA
4) dsDNA is integrated into host cell genome
5) environmental stressor causes provirus, DNA is translated and transcribed. Viral glycoproteins insert into host cell membrane
6) vrial RNA from transcription is package w/ reverse transcriptase
7) Viral glycoproteins inserted into cell membrane
8) capsid assembly
9) budding
Marine Viruses
most abundant biological entities
shape aquatic communities
marine food webs
source of mortality for many microorganisms
enhance transfer of microbial cells
Fimbriae
hair like appendages allow for attachment to substrate
Excavata
Groove on one side for feeding, modified mitochondria, unique flagella
SAR
members make up biological carbon pump and marine sediments
Giardia
coat digestive tract
Diatoms
unicellular
glass walls of hydrated silica
phytoplankton
carbon pump
Dinoflagellates
armored cellulose plates w/ flagella in groove
cause red tides
toxic to large ecosystems
kill phytoplankton
Apicomplexan
parasites
cause malaria
ex: Plasmodium Falciperum (malaria)
Dictyostellium discoideum
form fruiting bodies
have bacteria farmers
cheaters who only form fruiting bodies (non-cheaters won’t interact)
Malaria Life Cycle
1) mosquito bitesinfects human w/ sporozoids
2) sporozoids in blood stream, enter and infect hepatophytes
3) divide into morozoites. Upe apical to infect red blood cells
4) morozoites divide asexually w/ red blood cell. Lyse RBC’s and release toxins
5) some become gametocytes in blood stream
6) Another mosquito bites and picks up gametocytes
7) gametocytes differenciate into male and female and fertilize
8) zygote inveds and produces thousands of sporozoites
9) sporozoites go into saliva gland, repeat
Fungi
decomposers, parasites, symbionts
chitin cell walls
heterotrophic
reproduce sexually or asexually
more closely related to animals than plants
Mycorrhizae
mutually beneficial association between plants and fungi
specialized hyphae- haustoria
penetrate plant cell wall and steal nutrients, while helping plant absorb water and minerals
Ectomycorrhizae-10% plants, sheaths over roots
Endomycorrizae- 85% plants, extend through cell walls over cell membrane
Plasmogeny
union of two mycelia, nucleus don’d fuse until karyogamy
Endophytes
live inside leaves and make toxins to deter predators
Lichen
symbiotic association of microorganisms held by fungal hyphae
usually cyanobacteria
Mechanisms for Larger Plant Size
- formation of colonies and filamentous masses
- formation of true multicellular bodies by cell division and differentiation
- repeated division of nuclei with no cytoplasmic division
Derived Traits of Land Plants
apical meristem
walled spores
multicellular gemetica
alternation of generations
Bryophytes
mosses
nonvascular plants
flagellated sperm
gametophyte dominant
Lycophytes
Vascular Plants
sporophyte dominant
club mosses
Derived Characteristics of Seed Plants
seeds
reduced gametophyte stage
heterospory
ovules
pollen
Advantages of Reduced Gametophytes
protection- UV, Dessication
Obtain energy from sporophyte
Transpiration
loss of water from leaves through stomata
Phloem
consists of living cells and distributes organic products
Diffusion Pathways
Apoplast- through cells walls
Symplast-through cytoplasm using plasmodesmata
Transmembrane- uses both apoplastic and symplastic route
Cephalochordata adn Urochordata
Notochord, dorsal hollow nerve cord, pharyngeal slits, muscular post-anal tail
Cyclostomes
vertebrae (2 or more Hox gene sets
Gnathostomes
Jaws, mineralized skeletons
Osteichthyans
Lungs or lung derivatives
Lobe-Fins
Lobed Fins
Amphibia
Limbs w/ digits
Amniotes
Amniotic Egg
Mammalia
Milk
Order of Vertebrate Clade
Cephalochordata and Urochordata
Cyclostomes
Gnathostomes
Osteichthyans
Lobe-Fins
Amphibia
Reptilia
Mammalia
Amphibians
both aquatic and terrestrial
need moist environment for gas exchange
external fertilization
declining populations due to disease fungus, pollution, habitat loss
Reptilians
four layered amniotic egg
Shelled eggs
internal fertilization
keratin scales
exothermic (except birds)
birdes derived from theropods
Mammalians
Amniotes w/ hair and produce milk
high metabolic rate
endothermic
Eutherian, monotremes, marsupials
Evolved form synapsids
Animal
MulticellularHeterotrophicNo cell wallEukaryoticCell specializationTissues
Animal Diversification
Ecological Causes- predator prey relationshipsGeological Causes- more atmospheric O2Genetical Causes- duplication of Hox genes
Animal Egg after Fertilization
Produce Zygote Cleavage8 Cell StageBlastulaGastrolation (Folds in) Form Gastrula w/ endoderm and ectoderm.
Cambrian Explosion
530 myaLead to bilaterians
Grade
Group whose members share key biological featuresNot necessarily a clade
Clade
Group that includes ancestral species and all its descendants
Derived Chordate Traits
Dorsal Hollow Nerve CordNotochordPharyngeal gill slitsPost Anal tail
Urochordata
Chordate larval stageSea squirts
Derived Characteristics of Vertebrates
Vertebrae enclosing a spinal cordElaborate skullFin Rays
Chondrichthyes
Jawed fishesAllows firm grasp on foodFlexible skeletons of cartilageLoss of bone in sharks is derived trait
Oviparous
Eggs hatch outside the mothers body
Ovoviviparous
Embryo develops within uterus nourished by by egg yolk
Viviparous
Embryo develops within uterus and is nourished though placenta
Jaws/Paired Finned Advantages
Jaws allow gripping and slicing of foodPaired fins allow accurate maneuverability
Coelacanths
Living fossils
Lung Fish
Have gills and lungsGulp air into lungs
Tetrapods
Gnathosomes that have limbsFour limbs, feet w/ digitsNeckFusion of pelvic girdle to backboneAbsence of gillsEars
Tiktaalik
Missing link exhibiting both fish and tetrapod characteristics
Amphibians Water Dependence
Need moist skin for gas exchangeEggs lack shells and dehydrate quicklyExternal egg fertilization
Amniotes
Terrestrially adapted eggIncludes reptiles, birds and mammals
Amnion
Thin innermost membranous sac enclosing embryo
Chorion
Outermost membranous sac enclosing the embryo
Yolk Sac
Membranous structure that functions as circulatory system in mammal embryos until heart is functional
Allantois
Vascular fetal membrane that develops from hind gut in higher vertebrates
Albumen
Water soluble protein found in animal tissues and liquids
Ectothermic
Regulate body temp through behavioral adaptations
Endothermic
Keep body warm by metabolism
Turtles
Boxlike shellClosest relatives of the parareptiles
Derived Characters of Birds
Wings w/ keratin feathersLack urinary bladderFemales w/ one ovaryLoss of teethEnhanced eyesight
Monotremes
Small group of egg laying mammals
Marsupials
Have nipplesEmbryo develops in placentaCompletes embryonic development in marsupium
Primates
Hands and feet for graspingLarger brains and shorter jawsForward facing eyesComplex social interactions
Derived Characteristics of Apes
Apes larger than monkeysSexual dimorphismCapable of brachiating
Derived Human Characteristics
Humans stand upright on two legsLarger brains capable of language and complex toolsReduced jawbones and digestive tract
Hominoid
Family containing apes and humans collectively
Hominin
Refers to humans and extinct close relativesOrganisms more closely related to humans than chimps
