extreme biology Flashcards

Question

what is the role of the hypothalamus in reacting to changes in heat balance? and where is it located?

Answer 1

> located at the base of the brain above the pituitary glands (approx. the size of a pea) > major role is to keep the body in homeostasis > responds to signals from internal and external environment: e.g. temperature, hormone levels in the circulation, satiety, blood pressure > initiates responses to protect the body when core temperature changes serves as a thermostat: regulates core temperature to 37+/- degrees celcius

Answer 2

1. thermal receptors in the skin provide information about surface temperature of the body 2. temperature changes in blood perfusing the hypothalamus

Answer 3

physiological changes that improve heat tolerance

Answer 4

goal to reduce core temperature when exercising in the heat - increase rate of heat loss (i.e. increase sweat rate)

Answer 5

- increased sweat rate - reduced core temp - reduced HR 9 consecutive days of heat exposure 100 min per exposure intensity; 300kcal/hr temp; 48.9 degrees celcius

Answer 6

- vascular - muscle activity - hormonal

Answer 7

1. action potentials - at a tissue temperature of ~20 degrees celcius, conduction velocity, amplitude and repolarisation of action potentials is slowed 2. power output (in the muscle) - max power output drops by ~3% per degrees celcuis reduction in muscle temp. -incapacitation can occur at a mucle temp of 27 degrees celcius 3. VO2 max - reduced by 10-30% if core temp falls by 0.5-2 degrees celcius - in exercise stride frequency can increase/stride length decrease leading to slips and falls

Answer 8

VO2 max, or maximal oxygen consumption, refers to the maximum amount of oxygen that an individual can utilize during intense or maximal exercise. This measurement is generally considered the best indicator of cardiovascular fitness and aerobic endurance

Answer 9

~20 degrees celcius

Answer 10

mac power output (in muscles) drops by ~3% per degrees celcius reduction in muscle temperature

Answer 11

~27 degrees celcius

Answer 12

VO2 max reduced by 10-30% if core temp fall by 0.5-2 degrees celcius

Answer 13

(cold injury) - begins at ambient temp of ~12 degrees celcius wind speed>5mph - frostbite (freezing of tissue & formation of ice crystals) 1st degree; damage to superficial layer of the skin 2nd degree; blister on the skin 3rd degree; freezing of deeper tissue (subcutaneous and muscle) treatment 1st; simple re-warming 2nd; leave the blisters 3rd; hospitalisation (can result in amputation of effected area)

Answer 14

freezing of tissue and formation of ice crystals

Answer 15

- fibres in clothing traps air and warms it (creates barrier to heat loss) - thicker zone of trapped air next to skin provides better insulation - several layers traps air better (or thick clothing lined with fur/feathers/synthetic fibres) - be windproof - wick moisture away from body (to then evaporate)

Answer 16

initial rise in core temp (peripheral vasoconstriction, shunting of blood to core) ' theres no such thing as bad weather, just the wrong clothing' - billy connolly

Answer 17

it has been proposed that earth collided with a mars-sized planet around 4.5 billion years ago, something that would help explain its tilted axis

Answer 18

ice and snow tundra taiga montane temp, coniferous temp, broadleaf temp, grasslands trop. coniferous rainforest dry broadleaf trop. grasslands Mediterranean mangroves flooded grassland desserts

Answer 19

in highly seasonal climatic regions annual migration can help animals avoid the harshest time each year

Answer 20

1. obligate annual migration; all individuals migrate each year, usually to the same general areas 2. irruptive migration opportunistic movements that are determined by the local conditions 3. partial migration a part of the population migrates, the remaining stays, but pattern is annual and generally fairly regular

Answer 21

all individuals migrate each year, usually to the same general areas

Answer 22

opportunistic movements that are determined by the local conditions

Answer 23

a part of the population migrates, the remaining stays, but pattern is annual and generally fairly regular

Answer 24

- samoan and greek descriptions of migration of birds dates as far back as over 3000 years ago - aristole had an interesting view on cranes 'cranes migrate from the steppes of Scythia to the marsh-lands south of Egypt, where the Nile has its source. And it is here that they are said to fight with the pygmies; and the story is true, as there is actually a race of cave dwelling dwarfish men, and their horses are little in proportion too' - the exiled swedish archbishop Olaus Magnus moved the crane story to Greenland he also said that swallows spend their winter in lakes - hard evidence came in 1822 when the famous Pfeilstorch (arrow stork) was caught in Germany with a central African spear buried in its throat

Answer 25

thick snow forms an excellent insulating layer providing smaller animals and escape the habitat under the snow is called the subnivean zone and stays around 0 degrees celcius

Answer 26

subnivean zone ~ 0 degrees celcius

Answer 27

not accessible to large animals or those that need large territories to find food

Answer 28

to smaller animals some stay below all winter and others only shelter overnight or during bad weather

Answer 29

(different materials are different in their ability to conduct heat; as well as cold) - static insulation will need modulation

Answer 30

the ability of a substance to conduct heat or move heat from one location to another without the movement of the material conducting the heat. diamond - 1000 copper- 400 iron- 75

Answer 31

Designed to support performance in extreme cold, these layers keep you warm and dry in temperatures as low as 0°F while minimizing encumbrance. Powerful weather protection keeps out the rain, wind, and snow, and breathable insulation ensures that staying warm doesn't mean getting sweaty. Static insulation refers to insulation materials and systems that rely on physical barriers to resist heat flow without the need for active components like fans or heaters.

Answer 32

two liquids of different concentration to flow in opposing directions improves any transfer. *Counter-current heat exchange is an efficient method of heat transfer that optimizes temperature gradients, resulting in higher efficiency and effectiveness. found across the animal kingdom, e.g. in gills and kidneys to maximise their efficiency Fish Gills: Fish use counter-current exchange to maximize oxygen absorption from water. Blood flows in the opposite direction to water passing over the gills, allowing the blood to absorb the maximum amount of oxygen, even when oxygen levels in the water are low.

Answer 33

a rounded body-shape helps to minimise heat-loss, but inevitable some parts need to be thin and will also be more exposed to minimise any heat-loss, extremities are frequently keep at lower temperatures than that of the body core

Answer 34

a rounded body-shape helps to minimise helps to minimise heat-loss, but inevitable some parts need to be thin and will also be more exposed to minimise any hear-loss, extremities are frequently keep at lower temperatures than that of the body core ** A rounded body shape minimizes heat loss by reducing the surface area-to-volume ratio, which limits the area through which heat can escape relative to the body’s size. This is why animals in cold environments, like seals or polar bears, tend to have more compact, rounded bodies—they retain heat more effectively. However, certain body parts, such as limbs, tails, and even extremities like ears, must be thin or elongated for functionality, movement, and balance. These thinner areas are more exposed and have a higher surface area-to-volume ratio, which means they lose heat more readily than the body core.

Answer 35

tuna and some sharks. regional heterothermy is used by some large predatory fish, this helps them to keep their swimming muscles, brains and eyes working more effectively than their ectothermic prey. organisms that are able to maintain different temperature "zones" in different regions of the body.

Answer 36

- the different thermal properties of water and air makes it much more energetically expensive to be an endotherm in water - in nature, everything comes down to a balance between both costs and gains - early theories suggested that endothermy in fish would have enables them to spread towards colder polar seas - a recent survey of large marine predators showed that endotherms indeed dominate in polar regions, but this niche is typically occupied by marine mammals, not fish

Answer 37

Endotherms use internally generated heat to maintain body temperature. Their body temperature tends to stay steady regardless of environment. Ectotherms depend mainly on external heat sources, and their body temperature changes with the temperature of the environment.

Answer 38

the blood of marine fish have a lower osmotic concentration than seawater, therefore it freezes at -0.5 degrees celcius while the surrounding water freezes at ~-2 degrees celcius. since frozen water increases its volume, fish in polar seas face a lethal problem *Marine fish in polar seas face a unique survival challenge because their blood has a lower osmotic concentration than seawater, meaning it freezes at around -0.5°C. Seawater, due to its high salt content, has a lower freezing point of about -2°C. This creates a lethal situation: if the fish’s blood or bodily fluids begin to freeze, the ice crystals could expand within their tissues. Ice formation increases the volume of water, which could rupture cells and tissues, causing fatal damage to the fish. insects; on land, insects face the same problem, and both groups have evolved the same solution to survive. ANTI-FREEZE proteins these proteins bind to small ice crystals, even low concentration inhibit freezing AFPs have evolved independently many time across the animal kingdom and are a great example of convergent evolution

Answer 39

AFPs (anti-freeze proteins) have evolved independently many times across the animal kingdom and are a great example of convergent evolution *the process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities.

Answer 40

the process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities.

Answer 41

these proteins bind to small ice crystals, even a low concentration inhibit freezing. AFPs have evolved independently many times across the animal kingdom and are a great example of convergent evolution. produced in some fish and insects Many polar fish produce antifreeze proteins, which bind to small ice crystals in their body fluids and prevent them from growing. These proteins work by inhibiting the formation and expansion of ice crystals, allowing the fish’s blood to remain in a liquid state even at temperatures below their normal freezing point. This is critical because it stops the lethal effects of internal ice formation.

Answer 42

Homeotherms are those organisms, that maintains the internal body temperature under the influence of variable environmental conditions through their metabolic activities like shivering, sweating. Mammals and birds are homeotherms. homeotherms burn fuel quickly! - a high metabolic rate needs lots of energy, especially when subjected to a cold climate

Answer 43

smaller relative metabolic rate is typically higher in smaller animals compared with larger ones

Answer 44

1. torpor; shorter periods of inactivity, often with reduced temperature and metabolism, used to handle daily temperature and food fluctuations 2. hibernation; prolonged reduction of the body temperature and metabolism (winter dormancy) * the regular return to normal temperature seen during hibernation is not yet fully understood

Answer 45

shorter periods of inactivity, often with reduced temperature and metabolism, used to handle daily temperature and food fluctuations (way in which fuel is saves)

Answer 46

prolonged reduction of the body temperature and metabolism (winter dormancy) *the regular return to normal temperature seen during hibernation is not yet fully understood (a way in which fuel is saved)

Answer 47

artic ground squirrels live in arid artic regions and normally hibernate from september to may. in extreme cases their body temperature drops to -2.9 degrees celcius, but their brain stays just above 0 degrees celcius not fully understood how they survive freezing, but most likely by cleaning their blood of any potential ice nucleators to keep it supercooled *The initiation of the transition from the liquid state to ice is called nucleation. Substances that facilitate this transition so that it takes place at a relatively high sub-zero temperature are called ice nucleators. Many living organisms produce ice nucleators. the potential of keeping human tissues alive at sub-zero temperature have made the squirrels the focus of ongoing organ transplant research **this allows the squirrels to save on metabolism during the winter

Answer 48

deserts cover 1/3 of all land area on earth

Answer 49

the searing day-time temperatures put desert-living animals at a serious risk of overheating at night time the temperatures drop

Answer 50

evaporation cooling reflection reducing contact use of counter-current systems insulation and localising fat stores refuges *finding enough water is another challenge that needs to be solved to survive in a desert habitat

Answer 51

darkling beetles (tenebrionidae) in Namibia have evolved ways to access water in one of the driest deserts found anywhere on Earth. the surface of their elytra (cover wings) have a texture that turn fog particles into droplets. their hindlegs are elongates to help them align against the fog drifting from the sea

Answer 52

Thermophilic scavengers are organisms that thrive in high-temperature environments and feed on dead organic material, often playing crucial roles in nutrient recycling in extreme habitats. "Thermophilic" means "heat-loving," so these scavengers are specifically adapted to survive and function in hot environments, live in one of the hottest environments on Earth, feeding on victims of extreme heat surface temperature reaches up to 70 degrees celcius (their own thermal maxima is 'just' 53.6 degrees celcius) minimise heat build-up by short foraging trips, elevated objects, and reflective hairs. do not use pheromones to find their nest, instead navigate by 'dead reckoning' with an internal solar-compass and step-counter spiralling search pattern used if nest is not found, **in 1966 the US air force employed this method to locate a lost nuclear bomb

Answer 53

minimise heat build-up by short foraging trips, elevated objects, and reflective hairs. do not use phermones to find their nest, instead navigate by 'dead reckoning' with an internal solar-compass and step-counter

Answer 54

1. small surface area to body volume ratio; strongly reduces heat loss compared with smaller and less rounded animals 2. white, translucent fur; provides camouflage in icy landscape making it easier to stalk and catch prey 3. large, dimpled feet; allows easier grip and spreads weight of the entire animal over a large area 4. acute sense of smell; can smell prey hiding under the ice and at a far distance 5. thick fat and fur layers; direct protection against the cold and also used as fuel during hibernation. fat metabolism acts as water source. 6. water repellent fur; water particles bead off, reducing the risk of water freezing on to the fur coat 7. rear young in a den; protects young from cold winds until most of their fur growth have finished 8. closable nostrils; prevents water from entering into nose when swimming and diving

Answer 55

'excessive/stressful demands imagined /real, made on an individual to think, feel, or act in particular ways. The experience of pressure is often the source of cognitive and affective discomfort or disorder, as well as of maladaptive coping strategies the correlation of which may be a mediate or end goal in psychotherapy'

Answer 56

stress is the response stressor is a place/event/situation which causes the response

Answer 57

arousal; general physiological and psychological activation of an organism which varies on a continuum from deep sleep to intense excitement stress; non-specific response of the body to any demand placed upon it *directionality (good stress= eustress) anxiety; an unpleasant psychological state in reaction to perceived stress concerning the performance of a task under pressure (cognitive/somatic) state/trait

Answer 58

cognitive anxiety refers to the negative thoughts and doubts someone may experience. somatic anxiety relates to the physiological. symptoms brought on by high pressure moments.

Answer 59

trait anxiety is a stable part of how someone thinks and feels, state anxiety is a temporary state that only occurs in response to or anticipation of stressful situations. For example, a person might experience state anxiety when they are late for work but calm down once they get there on time.

Answer 60

- perceived imbalance between what is being asked of the person and the person's ability to cope with those demands, and where failure has severe consequences perceived sufficient ability to cope vs perceived demands of task the interpretation of threat

Answer 61

alarm; fight/flight activation causes stress resistance incorporated ability to cope with stress resistance; body starts to react to stress exhaustion: resources are depleted, stress resistance starts to decrease maladaptive response

Answer 62

The perception of events as stressors involves diverse and different networks depending whether it is a physical/psychological stressor SNS (fast); triggers arousal in response to stressor via release of adrenaline from adrenal glands HPA axis- hypothalamic-pituitary-adrenal (slow); hypothalamus releases corticotrophin-releasing factor in moments of stress, process temporarily boosts immune function and decreases pain sensitivity

Answer 63

fast acting; triggers arousal in response to stressor via release of adrenaline from adrenal glands

Answer 64

slow acting ; hypothalamic-pituitary-adrenal, hypothalamus releases corticotrophin-releasing factor

Answer 65

boosts immune function and decreases pain sensitivity

Answer 66

SAM pathway leads to short-lasting responses e.g. alertness, vigilance, situation appraisal, enabling a strategic decision to face the challenge in the initial phase of a stressful event HPA pathway is slower acting (hypothalamic-pituitary-adrenal) hypothalamus releases corticotrophin-releasing factor cortisol 'stress hormone' promotes blood sugar availability, regulate metabolism, reduce inflammation hypothalamus (coricotrophic releasing hormone) --> pituitary gland (adrenocorticotrophic hormone) --> adrenal glands (cortisol)

Answer 67

stress hormone; promotes blood sugar availability regulate metabolism reduce inflammation

Answer 68

corticotropic releasing hormone

Answer 69

adrenocorticotrophic hormone

Answer 70

leads to short-lasting responses e.g. alertness, vigilance, situation appraisal, enabling a strategic decision to face the challenge in the initial phase of a stressful event

Answer 71

stress response is adaptive; prepares body for challenge on it repeated acute bouts, chronic stress or perceived as intense leads to maladaptive responses (biological/behavioural /psychological) GI problems perspiration muscle tension redirection of blood flow to large muscles elevated HR + increased blood pressure dilated pupils maladaptive cognitions and emotions elevated respiration

Answer 72

Many people, over the course of their lives, have experienced acute stress, a dramatic physiological and psychological reaction to a specific event. Chronic stress, however, is a consistent sense of feeling pressured and overwhelmed over a long period of time.

Answer 73

vulnerability (adversity/environmental stress/familial stress) acts on adrenal glands which release glucocorticoids glucocorticoids have neurotoxic effects neurotoxicity hypothesis; high levels of GC for long periods has harmful effects on HPA-axis regulation, that impacts hippocampus and memory - neurotoxic effects of glucocorticoids on brain - chronically high cortisol levels can lead to cognitive impairments; in attention, memory and emotion processing - vulnerability to mental health disorders

Answer 74

on top of kidneys Adrenal glands, also known as suprarenal glands, are small, triangular-shaped glands located on top of both kidneys. Adrenal glands produce hormones that help regulate your metabolism, immune system, blood pressure, response to stress and other essential functions.

Answer 75

The hippocampus is a part of your brain that's responsible for your memory and learning. This small structure helps you remember, both short- and long-term, and gain awareness from your environment.

Answer 76

Glucocorticoids are steroid hormones produced from the cortex of adrenal glands . - have neurotoxic effects on brain (chronically high cortisol levels can lead to cognitive impairments; in attention, memory and emotion processing) *cortisol is a glucocorticoid

Answer 77

> traumatic events e.g. military combat, traffic collision, victim of crime, bereavement > life changes e.g. moving house, graduating, retiring > hassles e.g. finding parking/traffic, burst pipe to be fixed > other stressors e.g. job burnout/uncertainty, exams > situational factors competition, inadequate kit/facilities/poor weather > intrapersonal factors goals/demands/expectations, perceptions of readiness > interpersonal factors teammates/coaches/spectators, placing demand/expectations on athletes/conflicts

Answer 78

- interpersonal ego-threat - physical danger - ambiguity (fear of unknown) - disruption in daily routine - social evaluation

Answer 79

1. facing objective demands 2. interpretation the objective demands (perceived as threatening or non-threatening) 3. response to perceived imbalance - raised somatic anxiety (muscle tension, altered movement patterns) - raised cognitive anxiety (disrupted concentration, attentional control and can end up worrying about their thoughts of worry) 4. behavioural consequences as result of stage three *cognitive anxiety refers to the negative thoughts and doubts someone may experience. somatic anxiety relates to the physiological.

Answer 80

CLUTCH: improved performance under heightened pressure characteristics; fully absorbed on task, high confidence, sense of control, enjoyment, enhanced motivation to succeed, focus, effort, heightened self awareness, high arousal levels, absence of negative thoughts of consequence if don't win. strategies to achieve clutch; deliberate focus, optimal arousal levels, confidence in ability CHOKING: sudden & significant decrement in normal expert levels of performance under conditions of perceived pressure performance paradox mechanism is unclear (attentional theories- self focus, distraction) *pre-performance routines useful to prevent choking

Answer 81

disposition to avoid failure and/or capacity for experiencing shame/humiliation as a consequence of failure FoF- motivation to avoid failure: - predisposition to perceive threat in chellenges and this experience anxiety - associated with anticatory shame - consequences of failure are perceived as hugely (negatively) impactful > lower self-estimate (e.g. im no good) > non-ego punishment (e.g. waste of time to not reach goals) > reduced social value (e.g. others will think less of me if i fail) - positive relationship with coaching style (controlling = hFoF, autonomoy supportive = lower FoF - performance failure appraisal inventory (PFAI)

Answer 82

performance failure appraisal inventory The Performance Failure Appraisal Inventory (PFAI) is a psychological assessment tool used to measure individuals' fear of failure in performance settings, typically applied in areas such as sports, academics, and work. The PFAI evaluates how much someone worries about failure and what specific negative consequences they associate with failing. Understanding fear of failure is critical because it can significantly impact motivation, emotional responses, and overall performance in various high-stakes settings.

Answer 83

High Fear of Failure (hFoF): Individuals may benefit from interventions like cognitive-behavioral therapy (CBT), resilience training, and self-compassion exercises to manage their fear of failure and reduce the impact on performance and mental health. Lower Fear of Failure (lowerFoF): Individuals with a low fear of failure often already have adaptive responses to setbacks. However, they can benefit from continued support to maintain resilience and a positive growth mindset, which sustains performance and personal development over time.

Answer 84

the role of mental processes and behaviour in promoting personal assets and protecting an individual from the potential negative effect of stressors

Answer 85

develop strategies/learn techniques to reduce perceived demand/increase ability to cope forms of 'therapy' e.g. CBT/ACT - release breathing -imagery social support ACT; Acceptance and commitment therapy (ACT therapy) is a type of mindful psychotherapy that helps you stay focused on the present moment and accept thoughts and feelings without judgment. CBT; Cognitive behavioural therapy (CBT) is a talking therapy that can help you manage your problems by changing the way you think and behave.

Answer 86

ACT; Acceptance and commitment therapy (ACT therapy) is a type of mindful psychotherapy that helps you stay focused on the present moment and accept thoughts and feelings without judgment. CBT; Cognitive behavioural therapy (CBT) is a talking therapy that can help you manage your problems by changing the way you think and behave.

Answer 87

the amount of force applied at right angles to the surface of an object per unit area pressure (Pa) = force normal to a surface (N)/ area of surface (m^2) (F= P x A) F= force normal to a surface (N) Pa=pressure A=area of that surface (m^2)

Answer 88

total pressure duration of exposure to pressure state of activity (resting/exercising) temperature drugs in the body gas mixtures inspired rate of ascent/descent

Answer 89

the pressure exerted by an individual gas in a mixture is known as its partial pressure

Answer 90

The partial pressure of a gas is the amount of pressure that the gas contributes to the total pressure of that gas mixture. Per Henry's law, if the pressure of a gas over a liquid increases, the amount of gas dissolved in the liquid increases proportionally.

Answer 91

compares having a martini every 10m of depth you descend. This means by the time you are at 30-40m (3-4 martini's) depth it's no surprise you may feel a little tipsy! - reduced mental activity - perception of time affected - perceptual narrowing - light-headedness - vomiting (nitrogen narcosis)

Answer 92

Nitrogen narcosis is a condition that affects divers at depth, caused by the anaesthetic effects of nitrogen under high pressure. As divers descend and the surrounding pressure increases, nitrogen—one of the primary gases in the air—dissolves more readily into the blood and tissues. Under high pressure, nitrogen has a narcotic effect on the central nervous system, leading to symptoms like euphoria, impaired judgment, slowed reaction times, and, in severe cases, hallucinations. The deeper a diver goes, the stronger these effects become, creating a state similar to alcohol intoxication. Martini's Law is an informal rule often used to describe the effects of nitrogen narcosis. It states that for every 10 meters of depth below 20 meters, a diver experiences an effect similar to drinking one martini

Answer 93

decompression sickness (DCS) retention of dissolved nitrogen on decompression causes bubbles symptoms; joint pain, rashes, paralysis, death

Answer 94

The bends, or decompression sickness (DCS), is a dangerous condition that occurs when dissolved gases (mainly nitrogen) come out of solution in a diver's body too quickly upon ascending. This rapid release of gas forms bubbles in the blood and tissues, leading to symptoms that can range from joint pain and dizziness to paralysis and even death. The process of decompression sickness is fundamentally related to Henry's Law, which states: The amount of a gas that dissolves in a liquid (like blood) is proportional to the partial pressure of that gas above the liquid.

Answer 95

ear and sinus pressure nitrogen narcosis ruptured capillaries blackout inability to inspire gasses collapsed lungs the bends death

Answer 96

density decreases. altitude increase= non-linear aur density decrease *density of air is not constant ait 'gets thinner'

Answer 97

when humans are exposed to altitude >5500m - partial pressure of oxygen (PaO2) decreases with altitude - 1/3 of sea level POa2 at Everest summit (8848m) - arterial PO2 reduced - plasma volume decreases by ~20% - sensed by carotid body chemoreceptors > increased respiratory rate > increased heart contractility and rate > increased urination > non-essential body functions suppressed

Answer 98

- occur > 4 days at altitude - adaptation can be approximated by multiplying the altitude in kilometres by 11.4 days - erythropoietin (EPO) produces more haemoglobin - increased ability to transport oxygen - decreased plasma volume - increased capillarisation in skeletal muscle tissue - increased muscle mitochondria - right ventricular hypertrophy *Right ventricular hypertrophy (RVH) is an abnormal enlargement or pathologic increase in the right ventricular muscle mass as a maladaptive response to chronic pressure overload.

Answer 99

multiplying the altitude in kilometres by 11.4

Answer 100

- 14 summits above 8000m - extreme hypoxia - O2 used up faster than it can be replenished - no human can acclimatise - rapid deterioration of bodily functions - loss of consciousness

Answer 101

1. HACE high-altitude cerebral oedema - retention of cerebral fluid - 'brain swelling' - loss of consciousness >fever >ataxia - altered mental state - hypocapnia (low CO2) 2. AMS acute mountain sickness - headache - GI disturbance - nausea - vomiting - insomnia - fatigue - dizziness 3. HAPE high-altitude pulmonary oedema - pulmonary hypertension - increased hydrostatic pressure - increased permeability of vascular epithelium - 'stress failure' - leakage of cells and protein into alveoli

Answer 102

(acute disorders at altitude) HAPE high-altitude pulmonary oedema - pulmonary hypertension - increased hydrostatic pressure - increased permeability of vascular epithelium - 'stress failure' - leakage of cells and protein into alveoli

Answer 103

(acute disorders at altitude) AMS acute mountain sickness - headache - GI disturbance - nausea - vomiting - insomnia - fatigue - dizziness

Answer 104

HACE high-altitude cerebral oedema - retention of cerebral fluid - 'brain swelling' - loss of consciousness >fever >ataxia - altered mental state - hypocapnia (low CO2)

Answer 105

- no gravity to move blood and other body fluids to legs - 'puffy head, chicken legs' - reduced cardiac work- decreased CO - muscle wastage - reduction in bond density - dizziness >exposure to high-energy cosmic radiation increases risk of neurodegenerative disease >eye abnormalities may rise die to UV exposure and increased intracranial pressure >due to microgravity, disruption of fluids to the upper body result in 'puffy face' appearance >nasal congestion due to fluid redistribution causes anosmia (loss of smell) and diminished taste >heart stroke volume decreases as cardiovascular system adapts to microgravity. red blood cell number also decreases. >musculoskeletal adaptation to microgravity leads to loss of muscle mass and bone density >blood plasma volume is reduced by increased kidney output. elevated calcium secretion results in increased risk of kidney stones.

Answer 106

organisms that grow optimally in environments considered extreme **dominant in earth's evolutionary history > an extreme environment 40M years ago > life may even have begun in deep sea hydrothermal vents have continued to thrive in extreme conditions > one of most abundant life forms > biological 'dark matter' many yet to be discovered

Answer 107

- very slow/fast growing - very large/small - very large genome - extreme cellular complexity - some are not really bacteria (archaea)

Answer 108

microorganisms which are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient group which is intermediate between the bacteria and eukaryotes.

Answer 109

2 micro meter long 0.7 micro meter cubed volume 1 chromosome 4.6 Mbp genome 4,300 protein coding sequences 20 minute doubling time

Answer 110

- in salt and fresh water globally > discovered in sargasso sea- very low nutrients, relatively devoid of life - possibly most numerous bacterium globally > ~2x10^28 candidatus P. communis and relatives >total weight> all fish in sea - one of smallest self-replicating cells known > an ultramicrobacterium (V<0.1 micro meters cubed), 0.4-0.9 micrometer x 0.1-0.2 micrometer. > genome 1.3 Mbp, 1354 protein genes, 35 RNA genes - understanding ultramicrobacteria important for synthetic biology >e.g. creation of self-replicating synthetic organisms based on minimal genomes

Answer 111

large and extreme polyploidy. *the heritable condition of possessing more than two complete sets of chromosomes most bacteria and archaea rely on diffusion to move metabolites and biomolecules short distances. exception; bacterial symbiont of surgeonfish -epuloposcium spp. latin; 'a guest of banquet fish L> 600 micro meters V~3x10^8 micro meters cubed homozygous: 10s of 1000s genome copies how does it maintain large size? - highly folded cell membrane increases effective surface area - arrangement of geneomes around cell periphery may permit regional responses to local stimuli abundance of genome copies may permit unstable genetic feature common in eukaryotes, rare in bacteria - long (10bp) poly(A) repeat in dnaA >essential gene encoding dnaA which activates DNA replication initiation > functional significance of mononucleotide repeat unknown epulopiscium has acquired some characteristics and advantages of eukaryotic cells!

Answer 112

the heritable condition of possessing more than two complete sets of chromosomes

Answer 113

ACHROMATIUM - large (125 micro metwe), hyperployploid and only known heterozygous bacterium ~300 different chromosomes - allelic diversity far exceeds that of typical bacterium - common worldwide, spanning T, salinity, pH and depth ranges normally resulting in bacterial speciation - anchromatium from differing ecosystems (freshwater, saline) equally functionally equipped but differ in gene expression patterns by transcribing only relevant genes - hypothesis; environmental adaptation occurs by increasing copy number of relevant genes across chromosomes, without losing irrelevant ones, maintaining ability to survive any ecosystem

Answer 114

bacterial growth rates very widely. several times/hour in nutrient rich lab conditions once/year in nutrient poor subglacial lakes

Answer 115

may organisms vary ribosomal abundance as function of growth conditions translation time/ribosome (~7min) places inherent limit on bacterial growth rate >could be surpassed only if cell could 1. increase polypeptide elongation rate 2. reduce total mass of ribosomal protein and rRNA

Answer 116

prokaryotes but not bacteria like bacteria - size and shape - reproduce asexually by binary fission, fragmentation or budding unlike bacteria - genes and metabolic pathways more closely related to eukaryotes - membrane lipid e.g. archaeol (not e.g. phosphatidylcholine) - do not form endospores major part of life on earth- key to animal microbiota not pathogens/parasites- mutualists and commensals *hard to grow in lab first observed archaea were extremophiles e.g. haloquadratum walsbyi > discovered in brine pool (sinai, egypt) > phosotrophic halophile -survives [NaCl] ~3M [MgCl2] ~2M -among most haloresistant organisms general halophile high-salt strategy - increase internal osmolarity by accumulating K+ ions in cytoplasm, requires 2xATP/K+ general halophile in low-salt strategy - de novo synthesis/uptake of osmoprotectants maintain osmotic balance and establish proper turgor pressure

Answer 117

temp. ~10-37 degrees celcius relative humidity ~30-50% water activity ~0.75 [salt] ~0.15-0.5M pH ~7 pressure ~0.1MPa ionising radiation ~0.6 mSv/year

Answer 118

thrive at 41 degrees celcius (moderate) to 122 degrees celcius (hyperthermophiles) hyperthermophilic and mesophilic enzymes highly similar - a.a. sequences tyically 40-85% similar - 3D structures superimposable - same catalytic mechanisms main source of industrially important thermostable enzymes - thermus aquaticus (Taq DNA polymerase) > used in PCR to amplify short segments of DNA - thermophilic clostridium spp > used to produce biobutanol from corn hypothesis; hyperthermophillic enxymes more rigid than mesophillic homoloques at mesophillic T, rigidity prerequisite for high protein thermostability. rigidity arises from more ion-pairs e.g. in glutamate dehydrogenase (GDH) - 45/subunit in pyrococcus furiosus -26/subunit in clostridium symbiosum high melting temperature (Tm), long half-life at high T.

Answer 119

cell fluctuations reveal prokaryotic response to long-term climatic and environmental processes north greenkkand eemian ice drilling core - 2km deep= 80,000 years ago - 3.6x10^5 cells/ml >85% viable >hard to culture >0.00028% success rate -4 isolates cultured > acinetobacter > firmicuted x2 > gammaproteobacteria general psychrophile cold tolerance strategies - high level of unsaturated and short chain fatty acids (SCFA) - cold shock proteins (CSP) > nucleic acid chaperones- prevent formation of mRNA 2 degrees structures at low temperature thus facilitate translation initiation - protein chaperones (assist folding/unfolding) - anti-freeze proteins (AFP) restrict ice growth on protein surfaces - mannitol and other solutes accumulate in cytoplasm as cryo-protectants -prevents protein aggregation - carotenoids support membrane fluidity and prevent UV damage

Answer 120

general psychrophile cold tolerance strategies - high level of unsaturated and short chain fatty acids (SCFA) - cold shock proteins (CSP) > nucleic acid chaperones- prevent formation of mRNA 2 degrees structures at low temperature thus facilitate translation initiation - protein chaperones (assist folding/unfolding) - anti-freeze proteins (AFP) restrict ice growth on protein surfaces - mannitol and other solutes accumulate in cytoplasm as cryo-protectants -prevents protein aggregation - carotenoids support membrane fluidity and prevent UV damage

Answer 121

atacama desert, chile - oldest desert ~ 90M y.o. - ave. rainfall < 5mm/year -hyper arid - pH extremes - highest UV levels on earth - mars-like soil importance of extremophile research medicine: s. atacamensis synthesises ansamycin and 22-membered macrolactones - antibacterial and antitumor activities climate change: response to drought by bacteria important to crops bioremediation: of soils in extreme dry conditions space science: survival on mars general xerotolerant survival strategies - evasion of environmental stress - spore formation - adaptive mechanisms > preventing H2O loss and increasing H2O retention through osmoprotectant accumulation (trehalose, L-glutamate, glycine betaine) - increasing H2O retention through cell membrane modifications - production of extracellular polymeric substances (EPS) - synthesis of DNA-repair proteins

Answer 122

- evasion of environmental stress - spore formation - adaptive mechanisms > preventing H2O loss and increasing H2O retention through osmoprotectant accumulation (trehalose, L-glutamate, glycine betaine) - increasing H2O retention through cell membrane modifications - production of extracellular polymeric substances (EPS) - synthesis of DNA-repair proteins

Answer 123

1. collect 2. culture 3. examine 4. extract and sequence genomic material 5. knock out key genes and look at effect on organism 6. express key genes in workhorse bacteria 7. solve structures of key proteins

Answer 124

deepest ocean bottom; 11km deep

Answer 125

habitat fragmentation hunting/harvesting climate change pollution

Answer 126

Fragmentation happens when parts of a habitat are destroyed, leaving behind smaller unconnected areas. This can occur naturally, as a result of fire or volcanic eruptions, but is normally due to human activity. A simple example is the construction of a road through a woodland. 1. natural 2. anthropogenic processes in population biology are affected by habitat patchiness (fragmentation) low degrees of fragmentation and high connectivity = good small and isolated populations = bad effects are magnified over time

Answer 127

will affect species differently; can be grouped into two main categories 1. specialist species 2. generalist species carnivores are vulnerable to habitat loss - lower population densities - require large home ranges - often persecuted by humans

Answer 128

- fragmentation also leads to linear features in the environment - roads, fences, pastures, powerlines negatives; > restrict movement > increase mortality > increase hunting and/or poaching > increased stress from visual and noise stimuli positives for some > carnivores > facilitate travel > forage further and faster > trap prey on edges of habitats > scavenging on roads

Answer 129

spotted quolls (dasyurus maculatis) and tasmanian devils (sarcophilus harrisii) are generalist medium sized carnivores habitat plasticity- trait allowing them to adapt to fragmentation pasture cover for foraging- slower movement roads- movement was faster and straighter - directional travel **placticity='the ability of individual genotypes to produce different phenotypes when exposed to different environmental conditions'

Answer 130

'the ability of individual genotypes to produce different phenotypes when exposed to different environmental conditions'

Answer 131

evolution of wild populations can be impacted by harvesting leads to changes in -morphological -behavioural - life history traits >natural selection bring local adaptations to the natural environment >selective harvesting impedes adaptive evolutionary processes >potential delay in the recovery of populations

Answer 132

- sustained size selection on vertebrate population = shift in age structure - traits targeted by hunters positively correlated with age - african elephants (locodonta africana) are of particular risk - disproportionally affected- older ages classes and males have larger tusks - poaching is the driver- contemporaty tusk evolution in african elephants?

Answer 133

10,000 x slower typical rate of niche evolution (500 species) is 10,000 x slower than the rate that is required to keep up with climate change projections

Answer 134

1. exposure 2. sensitivity 3. resilience 4. adapt

Answer 135

1. shift in range distribution within climate tolerant limits 2. remain and adjust I. genetic composition II. phenotypic plasticity 3. extinction I. local level II. global level

Answer 136

rapid shift in environmental stability challenges the adaptive nature of marine mammals species that reply on the ice are particularly vulnerable

Answer 137

ice obligate ice associated seasonally migrant

Answer 138

- expend their geographical range - will benefit from net loss in sea ice - scoring of resilience to change through adaptation - chukchi region scores the highest for resilience for seasonal migrants - seasonal migrants can adapt to their changing environment- generalise species

Answer 139

- micro evolution = heritable shifts in allele frequencies in a population - morphological features; (in relation to climate change is coat colour)

Answer 140

phenotypic plasticity = where a single genotype gives rise to different phenotypes in different circumstances epigenetic effect the animal itself changes not future lineages in response to environmental change in response to climate change; 1. acclimation 2. acclimatisation 3. learning

Answer 141

pelt colour in springbok (antidorcas marsupialis) thermoregulatory significance black springbok reduce their metabolic costs when it is cooler black absorbs solar radiation more efficiently trade off during periods of high heat

Answer 142

soay sheep in st kilda climate change has meant that winters are milder reduction in average body mass - 0.3% in senescent - 0.8% in yearlings decrease in hindleg length body weight decline rather than a decline in body condition proposed mechanism; less reliance on fat reserve

Answer 143

In conduction, heat transfer occurs between objects by direct contact. In convection, the heat transfer takes within the fluid. In radiation, heat transfer occurs through electromagnetic waves without involving particles. The heat transfer takes place due to the difference in temperature.

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