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BIOL 202 MIDTERM Cheat Sheet by

Week 1 (Chapter 1) - Studying ecology

Definition of Ecology
the study of how organisms interact with each other and their enviro­nment
Hierar­chical Nature of Ecology
indivi­dual, popula­tion, community, ecosystem, landscape, biome, biosphere
Different Approach to Studying Ecology
1. natural 2. field 3. semi-field 4. lab
Hypothesis Testing
cant be proven, prediction can be true but you can only falsify a hypothesis
2 Approaches to Hypothesis Testing
1. observ­ational 2. experi­emental

The Terres­trial Enviro­nment

Requir­ements to Life on Land
desicc­ation, gravity, temper­ature fluctu­ation
Light in Forests
sunflecks are unaltered light on forest floor, 70-80% of light reaching forest floor
Soil Properties
colour indicates soil proper­ties, texture affects pore space, parent material, vegetation
Soil Moisture
saturated pore cant hold more water, field capacity is the amount of water the soil holds when saturated, capilary water is hte water held between soil particles by capillary force, wiliting point is when plant can no longer extract water, available water capacity is the difference between field capacity and wilting point
Soil Ion Exchange
ion exchange capacity is the total number of charged sites, clay and humus are negatively charged, cation exchange capacity is the total number of negatively charged sites in soil

The Water Cycle

Properties of Water
hydrogen atoms are asymme­tri­cally bonded and form covalent bonds, polar, H bonds break or form to release or obtain energy, less dense as a solid, insulates, cohesion, surface tension, viscosity
The Water Cycle
water covers 75& of earth
Hydrologic Cycle
process by which water cycles from atmosphere to earths surface and back (driven by solar radiation (evapo­rat­ion))
Water Vapour
precip­itates and enters the cycles; interc­eption, ground­water, infilt­ration, evapot­ran­spi­ration
only longwave can penetrate shallow depths, coral and deep water algae dont get red light
heat from sun si distri­buted vertically as wind and surface waves mix
zone where temper­ature declines most rapidly, located between epilimnion and hypoli­mnion

Week 4-5 (Chapter 5-6)

is a trait with a current functional role in the life of an organism that is maintained and evolved by means of natural selection
Natural Selection
different success in survival and reprod­uction of indivi­duals that reflect their intera­ctions with the enviro­nment, evolution by natural selection requires? variation, excess offspring, death of offspring, best offspring survive, variabel trait that allows for better survival and reprod­uction
measur­able, graudal chnage over a geographic region in the mean of a phenotypic trait associated with an enviro­nment gradient
population adapted to unique local conditions
a taxonomic category that ranks below species, usually a fairly permanent geogra­phi­cally isolated race.
Phenotypic Plasticity
the ability of a gene to express itself differ­ently in response to the enviro­nment - s election is for plasticity not the trait
Stabil­izing Selection
mean value of the trait is favoured, phenotype near the mean has the most fitness, most common type of selection
Direct­ional Selection
extreme value of a trait is favoured
Disruptive Selection
members of a population are subjected to different selective pressures
Adaptive Radiation
one species gives rise to multiple species that exploit different features of an enviro­nment (food,­hab­itat)
Genetic Drift
random chnages in allele frequency usually due to small population size
Founders Effect
few indivi­duals colonize an area - their genes, good or bad are passed on
Non-Random Mating
an individual chooses it's mates based on a phenotypic character (assortive mating), mating can be with similar mates or dissim­ilar, or can come about due to female mate choice
Gene Variation is Affected By
1) mutation 2) genetic drift 3) gene flow 4) non-random mating

Plant Adapta­tions

go through the Calvin cycle, taking in carbon dioxide through the leaves' minuscule pores, called stomata. An enzyme called RuBisCO helps the carbon dioxide combine with sugar.
enzyme builds sugars - costly to make
max net photos­ynt­hesis
gross photos­ynt­hesis - respir­ation
driven by atmosphere evapor­ative demand, how water is lost
release H2O and CO2
water use efficiency
ratio of carbon fixed (photo­syn­thesis) per unit of H2O transpired - terres­trial plants balance CO2 intake with water loss - drought tolerant plants have a higher WUE
water potential
H2O movement is a function of differ­ences Y atm < Y leaf< Y root < Y soil
boundry layer
layer of still air (or water) adjacent to the leaf surface
carbon allocation
stem - support and encounter sunlight root - uptake of water, nutrients and storage leaf - photos­ynt­hesis, roots =increase in H2O and nutrients uptake but lowers carbon allocation to leaves, leaves = increase access to light and CO2 but decrease H2O and nutrient uptake, Low soil water plants can allocate more carbon to roots
light compen­sation point (LCP)
net photos­ynt­hesis is zero (available PAR mean net net photos­ynt­hesis is zero)
light saturated point (LSP)
no furthur increase in photos­ynt­hesis (an increase in PAR will not increase the photos­ynt­hetic rate
photos­ynt­hesis and respir­ation respond variations in leaf temper­ature, both increase with temper­ature
demand for water is linked to temper­ature, plants balance water concen­tration by opening and closing stomata
C4 plants are divided between mesophyll and bundle sheath cells. Two steps of C4 photos­ynt­hesis that occur in the mesophyll cells are the light-­dep­endent reactions and a prelim­inary fixation of CO2 into a molecule called malate.
photos­ynt­hesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid condit­ions. In a plant using full CAM, the stomata in the leaves remain shut during the day to reduce evapot­ran­spi­ration, but open at night to collect carbon dioxide (CO2).
macro and micro nutrients, plant nutrients are related to metabolic processes, availa­bility of nutrients influences plant survival, growth and reprod­uction

Week 2-3 (Chapters 3-4)

How Solar Radiation Reaches Earth
solar radiation will enter either via long or short wave radiation from the sun. It can be UV, infrared or visible light. Input of 51 shot and 96 long and then output of 30 evapor­ate­d/t­hermals and 117 radiated from earths surface.
Seasonal and Latitu­dinal Variation in Solar Radiation
the steeper angle means sunlight spreads over larger area, sunlight travels through deeper air layer. rotation causes day and light whereas inclin­ation causes seasons and day length. seasonal variation is solar energy is greatest at high latitudes, solar radiation down with up latitude
Ocean Currents
arise from wind belts which succeed each other latitu­din­ally, easterlies = NH-NE and SH-SE, westerlies = NH-SW and SH-NW, polar easterlies = winds move masses of H2O which get deflected by coriolis,
El Nino
monsoons are reduced (water warmer = less pressure differ­ence)
Ocean Gyres
wind driven ocean currents are deflected by coriolis in gyres, clockwise in NH(R), counte­rcl­ockwise in RH(L)
Adiabatic Lapse Rate
rate of temper­ature changes with elevation (depends on humidity) dry air cools quickly
Adiabatic Cooling
heat loss due to air expanding (with altitude)
As Altitude Goes Down
pressure and density decrease
Air Masses
they are not static: temper­ature causes air to rise and sink
Coriolis Effect
earths rotation causes water and air to deflect, law of angular motion
Intert­ropical Conver­gence
heat from sun causes air to rise (low pressure)
Air and Water in Northern Hemisphere
Air and Water in Southern Hemisphere
Atmosp­heric Moisture
sun warms air at equator, warm moist air rises - air fills low pressure, rising air condenses at tropos­phere - rain forests, air hits top of tropos­phere and moves north and south, cold and dry air sinks at 30º - warm as it sinks (no conden­sation - no rain - desserts)
land warms in summer , air rises and cools, relatively cols moist air from the sea rushes in rises, condense and rains, warm and wind
Vapour Pressure
as water cools it must condense to maintain vapour pressure (aka fogs/c­louds)
El Nino Conditions
1. trade wins carry water and air to Australia 2. high pressure off peru, low pressure off Australia 3. upwelling off peru 4. Australia wet - peru dry

Week 6-7 (Chapter 9-11)

individual produced by sexual reprod­uction
produced by sexual reprod­uction
random, clumped and uniform, abundance estimates may be skewed by spatial distri­bution
Geographic range
range of expansion is the result for popula­tions introduced to a region where they did not previously exist
how many per unit area
often tells you something about the ecology of the species
Age Structure
proportin of indivi­duals in different age classes
movement of indivi­duals away from place of birth (usually to vacant habitats)
two way seasonal movement usually predic­table
age class
number of indivi­duals in that age class
proportion of original cohort surviving to that age
number that died (sometimes a portion)
dx/nx, age specific mortality rate
mean number born in each age class
Type 1
survival high throughout life, heavy mortality at end (K)
Type 2
survival doesn't vary with age
Type 3
mortality high in early life (R)
chance of a female of that age giving birth to female offspring
Net Reprod­uctive Rate
the sum of the average number of female offspring produced by an average female in her life (Elxbx)
Gross Reprod­uctive Rate
sum of all offspring, the average number of offspring a female will produce in her life
Expone­ntial Population Growth
instan­taneous per capita growth rate. how many offspring an inidiv­idual produces per unit of time (intri­nsic)
net reprod­uction rate - average number of females a female produces over her life time. a multiplier based on generation time.
finite multip­lic­ation rate - used for non overla­pping genera­tions - not based on generation time - you can set the intervals
carrying capacity, maximum # of indivi­duals enviro­nment can sustain, population size where dN/dt = 0, n small = expone­ntial growth, n = k = no growth, n>k = population decreases
Density Dependant Growth


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