Biology 1070 Exam Notes

Inquiry Case #1

Dioecous: Most species are separate male and female

Principles of Natural Selection – OVHD:- Over production of offspring- Variation of traits among offspring- Heritability of variation- Differential survival of offspring

Organization: Da King Phillip Came Over For Good Sex- Domain – Kingdom – Phylum – Classes – Orders – Families – Genus – Species

Ontogeny: Specific changes in morphology from youth to old age

Cryptic Variation:- Variation must be heritable – genetic basis for observed trait- Morphological variability can also be due to environmental differences

o Same genotype - different phenotypes (phenotypic plasticity)- Minor phenotypic differences but a lot of genetic variation

Disparity: How physically different species are from one another

Phylogenetic: Particular way in which living things are related to one another

- Sister Taxa – Closest descending from single recent ancestor - Internal nodes – extinct ancestors- Topology – order of the branching trees- Clade – lineage (evolutionary groups worth naming)

o When descendent is left out, it is paraphyletic

Convergent Evolution: When features have evolved more than once in independent lineages as a similar adaption

- Homology: Two species with similar traits that are closer relatives have inherited characteristics from a common ancestor – monophyletic

- Homoplasy: Two species that are not closely related, but have a similar trait that evolved separately.

Biological Variation:- Genetic variation: differences at DNA level among individuals within species- Alleles: different versions of the same gene- Errors in DNA replication (random) – leads to mutation, primary source

- Genetic variation can change within a population as a result of:o Mutationo Natural Selectiono Genetic Drift – random changes in allele frequency in population

Sampling error – randomly choosing part of population and grab more of one species

Fixation – loss of one allele, so only one is left Bottlenecks: Sudden population reduction (random, bad

luck – natural disaster) Founder effects: Alleles found in mainland population is

different than founders – new frequency/populationo Gene flow – sharing of alleles among populations

- Causes of Erroro Point mutation – base pair substitution in sequence create new alleles

Chromosome mutation – rearrangement of fusing chromosome segments (alter gene order) – breaks in DNA caused by radiation or other factors

o Gene duplicates – duplication of a short stretch of DNA, creating an additional copy – unequal crossing during meiosis

o Genome duplication (polyploidy) – addition of a complete set of chromosomes, creates new species

Adaption: A characteristic that enhances survival or reproduction of organisms that have it, ancestral – evolved through natural selection

- Frequency: proportional representation of phenotype of a genotype- Species born with traits that will randomly allow them to survive better- Adaption is not forward looking – can’t product something for the future- Natural selection requires heritable variation among individuals - Co-option – a feature that serves one function and takes on another

Species: inter-breeding natural populations that are reproductively isolated- Doesn’t apply to asexual organisms, or hybrid animals- Gene flow: movement of genes from one population to another (causes two

populations to become more similar) genetic isolationo The flip side of gene flow is new species (genetically isolated barriers)o Properties that block gene flow

Geographical barrier Properties within the organism itself Ecological specializations: eating different foods, nocturnal vs

dinural, living in different parts of the lake, etc.o Allopatric: Other place, geographic separationo Peripatric: Same geo-isolate, some manage to survive and reproduceo Parapatric: Animals beside each other, chose not to breedo Sympatric: Genetic divergence of one species, in same area

Hypothesis: Stating a proposed relationship between a couple different variablesInquiry Case #2

Biodiversity: Different scales of variation (genetic, species, ecosystem)

Ecosystem: System formed by interaction of organism community w/ environment- Made up of communities and abiotic factors- Community: collection of species living in a given area- Diversity characterization

o Within a Habitat: Alpha Diversity: within one habitat (high alpha – low beta) Evenness: SDI = [(nspecies1/nall species) x ln (nspecies1/nall species) +]

o Across Habitats: Beta Diversity: β = (S1 – c) + (S2 – c)– species – common Gamma Diversity: Total number of species across all habitat

- Global diversity is the net outcome of opposing processeso Diversification: Through speciationo Loss of Diversity: Through extinction

Allopatric speciation – different place Sympatric speciation – same place

- Habitat: Environment in which a species is known to occur- Ecosystem engineering – some organisms can control resource availability- Intermediate Disturbance Hypothesis: Highest species richness will occur at

intermediate level of intensity of frequency of natural disturbance.

Extinction and Extirpation: Once a species form boundaries, they are permanent- Endangered: one whose abundance has dwindled, may be lost- Extirpation: Individuals will exist, but no longer in other common areas- Extinct: Ones that are gone from earth

o Species persist for about 4 million years (25% go extinct every year) Failure to adapt to changing environment Failure to keep up with evolution of a competitor Being driven to extinction by a new

competitor/pathogen/predator Losing an essential host, prey or partner species

o Mass extinction KT – 65 million years ago 50% of species lost rapidly (10s to 100s of thousands of years) Major events in the last 500 million years include great dying

(loss of 95%, opened niches for mammals instead of dinosaurs) 100 million years for biodiversity to recover, spike in

diversification afterwards Holocene extinction – caused by human society

Species Composition:

- Dependent on global, regional and local scale - Biodiversity decreases with latitude, and population increases with latitude

Species Richness: Number of species present in a defined area (saturated when leveled off)

Species Abundance: How common a species is in a defined area (frequency)

Abiotic and Biotic Factors:- Abiotic: Physical and chemical feature of an environment (light, water, temp)- Biotic: Living things that shape an ecosystem (decomposers) - Determine limiting factors by observations, correlations and experiments

o Experiments: Transplant in range (control)/out of range (treatment)

Population: Population2 = population1 + Birth – death + immigration – emigration- Density dependent regulation

o Factors that affect population based on size- Density independent regulation

o Factors that can intensify the effects of density dependent factors- GRAPH: Survival vs. Abiotic factors (optimum has highest peak)

Carrying Capacity: Ability of an environment to sustain a population- Affected by biotic (predators) and abiotic (nutrients) factors

Fundamental Niche: Possible dimensions in which a species can surviveRealized Niche: Dimensions in which species can actually live after biotic factorsEcological Niche: When species overlap

- Competitive Exclusion: One of the species disappears from area (separate)- Character Displacement: Species co-exist, occupy different niches (overlap)- Co-existence: Species continue to live in area, but lover numbers (lower CC)- Patterns of Distribution:

o Clumped – common, offspring can’t move (around resources)o Even – Competition for resources and spaceo Random – Rare, no species interactions

- Species can be obligate (must live with partner) or facultative (no partner)

Edge Effects: Gap between area being built up and woodlot- Edge become hotter and drier- Resources are spatially separated, edge has access to both- Mutualism: Both species benefit- Competition: Species have a negative effect on one another- Predation: One species is benefited, the other has a negative effect- Commensalism: Species 1 is benefited, other not harmed- Neutralism: They don’t effect one another

Biotic Homogenization: Replacement of local biogas with non-native species that can coexist with humans

Biome: A large naturally occurring community of flora and fauna occupying a major

Inquiry Case #3

Climate Change and the Arctic: - CO2 in the ecosystem makes the temperature rise significantly because of

burning fossil fuels – artic is especially effected- Sub-arctic: Variety of aquatic and terrestrial ecosystems (characterized by

biotic and abiotic factors) - High-arctic: Dominated by tundra, freshwater and marine habitats- Arctic animals: Marine - constant body temperature of 37˚C – thick blubber

o Aquatic: Narwhal, Bow head whale, polar bear, Atlantic puffin, arctic char, Greenland cod

o Terrestrial: Musk Ox, caribou, arctic fox, arctic ground squirrel, wooly caterpillar, rock ptarmigan

o Endotherms: Inside heat (warm blooded) animals –mammals & birdso Ectotherms: Do not regulate body temperature internally, same as

surroundingso Some stay active during winter, find scarce food and maintain internal

body temp, others hibernate and drop temp to just above freezingo Some ecothermic animals can’t avoid freezing and survive freeze-

thaw cycles over many years o Terrestrial ecotherms (amphibians, reptiles) have very low metabolic

rate – same temp. as environment. - Arctic plants:

o Face a short growing seasono Vascular plants tend to be small and freeze tolerant o Plants that lack roots and do not need soil will prosper (Lichen)

Algal – convert solar energy and CO2 into carbs Fungal – require food source, use carbs for fuel

Levels of Organization- Populations: Climate change may affect survival, growth and reproduction - Communities: Changes in species distribution or frequency- Ecosystems: Influence nutrient cycling between abiotic and biotic factors- Molecule: Motion of a molecule, high temp increases motion, low slows it- Macromolecules: Sensitive to temperature change (enzymes – optima range) - Cells: Temp changes cause a stress response – may die

o Chaperones – involving in protein folding, HSPs help restore native structure of a protein that has been damaged by heat stress

- Organ systems: Temp changes more complexo Eg. Arctic Char (ecotherms): An increase in water temp, increase

blood pumped/min – causes changes on the organ system- Whole organism:

o Eg. Caribou – would be too warm after running, pant to reduce body heat (lost from saliva to environment), once at 37˚C – stops

- Homeostasis: Maintenance of internal environment (not only temp)

Ecological Interactions: Arctic animals can adapt to cope with severe conditions- Have specialized adaptions, and if temperature warms, then it will impact

adapted animals, and interactions will change

- Arctic is warming faster than other areas in earth – in response to man made activity – may be 8˚C warmer by 2100 – diminished ice cover = catastrophe

- Key abiotic factors – sunlight, plants, temp fluctuation, ice- Effects on habitats – no sea ice = no food hibernation- How does polar bear’s prey/diet change – look at organisms and distribution

Physiology: The study of organism’s structure and function, including homeostasis and encompassing cells, tissues, organs and body systems

- Physiological adaptions are not the same as evolutionary biology

Time Scale Interactions: - Acute: Immediate response (cold temps and shivering)

o Lasts a short time (mins – hours)o Normal: daily fluctuations in temperature (extreme – hottest day)o Bio-response: Behavioral adjustments (sit in water) or physiological

(sweat or death)- Chronic Acclimatization: Change in physiology to adjust set points in relation

to prolonged change in environment o Few days, weeks, yearso Normal: seasonal fluctuations in temp (extreme – hottest season)o Bio-response: Migration, acclimatization, extinctiono Example of chronic stimulus: multiple long exposure – cold

baths/moving somewhere cold

- Evolutionary Adaption: Occurs at multiple levels of organization, over generations – result of natural selection – multi-generational

o Normal: gradual climate change (extreme – rapid climate change)o Bio-response: Habitat tracking, adaption, extinctiono Examples – staying somewhere cold, passing on adaption

- Arctic plants and animals have lived in arctic ecosystem for years, and must cope with temperature change in the three time scales

- Example: How would an Arctic Fox cs. Char response to an increase in 5˚C in temp if it were acute, chronic, and generational?

o Need to know: Temp range they are normally living Physiology of animals and how they respond maintain

homeostasis in the body Endotherm/ecotherm Multi-cellular/uni-cellular Is the animal available to avoid the temp change? Behavioral response can invoke to reduce the impact of the

temp – panting What times of physiological responses are possible and at what

cell level – cells, tissues, organso Acute Response:

Fox (20-25˚C) - regulate body temp – shade, or panting Is able to remain active even when temp falls below -50,

o Small ears, short muzzle, short legs, and small body limit heat less

Char (4-9˚C) – body temp increases to 9˚C – has to deal with the factor that the body temp has risen, cannot change

Acclimatization: Response in the wild induced by natural climatic changes- Example: Polar bears

o Actually have dark skin, but white furo They could be white to blend in with snow for preyo Thick fur, lots of blubbero Large size, low surface area to allow less heat losso Hollow hairs, can get froth of algae in warmer temps. o Only lose heat in eyes, mouth – retain heat

- Population adjustment is adaption, acclimatization is the individual

Acclimation: Response in the lab induced by experimental changes- Example: Fish: Measuring how fast they can swim in different water

o Cold fish swim best in cold watero There is a steeper drop for those who are acclimatized to warmer

water and forced to swim in colder watero They both swim the same at 15˚C

Arctic Challenges- Most animals require O2 for metabolism and release CO2

- They need different nutrients (protein, carbs, fats)- Waste: Fluid and solid wastes from digestion and metabolism are released

and must balance internal ions- In cells: exchange occurs across membranes

Homeostasis: Animals maintain relatively constant internal conditions in a fluctuating external environment

- Ectotherms regulate everything but temperature- Uses a regulatory system – NEGATIVE FEEDBACK- Hibernating endotherms do not lose complete control do not lose complete

control, they have a lower set temperature – still regulate through internal metabolic processes

- Molecular and macromolecular level:o High temperatures increase molecular movement and can even

denature proteinso LDHs from cold acclimatized ectotherms have a looser structure that

are able to bind the substrate more easily in the cold. They can change the amount of LDH present

- Cell membrane: Ecotherms change composition of membranes to maintain fluidity (using cholesterol and altering lipid composition)

o Warming – more fluid, cold – less fluidity- Circadian Rhythms

o Most living organisms exposed to light and dark rhythmo Controlled by internal clock

Structure and Function:- Example: penguin can stand on ice bare foot for long time, but a human can’t

o Penguin waddles and wear a skirt of belly fat to knees – covers most muscles and keeps them warm (adaption)

o Veins and arteries structured with “concurrent heat exchange system”o Found in ears nose and extremities of bodyo As warm blood in artery goes towards the capillary bed, veins are

wrapped around and the hear of the heats heats them - Problem: Vascularized limbs are major sites of heat loss

o Arteries give up their heat to the veins as they travel

Regional heterotherms – flukes & flippers of whales, seals and walruses- Within one organism we have different body parts at different temps- Changes at cellular and molecular level

o Membrane phospholipids – unsaturated has at least one double bonds, saturated is totally straight

o Unsaturated takes up more room, makes it more fluido In colder environments need to increase fluidity w/ unsaturatedo Deep living organism – difficultly maintain homeostasis

Biotic Interactions in Warmer climates:- Polar bear currently only large, land-dwelling predator in arctic region- This could change as rangers and other predators expand or shift - Polar bears move south or others up, and create new competition- Which info is most important when predicting which bear species will

expand into the arctic under climate change? Whichever is closestBrown Bears and Polar Bears

- Brown and polar bear are sister taxa – closest living relatives - Possibly that brown bears are not a clade – what does this mean?

o Polar bears could have evolved from brown bears o Mitochondria – inherited maternally and has its own DNAo Interbreeding is possibleo Nuclear DNA: Not maternally inherited – polar bears and brown bears

are very distinct lineages o Mitochondrial DNA – possibly of similar lineage

Body Size and Surface Area:- Exchange with environment influenced by body size and surface area- Larger the animal, greater its requirements for nutrients and gases (absolute

requirements) – goes up with body size- Bigger body size means lower surface area to volume ratio, means less

efficient energy exchange

Metabolic Rate and Temperature: - Indication of how much energy of O2 is being consumed per unit time- Measured in a respirator (ectotherms or endotherms)- Q10 = (Rate at Temp)/Rate at temp-10) –also measured in O2 consumption- Q10 usually around three, except when animals go into hibernation (small

decreases = bigger decrease in metabolic rate)

Hibernation:- Once ambient temp falls, there is a larger gradient between internal and

external temp greater heat loss- To thermoregulate, large mammals in arctic need a lot of food or fat stores- Animals can also hibernate to reduce metabolic rate and body temp – doesn’t

need as much energy - Hibernation usually lasts several weeks or even months – shorter period is

called torpor (hummingbirds – nightly) - Small arctic mammals hibernate while larger ones stay active – why?

o Metabolic rate per kilogram is higher in a small animals, and small mammals need more energy for each cell

o Smaller mammals lose heat faster – need more energy- Most hibernating mammals leave den at a lower body mass because of

diminished fat stores – some store food and eat periodically

- Whether they arouse periodically or just once at the end of winter, hibernation requires a great deal of energy – done using brown fat

o High density of mitochondria – normally synthesize ATPo Brown fat mitochondria contain protein called termogenin – enables

cells to generate 10x more heat o Brown fat used to generate body heat is called non-shivering

thermogenesis - Animals that hibernate use white fat normally as their major fuel

Active Overwintering Small Mammals: - Penguins can reduce their surface area exposed to cold by huddling- Energy savings are approximately 50%- Without this – would have to double fat stores, huddling is an adaptive trait

Time Scales and Organization:- The more microscopic the level, the faster the time scale - The emergent function is the result of different things at different levels of

organization and time scales- Levels of organization example: Emperor Penguin

o Population – huddling to keep warm (rotating inside and outside) o Organism – Really fat (more fat they have, more warm they will be)

Bodies will be very large, and bills small (less heat escaping) – rock back and forth on feed

o Organ system concurrent heat exchange Acute Chronic Evolutionary

Molecular Release of glucagon increases breakdown of fatty acids

Adaptions in haemaglobin related to cold and diving

Cellular/tissue Counter current exchange regulation

Decrease metabolism

More fat and feathers than other penguins

Organism Roll back on heels, tuck in flippers

Preening to maintain feather insulation

Large bodies with small appendages

Population Huddle together Breeding season in large colonies

- Why is there no information on molecular acute and population evolutionary – there are more behavioral at the different time changes, or nothing studied

Woolly Mammoth:- Extinct – had many adaptions (thick fur, blubber) - Create mammoth hemoglobin from DNA (functional protein) and test in cold

conditions compared to polar bear

Freeze avoidance- Use strategies to avoid freezing even at subzero temperatures- Species that use this strategy are freeze intolerant- Promote conditions where cellular water can be cooled to below zero before

ice crystal formation occurs- Super cooling – bringing the body temp down slightly below zero to avoid

tissue damage (intolerant) o Making anti-freeze (binds microscopic ice crystals)o Make glycerol, sugars and proteins - lower freezing point

- Behavioral avoidance: birds migrating (freeze intolerant)- Production of antifreeze compounds: (freeze intolerant)- Ice crystals are seen to puncture innards of animals – antifreeze stops this- Winter flounder

o Body fluid freezes between -0.6 and -1.1o Sea water freezes at -1.9 – why doesn’t the fish freeze (antifreeze)

o The higher the anti-freeze concentration, lower the plasma freezing point

o In the winter months, when the water is freezing, the anti-freeze protein production increases

o Chronic: acclimatization is another factor to take into account – slow response (takes a couple months)

o Observation: Anti-freeze proteins increase in the fall and decrease in the spring – what are the possible triggers?

Drop in temp, ice-crystals forming, internal clock, lack of foodo Prediction: If temp is the trigger, then a decrease in temp will initiate

an increase in concentration of anti-freeze proteins Experiment: control group (20 fish, 10 degrees) +

experimental group (20 fish, -1.5 degrees) and measure plasma Seen that temp is the same – next try light (determined that

anti-freeze increase with decrease time in light - Insects:

o Void digestive tracts to remove small particles (ice nucleating agents)o Also produce glycerol and other sugars – lower freezing point and

allow body fluids to remain unfrozen

Freeze tolerance - Strategies to promote controlled freezing to minimize tissue damage- Species that use this strategy are freeze-tolerant- Species actually freezes, then thaws to live again- Synthesize of ice nucleating agents – there to promote the formation of ice

crystals (tolerant)- Super cooling – bringing the body temp down slightly below zero to avoid

tissue damage (intolerant) - WOOD FROGS – HOMEWORK: Find a place to hide free of predators for the

winter – accumulate glycerol/glucose as they start to freeze to prevent cytosol from freezing and limiting osmotic imbalance

o Wait to make anti-freeze until ice forms – adrenaline starts its production

o Glycogen turns into glucose – spreads throughout the body through the blue

o Glucose acts as an osmolyte and antifreeze, lowering tissue freezing point, also inhibits metabolic processes – helps limit energy required by the cells in this frozen state

o Lets organs freeze in extracellular spaces – freeze solid with glucose as cryoprotectant – protects organs – they dehydrate

o They don’t just freeze solid – they control what freezes o Makes use of ice nucleating agent to trigger ice formation on the

outside of cells/organs

Osmosis: Passive movement of water across a membrane from low concentration to high concentration of solute

- Hypertonic – solutions causes cells to shrink (water leaves cell)- Isotonic – normal cells- Hypotonic – solution causes cells to swell (water enters cell)- Ice crystals from in the extracellular fluid – they reduce the amount of free

water outside the cell – creates an increase in osmotic pressure- INSERT QUESTION - The formation of ice crystals inside the cells cause physical damage to cell

membranes and structure

To freeze or not to freeze? Freeze Tolerant

organismsFreeze Intolerant

OrganismsIce Formation Yes NoOrganisms produce antifreeze proteins

AFPs inhibit additional ice formation

AFPs stabilize a supercooled state

Organism produces glycerol and or sugars (cryoprotectants)

Cryoportectants stabilize cells to prevent osmotic

damage when

Cryoprotectants increase supercooling

capacity (lower freezing point)

extracellular fluids freeze

Ice-nucleating agents (proteins, salt crystals, bacteria)

INA’s initiate ice formation outside of

cell

INAs not used – prevent ice formation

Clicker Question: Acclimatization: Arctic fox

a) Arctic fox breathe more times per min in the summer than winter because they are actively hunting prey – Not an axisb) As O2 consumption increases, the temperature decreases in both summer and winter animals – winter fox acclimatize to colder ambient temperature - Noc) Arctic fox acclimatized to summer conditions begin to increase oxygen consumption at a higher temperature than foxes acclimatized to

winter condition – may related to the differences in the insulating properties of their fur in different seasons - possibled) Arctic fox acclimatized to summer conditions have a higher tolerance to changes in ambient temperatures than foxes acclimatized to winter conditions. This may related to the physiological processes or structures that change to provide more optimal function in each season – graph doesn’t talk about tolerancee) Arctic fox acclimatized to summer conditions begin to increase O2 consumption when ambient temperature is around 10˚C, whereas fox acclimatized to winder conditions do not begin to increase consumption until temperatures are -15˚C. This different probably related to the countercurrent exchange system in the periphery. – only talking about one fox, no

Regulators and Conformers

Conformers: Allow internal environments to follow external changesRegulators: Maintain constant internal environment in the face of carrying environmental conditions (straight graph line) – working against the environment

Body Temperature Regulation- Too Hot: Need to stay cool

o Offload heat, produce less heat, find cooler temp Dilation, evaporation, metabolic depression, dig in the dirt and

lay in it, sit in the shade aestivation- Too Cold: Need to stay warm

o Produce more heat, lose less heat, need less heat Shiver, non-shivering thermogenesis, digestion, other muscle

activity, constrict, metabolic depression, hereothermy, torpor, hibernation

Torpor and Hibernation in Endotherms- A very short period of time hibernating - Small endotherms with high metabolism, short periods (overnight) –

requires minimal food stores, rapid body temp drop, decreased metabolic rate, reheat by shivering or brown fat

- Hibernation requires large food store, long periods, slower body temp drop, decreased metabolic rate, non-shivering thermogen and shivering thermogen

- During hibernation – ground squirrel body temperature periodically returns to normal, even though soil remperature remains low – non-shivering thermogenesis causes periodic rise in body temperature.

- During hibernation – all physiological processes decrease as oxygen uptake increase – they all level out

Brown Fat vs. White Fat- Our bodies have more brown fat when we are babies, and almost non when

we are older- White fat – a cell that is fully composed of fat – used in shivering

thermogenesis - Brown fat – dark – lots of mitochondria, little droplets of fat dispersed in it –

non-shivering thermogenesis – produces energy directly to the body because of energy reserves – allows transfer of energy

Why are there no large deep hibernators? - Large body size retains heat, does not reach low enough level --? Decline of

temperature is lower than that of a smaller animal. Not necessarily the case – some large ones can too

- Not capable of generating sufficient heat to raise temperature of large body mass upon arousal

- Low heart rate during deep hibernation would not be sufficient to maintain blood flow to all parts if large body

- What do black bears do?- Reduce MR, not deep hibernators

- Fat water, no food or water coming in - Energy/water that it needs is coming from its body- One of the byproducts of burning fat is water (metabolic water attained

though this process – only happens in bear when its body is repressed) - Human Hearts vs. Bear Hearts

o Human: Lower HR, blood pools in the heart to increase pressure, heart muscle stretches and weakens

o Bear: lower HR, change in myosin structure in heart muscle, stiffens heart (reversible) maintains heart function

- Brown Bear vs. Polar Bearo Which variable is most important – DIET? Polar bear doesn’t evolveo Polar bear head is different – adaptive to heating meet and fat,

elongated snout, canine teeth – carnivoreo Brown bears are omnivores – can eat everything

Tips:- Reading Graphs:

o Identify the type of grapho Read the title and or captiono Read the aces (labels? Units? Scale?) – consult legendo Interpret the pattern (correlation? Differences among groups?

Statistics? Error bars? P-value?)o Evaluate the reliability of the graph and the authors interpretations

(anything misleading? Valid conclusions?)

Homework:1) Read Article, summarize and graph:

2) Fill in Table for Polar bearAcute Chronic Evolutionary

Molecular

Cellular/tissue

Organism

Population

3) Are there any freeze tolerant endotherms?

4) Do all endotherms attempt to regulate a constant high body temp at all times in the cold?

5) Why is it that humans can’t freeze and bounce back? What are we lacking? Why can’t we hibernate?

6) How do endotherms deal with extreme cold? Does it depend on timescale of exposure? How?

7) What kinds of animals are conformers? What kinds are regulators? Can animals be both? Plants?

8) Practice Skills finding and interpreting scientific information: a. How do food frogs (Lithobates sylvaticus) survive the winter?

i. Molecular/tissue/organism scale adaptions?

ii. Acute/chronic/evolutionary timescale?

b. How do winter flounder (pleuronectes americanus) survive in sub zero seawater?

i. Molecular/tissue/organism scale adaptions?

ii. Acute/chronic/evolutionary timescale?

9) Do bears enter deep hibernation?a. How do polar bears and brown bears differ?

Trait Brown Bear Polar BearSize

Head

Paws

Fur

Diet

Swimming

Range

Breeding

Hibernation?

b. How might this affect our predictions about what will happen with these bears as climate change continues to change

11) What is likely to happen to polar bears as the climate continues to change?

12) What is likely to happen to Arctic Biodiversity more generally (It depends? On what?

10) Fill in the table