Lesson six Flashcards
Is temperature a big deal?
yes and no, usually warm temperatures do not affect organisms however they affect abiotic factors, like water less causing drought or dehydration
What are water relations?
This is the way that organisms maintain internal concentrations, organisms must balance water losses to environment with water intake. this water balance is called water relations =
How do concentration gradients influence the movement of water between an organism and their environment?
Areas of high concentration to low concentration (water has tendency to move down concentration gradients). Organisms will loose or gain water from the environment
what does aridity mean?
the lack or moisture, so dry
what does salinity reflect?
the relative aridity of aquatic environments, (on land its dry, dessert extreme aridity, when you go to water it changes to salinity which is salt concentration)
Why is water availability different in colder regions?
Colder regions much of their water is frozen for six months or more which means they have a short growing period
What is waters potential?
waters potential energy or its ability to do work. It is kinetic energy and also potential energy due to gravity
what is evapotranspiration
Moves water to the soil to the roots or atmosphere
what is Ψ?
this is a symbol that denotes pressure units
What is Ψ0
references water potential (no salt concentrations, pure water)
What iis Ψgravity
force of gravity acting over a unit of area
what is Ψsolute?
osmotic pressure (salt) seen within the fluid. it is driven by differences in water concentration. Wate without solutes will have the most osmotic pressure
what is Ψhumidity?
water vapour pressure salutinity
what is Ψmatric
matric pressure, caused by contact with surfaces
what is Ψprssure?
sum of extraneous pressure imposed on system (weight of the water etc)
why do favourable chemical reactions decrease potential energy?
Because there is less energy being used to go from areas of high potential to low potential (soil water must have higher potential than the trees xylem, the trees xylem must have higher water potential than the leaves, the leaves must have a higher water)
What is diffusion?
Solute movement is called diffusion, this goes from high to low. In aquatic animals they have a solution (salts, blood, etc) inside them as well as outside them. this is divided by a selectively permeable membrane. It is the salt molecule that travels here (SOLVENT MOVES)
What is osmosis?
movement of water across a semipermeable membrane. Water moves down its concentration gradients. This is the transportation of water not salt. The less solute the solution has the higher osmotic pressure it has. (SOLUTION MOVES)
What is Isosmotic?
organism body water/solutes equal the external environment. They are are equilibrium
What is Isotonic?
This emphasizes the solute concentration of the external environment.
What is hyperosmotic?
organism body water concentrations are lower than salt. As water comes in lots of solute comes out
What is hypotonic?
Relative to organism, higher water concentration inside compared to the salt.
What is vapour pressure?
related to the quantity of water in the air
what is matrix?
a surrounding medium or structure
what is a meniscus?
this is the shape that water takes when poured into something, how it gets like oval shape and isnt a real line
What does the strength of matric depend on?
depends on distances between particles, as the distance increases matric pressure decreases
What is evapotranspiration
water molecules adhere to each other. as one molecule leaves a leaf by evapotranspiration it tugs on neighboring molecules pulling them closer to the pores
How do terrestrial plants and animals regulate internal water?
They balance their acquisition against water loss, They face two water related challenges, potentially massive losses of water to the environment and reduced access to replace water
Water acquisition from animals?
They absorb water from the air, but most feed or drink to take in water. This is called metabolic water
What is metabolic water?
water released during cellular respiration
What is water proofing good for?
It is a way to reduce water loss, this minimalizes water loss
how else can animals conserve water?
producing concentrated urine/feces with low water content, condensing and reclaiming water vapour in breath, restricting activity to times and places that decrease water loss
What is water use efficiency?
biomass of plant tissue per gram of water used, WUE depends partly on leaf area relative to its roots area or length
How can plants conserve water?
Small leaf area, roots rationing, reduce leaf area often dropping leaves, thick leaves, with less transpiration, dormant during ties when moisture is unavailable
What are anadromous fish?
They hatch and spend t=some of their juvenile developmental stages in freshwater, then they migrate to the ocean spend most of their life there and then return to freshwater to spawn
Catadromous Fish?
They spawn in saltwater, then spend most of their time in fresh water
