water (properties/importance)

(sea vs fresh water ions)

-becomes less dense as it gets colder than 4C (4 is densest)

-this is why ice floats

-water has a great capacity to dissolve substances (make them accessible to life)

-water separates compounds into ions

sea H20- Na, Cl, Mg, S04

 fresh H20 - Ca, HC03(bicarbonate), S04

alkaline - basic... greater than 7 oh pH scale

acidity is the concentration of H ions in solution

neutral = pH of 7 = 10^-7 moles of H⁺ per L

-pH of 0 = 1 mole of H per L

-most organisms have neutral blood pH

oxidation - used to harvest potential chemical eergy (give H or gain O)

reduction - red of carbon increases potential energy (gain H of give O)

assimilation - incorporation of energy of matter into tissues (such feeders are called autotrophs)

**energy assimilated during photosynthesis is chemically reducedfrom its low energy state in CO2 to high energy state in carbs

**oxygen is oxidized from its form in H2) to molecular oxygen... the energy stored in carbs is released by te oxidation of carbon to CO2 (respiration)

organisms and temperature

(upper/lower limits)

(thermal regulation by environment)

-radiation, conduction, convection, and evaporation determine the thermal environment of organisms (esp terrestrial habitats)

-high temperatures generally increase the rate o biological processes (factor of 2-4 for every 10C)

-upper temp limits occurs when proteins denature

-organisms in cold environments withstand freezing by metabolically maintaining elevanted body temp, or lowering freezing point of body fluids with glycerol or glycoproteins, or by supercooling their body fluids.

-availability of water depends on physical structure of soil

-more surface area of soil = more water it can hold (surface tension)

-sils of clay and silt therefore hold more water than coarse sands, through which drainage more quickly occurs

-H20 moves in direction of lower potential

FIELD CAPACITY - amount of H2O held against gravity

WILTING COEFFICIENT-  -15atm water potential of soil

-diffusion of H2O moecules ...

-solutes influence diffusion of H2O molecules (i.e. move from low to high concentration)

OSMOTIC POTENTIAL - expressed using pressure

-leaves generate water potential(sucking strength) when water evaporate from cell surfaces into atmosphere

stomates- point of CO2 entry and water escape

-plants avoid overheating by increasing surface area for heat dissipation

-plant nutrients from soil....N,P,K,Ca

-if nutrients are scarce, increase in root netword at expense of shoot

hyper-such as fresh water fish, which gain water from and lose solutes to surroundings

hypo-marine fish... gain solutes and lose water

-fresh water fish MUST retain solutes

-marine creatures MUST retain water

-solutions such as retaining urea i vloodstream (lowers osmosis)

-change osmotic potential of body fluids

water/salt balance in terrestrial organisms

-plants actively pump salts back into soil through roots

-animals use varied uring concentration to retain nutrients or get rid of

 H2O conservation 

-reduced activity, cool microclimates, seasonal migrations

-dry feces (kangaroo rat.. H20 reabsorption)

-feeds only at night

-an organism's ability to maintain constant internal conditions

-use negative feedback

 -requires tons of energy

-limits are protein denaturation and the ability to gather and metabolize quickly enough to generate heat

-homeothermy-constant temperature

poikilothermic - conform to external temperature

-in gilles, blood and water flow oppositely,

-water maintains progressibely greater oxygen concentration

-exists also in lungs of some terrestrial organisms

-exists in blood vessels as well to maintain heat in core if not in extremities

-area of earth that lies directly benearth sun's zenith

-reaches 23.5N on June 21(summer solstice) and 23.5S on Dec21 (winter solstice)

-hot air generally contains more moisture (if H2O is available)

-hadley cell is a cell of air circulation within atmosphere

-warm moist air rises at equator which results in abundant rainfall and air pushed N/S as evaporation continues/clouds empty and cool dry air decends at subtropical latitues.... creating desert conditions.... this in turn drived adjacent hadley cells up (to poles)

they exist at +/- 0to30,30to60,and polar

-where surface currents of air from hadley cells meet that have come from the subtropics(desert).. this is where they begin to rise again

**tropics are wet becasue water cycles more rapidly through tropical atmosphere, not because there is more water available

-rotation of the earth deflects direction of hadley cells

-flow shift TO west in tropics, as air moves away from equator and to east in mid-latitudes

TRADE WINDS- go to west in tropics

WESTERLIES- are the other ones (mid lat)

surface currents - caused by wind

-deep currents - variability in temperature and salinity cause differences in ocean density

upwelling- upward movement of ocean water

-occurs when surface waters diverge.. often rich areas of biological productivity as nutrients arise from depths.

-ITC follows solar equator!!! produces moving belt of rainfall

-equatorial areas typically have 2 rainy and 2 dry seasons (i.e. columbia)

-mid-latitude areas typically have a single rainy and single dry season

-outside tropics, temperature and rainfall vary between winter and summer..... influence of westerlies

Mediterranean Climate - winter rainfall/summer drought climate

Inverted Temperature Profile - in a lake, when coldest water lies at surface during winter... JUST BENEATH ICE

Spring Overturn

-deep vertical movements of water i lake in early spring caused by wind... bring nutrients from bottom to top and oxygen top to bottom

Thermocline

-zone of rapid temperature change at intermediate depth, as sun warms top of lake

-water does not mix across a well established thermocline

Stratification

-warmer and less dense water floats on cooler water

Fall Overturn

-surface water cools more rapidly than deep, and sinks to produce vertical mixing

Fall Bloom

-explosion in population of phytoplankton due to nutrient cycling of overturn... mostly shallow lakes

-epilimnion- upper layer of warm ater demarcated by thermocline

-primary production mostly occurs here

-hypolimnion - lower layer of warm water demarcated by thermocline

-typically, nutrients quickly depleted in epilimnion and oxygen quickly depleted in hypolimnion

-xeric - slopes that face the sun have this .... drought-resistant and shrubby

mesic - face from sun... cool and wet and moisture requiring vegetation

-decrease in temperature as elevation increases

-typically 6-10 degrees per km... due to expansin of air in lower pressures

-plants have difficulty trapping C02 without losing water.

-most plants employ C3 mode of C02 uptake, which is normally H20 efficient

-RuBP... rubisco(enzyme)... traps C02

-mesophyll cells loosely arranged to allow increased air flow

-RuBP has low affinity for C02

-used by plants in arid condtions (most grasses and corn)

-PEP-carboxylase has higher affinity for C02 that RuBP

-mechanism uses 4-carbon compound

-stomates closed and mesophyll tightly packed to reduce air circulation... keeps C02 levels in leaf low and conserves H2O

-photosynthesis can be highly efficient without water loss, but only occurs in bundle sheath

-these plants are even more efficient than C$ metabolism (desert plants and succulents)

-stomates open only at night when tranpiration is low

-OAA is formed and stored within vacuoles

-stomates close during the day and OAA is recycled to release C02 to calvin cycle

****day/night enzymes have different temperature optima

****limits- only can store so much (normal plants keep going all day)

-a tiny copepodthat lives in splash pools and experiences dramatic fluctuations in salt concentrations

-responds to these changes through rapid metabolic changes and blood solute concentrations

-produce amino acids to compensate (like urea in sharks).... this reduced osmosis/diffusion

-scarcity of water in desert makes evaporative cooling VERY costly

-desert plants orientate leaves away from sunlight.. others shed leaves and become dormant during hot/dry periods

-animals (kangaroo rat) reduce activity, go underground during day and be more active at night.... behavioral mechanism

-insects pump O2 to their body tissues using a tracheal system... the tracheal system opens to outside using spiracles

-trachea divide into tracheades which divide into finer air capillaries

-allows to be successful, but not big

-gas exchange and ion exchange occur across the gills in fishes and other aquatic animals

-without countercurrent mechanism, equilibrium of flow would be approached

-gill filaments maximize surface area

**-fish are more efficient in air, until gills dry out

-countercurrents also play a role in thermoregulation

-heat is shunted directly from artery to vein in the leg by passing the foot and allowing its temp to drop to conserve body heat

 -example of preserving heat in core at expense of extremities

Walter- biome classification based on climate zones... broke down vegetation types of the world into 9 categories

Whittaker- plotterd temperature and precip data for each biome... shifted triangle pattern

-used ordination (plotting lots of dots on scattergraph)

-plotted yearly averages

-he plotted yearl

-TROPICAL RAINFOREST- has very little transpiration pull.. however trees are heated more than surrounding clouds

- even though air is 100% saturation, leaves can stilll transpire

-blue always above orange, orange always above zero

TROPICAL SEASONAL FOREST- orange above blue in dry season, orange always above zero

SUBTROPICAL DESERT

-orange always above blue, orange always above zero... this is bottom left corner on whittaker plot

TEMPERATE RAINFOREST-

-blue way over orange, orange sometimes hits zero, but does not go below

-mountains trap moisture coming off ocean

-requires specific topography

-not a widespread biome... world's biggest trees

TEMPERATE SEASONAL

-orange drops below zero in winter

-plants mut be adapted to winter

-average precip and temp in world

-mostly in North Hemisphere... east coast NA

-blue always above orange

TEMPERATE GRASSLAND DESERT

-blue dips below orange for about 4 months (Jul-Oct)

-orange drops below zero

-grasses mostly (can go dormant, use C4 mechanism)

-if blue below orange for extended time, riske of fire increases

-many plants benefit from fire... nutritious ash, germinating with flame... some tolerate burning while other species die

-grass is burnt above ground, but below ground survives

BOREAL FOREST

-circumpolar band... low biodiversity grows until "free line"

-orange crosses zero for man months... summer is spent melting

-blue always over orange

'

TUNDRA

-mean annual temp is below zero

-lots of permafrost.. plants can't sink roots into this

-fairly wet area, doesn't drain well

-blue always over orange

littoral/limnetic/benthic

-

-littoral zone- zone in lake where light reaches bottom..  rooted plants can grow here

limnetic zone - where light does not reach bottom... primary producers are phytoplankton (suspended)

benthic zone - environment depends on amount of oxygen

-no primary productivity

-muddy substrate

-reversible response

-shift in physiological tolerances using enzymes

0shift in morphology... skin pigments

-KNOW FIG 9.9 (goldfish)

-non-reversible... persistent environmental variation

-i.e - shading a plant will grow yeoolow but very fast ... puts all resources into trying to get back into sun

plants, seeds, insects, vertebrates

aestivation (avoid heat/drought)

hibernation (vertebrates avoid cold)

diapause (very little energy insects)

-individuals A and B ahve different response to same environment

-can change to be like other individual when introduced to their environment

-are patterns of maturity, fecundity, and parity (vary across time/space/species)

-pioneering work in this field by David Lack (clutch size and latitude)

**a life history is a set of rules and choices influencing survival and reproduction

-environmental variation occurs across space and time and on small/medium/large scales

-humans have modern responses to variation

-organisms are adapted to 1)environments and 2)environmental variation

NATURAL SELECTION REQUIRES

1)variation between individuals

2)heritibility of this variation

3)selection pressures

life history patterns related to:

-physical environment

-biotic environment

-other life history factors

1)SURVIVAL VS SURVIVAL

-starvation vs depredation

2)REPRODUCTION VS REPRODUCTION

-most obvious = tradefoff b/w seed size and seed quantity

-corresponds to fast/slow lifestyle tradeoff

3)SURVIVAL VS REPRODUCTION

-allocate resources to self or reproduction?

-if lots of predators, reproduce relatively early is best

-if you expect long lifestyle, reproduce later

-one reproductive bout (annual plants/ may flies/ salmon)

-iteroparous - more than one (perennials, most animals)

-non equal gametes (males small, females large)

-allocation of resources... selection for what works best

dioecious- individuals that produce only one sexual form (2 houses)

monoecious- one house... flowers... male function first then female function .... or ... at same time male and female,,, or ... male/female flowers on same individual

** many adaptations exist in plants to avoid inbreeding

-being rarity has an advantage (competition for you)

-better to be rare... get to contribute more genes..

Biased Sex Ratio-if female in good condition but male not... can skew bias towards getting a female... if male in good condition but not female.. female can skew in favor of getting a male

males- # of mates, # of fertilizations, avoiding cuckoldry

females - male genetic quality, male resource quality

promiscuity- no post gametic investment ... chance determines which gametes meet

-success based on gamete #

-i.e. wind pollination... no longterm bonds

polygyny-male mates with many females vs parental investment

-males compete, for mate access, territories, resources)