study responses at different levels of biological organization

study responses over different time frames

make generalizations across different groups to determine common mechanisms

Their sweat has anti-microbial properties,

acts as a sunscreen,

and prevents dehydreation

Desribe "hippo sweat" at

tissue level

cell level

molecular level

tissue level: lacks sweat glands

cell level: synthesis and secrtion of it

molecular level: hipposudoric acid and norhipposudoric acid

occurs at multiple levels of organization.

ex- llama at high altitudes develope high hemoglobin concentrations which aids in process of oxygen extraction.

drop temp a bit for long period of time

ie hybernation in bears

measure global gene expression in warm and cold acclimated fish using gene array technology.

isolate RNA from cold and warm acclimated fish and label with different dyes.

hybridize labeled mRNAs and llok at the reative abundance of genes

the expression of each cDNA= ratio of transcript abundance in each cooled sample realtive to its mean abundance in the control warm-acclimated samples.

generally maintain constant body temp

regulate body temp within narrow physiological range

body temp fluctuates

reulate body temp by expending metabloic energy or using active mechanisms

(birds and mammals)

depend on external sources of heat to maintain their body temp

everything other than birds and mammals

regulate body temp at constant level some times, but other times not

hibernating mammals

small mammals and birds

tuna and related billfishes

in regard to enotherm and ecotherms:

when environmental temperature increases, body temp will:

for enotherms will remain constant

for ectohterms will euqilibrate to environmental temp

In regards to endotherms and ecotherms,

as environmental temp lowers, metabolic rates:

in endotherms, increases ( up to 10 times that of ectotherm)

in ectotherm: it lowers (1/10 that of endotherms)

sustain logner periods of intense activity

evolve highly efficient specialized enzymes

can thrive in diverse environments

require more energy

spend more time foraging which leaves less time for growth and reporduction

high metabloic rate= high respirotaty rate and higher evaporative water loss

spend little energy on thermal regulation

invest more engry into growth and reproduction

requires less food

spen liess tiem foragin, more time avoiding predators

require less water

be small

dependant on the environment for warmth

limited range of suitable environments

lower metabolic rate- limits duratino of burst activity

die

hibernate

torpor

metabolic depression

= metabolic + (heat gained-heat lost)

= metabolic heat + heat transferred

heat generated at standard metabloic rate

heat from activity

in regards to body temperature

low surface area: volume ratio =

in regrads to body temp

high surface area: volume ratio

contraction of anatagonistic muscles

hydrolysis of ATP generates heat

legs of northern birds and mammals, slippers aof marine mammals

blood vescles restrict amount of heat going to feet and capture it back

mRNA synthesis

Protein synthesis

fuel use

O_{2 consumed}

ATP turonover down to 5% of normal

Q₁₀= Rate (T)

             Rate (T-10)

migrate to warmer microclimates

spend witner in simple stage-eggs, in cysts

heat up house

freeze avoidance

freeze tolerance

making antifreeze (protiens) to bind tto micrposcpic ice crystals

make cryprotedctants which lower freezing point

will freeze and not die

promte ice crystal formation outsdie of cells (leads to dehydration of cells and hypoxis becuase oxygen is no longer deliverd to cells)

produce ice nucleating proteins

add ice nucleating protiens to blood

alter metablosim to synthesize cryoprtectants

avoid ceullular dehydration with cryoprotectants

evaporating via the lungs, to mouth to nose

sweating

exretion via the urine and feces

modify kidney to reasborb water and make a concentrated urine

internalize lungs to prevent water loss

untilze a counter-current mechanism to retain respiratory water vapour

reduce the permeability of skin to water

from adrenal gland

reabsorbes sodium back into blood

from pituitary

reabsorption of water into blood

act by inhibiting ADH secretion

reduced reuptake of water into blood

increase urine

high

high

dry environmetns

heavy cutile to limit evaporative loss

succulent gorm to store water

regulated opening of stomata

deep tap/fibrous roots

exclude salt uptake

exrete salt--salt glands in leavse

put salt in vacuoles

succulents--take on extra water

constant darkness

selcetivly destry SCN with drugs or elcetirc shock