Functional marine biology Flashcards
1
Q
What is functional biology?
A
Function refers to the way organisms solve problems and how physical and chemical factors constrain and select solutions.
2
Q
What is the law of tolerance?
A
Each individual has a range of tolerance for every physical variable. The distribution of a species is controlled by that environmental factor for which the organisms have the narrowest range of tolerance.
3
Q
What is homeostasis?
A
The tendency towards a relatively stable equilibrium among interdependent elements
4
Q
What is stress?
A
A state produced by an environmental or other factor which extends the adaptive responses of an animal beyond the normal range
5
Q
What are different sources of stress?
A
*age
*disease
*parasitism
*water quality
6
Q
What are thermodynamics?
A
The relationship between temperature and a reaction. Q10 describes this relationship in biological processes
7
Q
What is Q10?
A
The temperature coefficient. It represents the factor by which the rate of a reaction (R) increases for every 10°C rise in temperature (T).
8
Q
Why does Q10 contradict the Arrhenius equation?
A
The Arrhenius equation describes the relationship between temperature and a reaction rate in a chemical state. It shows there should only be a 2% rise in rate of reaction for a 10°C rise. Q10 contradicts this because biological systems represent the summation of many individual reactions, which are catalysed by enzymes
9
Q
What is the role of enzymes on thermal tolerance?
A
Enzymes increase the efficiency of biological reactions. Increasing temperature means there is more kinetic energy so more collisions but after a certain point enzymes begin to denature.
10
Q
What is a eurytherm?
A
A species with a wide temperature range - this means they may have a wide geographical distribution
11
Q
What is a stenotherm?
A
A species with a narrow temperature range
12
Q
What is a poikilotherm / ectotherm?
A
A species with body temperature equal to the seawater temperature
13
Q
What is a homeotherm / endotherm?
A
A species who’s body temperature is constant and controlled
14
Q
What is the difference between a regulator and conformer?
A
Conformers don’t regulate their body temperatures whereas regulators do. Regulators have a zone of stability where homeostasis is maintained
15
Q
What are poikilothermic eurytherms?
A
They have a wide temperature range but don’t regulate their own temperature so match outside temperature conditions. They are found in lots of different geographical temperature areas.
16
Q
What are poikilothermic stenotherms?
A
They don’t regulate their own body temperature and have a narrow temperature range. Found in a small geographical temperature range.
Stenothermy can often give rise to striking separations of species’ ranges, even on very small spatial scales.
17
Q
What is adaption?
A
The genetic process by which a population changes to accommodate environmental factors
18
Q
What is acclimation?
A
The physiological changes an individual makes to minimize the effects of stressors. Does not require genetic modification, only physiological changes.
19
Q
What is acclimatisation?
A
A coordinated response to several simultaneous stressors (e.g. temperature, humidity and photoperiod). , perhaps due to moving to a new geographical area
20
Q
What are different poikilothermic adaptions?
A
*Intertidal polychaetes burrow into sediments to avoid over-heating
*Purple sea stars pump themselves up with cold seawater prior to being exposed at low tide
*Some antarctic fish have clear blood because instead of synthesizing blood hemoglobin, they produce antifreeze glycoproteins allowing them to swim in polar regions up to -1.8 degrees
21
Q
How is heat conserved in fish?
A
Most fish are true poikilotherms but a number of large fish maintain above-ambient core temperatures using counter-current heat flow exchange.
22
Q
What are examples of insulation in aquatic vertebrates
A
*Dolphins have heat exchangers in their finns
*Whales have heat exchangers in their tongue
*Aquatic birds have heat exchangers in their legs
23
Q
What is osmoregulation?
A
The active regulation of osmotic pressure of body fluids
24
Q
What is excretion?
A
The process of removing metabolic waste
25
What do aquatic animals secrete?
Aquatic animals secrete ammonia. They have excess of hydrogen as they are surrounded by water so they utilize 3 H atoms for waste
26
What do ureotelic animals secrete?
Ureotelic animals secrete urea and utilize two H atoms as they only have a steady flow of water
27
What do uricotelic animals secrete?
Uricotelic animals use 1 H as they have a limited supply of water E.g. birds
28
How does a high water potential e.g. pure water affect plant and animal cells?
Water moves into the cell by osmosis down a water potential gradient. Animal cells are cytolysed and burst open. Plant cells have a cell wall which prevents bursting but the membrane pushes against the cell wall and it becomes turgid.
29
How does low water potential e.g. concentrated sugar solution affect plant and animal cells?
Water moves out of the cell by osmosis down a water potential gradient. Animal cells shrink and appear wrinkled and become cremated. Plant cells membranes pull away from the cell wall and becomes plasmolysed.
30
Where did animal life begin?
Animal life began in the sea where it flourished because of the relative consistency of the environment for example salt concentration. The body fluids of most marine invertebrates have a similar composition to that of the seawater.
31
What is the osmotic concentration of most marine animals?
Osmotic concentration is close to that of their medium (seawater) and do not experience significant water losses or gains
32
What are osmoconformers?
Species whos overall osmotic concentration is always approximately isosmotic with seawater. Most marine invertebrates are osmoconformers.
33
What are osmoregulators?
Species that regulate the ionic and osmotic composition of their body fluids to maintain a stable (within limits) internal fluid composition. For example migratory fish and some estuarine invertebrates
34
What techniques do osmoconformes use to be isosmotic with seawater?
*Body volume changes as water enters or leaves by osmosis
*Some animals burrow into sediments to avoid rapid changes in external salinity.
35
What are euryhaline animals?
Animals which can tolerate a wide range of salinities, usually by a combination of osmoconforming and osmoregulatory processes; most estuarine species
36
What are stenohaline animals?
Animals which are restricted to a narrow salinity range. They still have active ionic and osmotic regulators; most marine teleosts
37
How do animals regulate osmotic pressure?
Cells are isosmotic to body fluids, but have a different ion composition (higher K+ & lower Na+). If the osmotic concentration of body fluid changes, this is matched by changes of organic molecules in cells; Organic molecules, mainly amines and amino acids are used inside cells as osmotic regulators.
38
What amino acid do most marine invertebrates use for osmotic regulation?
glycine
39
Why cant all amino acids be used for osmotic regulation?
Some amino acids cant be used for osmotic regulation intracellularly as they interact with proteins and change their conformation. e.g. lysine and arginine are not found in the same concentration as osmotically important amino acids.
40
What is salinity-mediated osmoregulation?
The concentration of free amino acids in cells is regulated by changing levels of protein degradation or synthesis. These levels increase during salinity stress and are consistent with cell volume regulation
41
What are the 3 types of osmotic marine vertebrates?
*Iso-osmotic with seawater: e.g. Myxine (hagfish)
*Hypo-osmotic regulators (with a higher concentration of body fluid than surrounding): most marine vertebrates
*Air-breathing marine vertebrates (with no gills)
42
What technique do elasmobranchs use to maintain iso-osmotic pressure with seawater?
Elasmobranchs (e.g. dogfish) retain large amounts of urea in their body fluids. Although they have lower salt content than seawater, increasing the urea concentration makes them iso-osmotic. The urea is used in the coelacanth and liver
43
How do organisms that live in both freshwater and saltwater regulate osmotic pressure?
salmon migrate between oceans and freshwater
At sea they drink seawater, excrete salt from gills and produce little urine. In freshwater they stop drinking, take in salt via gills and produce lots of dilute urine.
44
How do the Air-breathing marine vertebrates birds and reptiles regulate osmotic pressure?
They face more problems than fully terrestrial species as no freshwater to drink & high salts in food (algae & invertebrates isosmotic to seawater). Birds and reptiles have salt glands in the head that secrete hyperosmotic NaCl solution.
45
What is special about Pelodiscus sinensis - the Chinese swamp turtle
Its the only vertebrate that excretes urea from its mouth. its an adaptation to brackish water
46
How do the air-breathing marine vertebrates mammals regulate osmotic pressure?
They are able to form hyperosmotic urine (i.e. more concentrated than seawater). This allows removal excess of salts from food or ingested seawater; humans do not have this ability hence the inability to drink seawater
47
What is the mechanism of excretion in invertebrates?
Lower invertebrates such as Porifera still rely on diffusion to remove nitrogenous waste. Higher invertebrates have a tubular filtration system
48
What are the processes of a tubular system?
*Filtration
*Selective reabsorption and secretion
*Excretion
49
What is bioenergetics?
The study of energy flow through living systems
50
What is respiration?
Respiration includes the transport of oxygen into the body/cells and transport of carbon dioxide out of the body.
51
What is metabolism?
Metabolism includes the cellular processes by which energy is obtained through the breakdown of glucose (includes cellular respiration).
52
What are the steps of aerobic respiration?
It starts with glycolysis in the cytoplasm where a glucose molecule is broken down into pyruvate. If there is sufficient oxygen for aerobic respiration, pyruvate is transported to the mitochondria where it is converted into ATP through the Krebs cycle. ATP is then created in the electron transport chain. The end products are ATP, CO2, and water. Oxygen is an electron acceptor at the end.
53
What are the steps of anaerobic respiration?
It starts with glycolysis where a glucose molecule is broken down into pyruvate. If there is insufficient oxygen for aerobic respiration, pyruvate is converted into lactate
54
What is steady state locomotion?
“Cruising”/”Routine” behavior: Fueled aerobically, primarily using red muscle fibers. It can be sustained for long periods of time.
E.g. Fish swimming around the reef or
Humans going for a light jog
55
What is unsteady state locomotion?
Sudden, intense exertion: Fueled anaerobically, primarily utilizing white muscle fibers. It causes lactate accumulation so cannot be sustained for a long period of time
This can lead to fatigue
56
How do birds save energy during locomotion?
Social behaviours such as flying in a v formation where the following birds take advantage of air upwash/ downwash that is produced by the leading bird´s wing pattern (creating greater aerodynamic efficiency)
57
How do schooling fish save energy during locomotion?
Fish take advantage of eddies produced by leading fish (creating greater hydrodynamic efficiency)
58
What is metabolic rate?
The rate at which an animal consumes energy.
59
What factors influence metabolic rate?
*Intensity of physical activity
*Temperature of the environment
*Diet
*Age
*Weight
*Hormones
60
What is specific dynamic action (SDA)?
Increase in metabolic rate caused by food ingestion
61
What is a requirement of measuring standard metabolic rate (SMR)
Animals must be fasted prior to experimentation to avoid variability associated with SDA. They are in a postabsorptive state
62
What is the relationship between metabolic rate and body size?
Larger animals in general have high absolute metabolic rate than smaller animals. However, this increase in metabolic rate is slower than linear (1:1)
63
What is hypoxia?
Episodes of low dissolved oxygen following natural or anthropogenic factors. Oxygen solubility declines at warmer temperatures, so hypoxic events exacerbated by climate change
64
What techniques do marine organisms use to cope with hypoxia
*Enhance oxygen uptake, transport, and delivery
*Rely more heavily on anaerobic metabolism
*Depress their metabolic needs for lower reliance on aerobic metabolism
65
What methods are used to measure metabolic rate?
*Direct calorimetry
*Indirect calorimetry
*Respirometry
*Field metabolic rate
66
What is direct calorimetry?
It measures heat production. It can measure both aerobic and anaerobic metabolism.
It is the most accurate method but is technically and logistically difficult, and expensive
67
What is indirect calorimetry?
It measures the chemical energy content of the organic matter that enters (i.e. food) and leaves an animal´s body (i.e. urine and feces) as a proxy for metabolism.
Uses a technique called a bomb calorimeter, which measures the energy in organic materials, by burning the materials under pure oxygen conditions, and measuring the heat released
68
What is respirometry?
Measures an animal´s rate of respiratory gas exchange, particularly oxygen consumption, as a proxy for aerobic metabolism
69
What is field metabolic rate measurement?
Metabolic rate is measured in a free-roaming animal. Biologgers can be used to measure movement and heart rate.
70
What medium, air or water has a higher concentration of O2?
The amount of O2 is dramatically lower in water than air because it depends on the solubility of O2 in water, and O2 is not particularly soluble. Water is 800x denser than air therefore greater mechanical work is required to move across exchange surfaces
71
What medium, freshwater or seawater has a higher concentration of O2?
Freshwater as warmer, more saline water has lower solubility as less O2 dissolves
72
What is the relationship between habitat mediums and movement of fluid in organisms?
Because of waters greater density and viscosity, water-breathing animals must generally expend more energy than air-breathing ones to move a given volume of fluid through their respiratory passages
73
Why are there no fully homeothermic (warm-blooded) water-breathers?
Heat capacity water is x3000 that of air. For the same amount of O2 taken up, a water breather is exposing itself to a heat sink x90,000 greater than for air breathers so there are none.
74
What are the two mechanisms of gas exchange
*Diffusion
*Convection (ventilation or circulation)
75
What is a dual/bimodal breather?
They can breathe air or water and often have at least two respiratory structures
76
What are the 3 types of specialised breathing structures?
*Lungs
*External gills
*Internal gills
77
What is Fick's law of diffusion?
It determines the rate at which diffusion will occour. The rate of diffusion is proportional to both the surface area and concentration difference and is inversely proportional to the thickness of the membrane
78
How can marine organisms speed up diffusion?
They can use countercurrent exchange rather then cocurrent as the blood reaches a higher O2 partial pressure because blood exchanges with fresh medium (water) just before leaving the gas-exchange membrane
79
What is buccal-opercular pumping?
In bottom dwelling sharks and rays there are well- developed spiracles that allow water to be drawn into the buccal cavity and then forced over the gills. Spiracles sustain mouth-bypassing ventilatory flow to the gills when the subterminal mouth is obstructed by substrate or engaged in prey manipulation
80
How do rams ventilate?
When swimming fast, they hold their mouth open and flow from forward motion ventilates gills. This has a lower metabolic cost of ventilation
81
What are some adaptations to improve efficiency of gas exchange?
*maximizing surface area:volume ratio
*Gill and lung structures
*Circulatory systems
82
What is feeding?
gathering and ingestion of food
83
What are autotrophs?
They are able to make their own food and energy from chemicals in their environment
84
What are heterotrophs?
They must obtain nutrients from other plants or animals for energy and nutrients.
85
What is the relationship between food web length and energy?
Short food chains deplete less energy prior to consumption, compared to long food chains.
86
What are small particle feeding methods?
*Suspension (filter) feeding: consumption of material suspended in water
*Deposit feeding: Ingestion of living and non-living organic matter
87
What is large particle feeding methods?
*Herbivory: Ingestion of living algal or plant material
*Predation: Ingestion of animal material
88
What is fluid feeding methods?
*Piercing and sucking of plant/animal juices
*Direct uptake of dissolved organic matter (DOM)
*Gain of sugars from symbionts
89
What is the feeding method of porifera?
They are filter feeders. They feed on very fine plankton and have choanocyts which move flagella to draw in water through pores
90
How is muciciliary used in filter feeding?
Motile cilia and mucus can be used to capture food particles of the appropriate size.
91
What is the feeding method of Amphiuridae spp. - brittle stars?
They are filter feeders. They feed by holding their arms into the water column and trapping particles in flowing water. Particles are moved to the mouth using groove on their oral side. In stagnant water they switch to deposit feeding.
92
How is setae used in filter feeding?
They are found o n appendages and used to collect food particles which they transfer to their mouth for ingestion.
93
What is the feeding method of baleen whales?
They are filter feeders. They have two sets of baleen plates made of keratin and a thick fibrous mat which sieves food particles from the water.
94
What is the feeding method of basking sharks?
They swim with their mouth continuously open to feed on zooplankton. Gill rakers trap and filter out plankton
95
How do deposit feeders and detritivores feed?
They consume large amounts of organic matter within sediments. They are vital for the regeneration of nutrients and enhance benthic productivity
96
How are radula use in feeding?
They are used to scrape algae off rocks or flesh off dead organisms
97
How is Aristotle's lantern
used in feeding?
It is specific to sea urchins which are herbivores. It is a muscular teeth like system which allows urchins to scrape algae off rocks for digestion
98
How do predators use hunting behaviour to feed?
A lot of species have a target prey and can change their hunting techniques depending on the species of prey. E.g. whales/orcas hunt in pods and use wave washing to push seals off of ice and dolphins hunt in pods to trap fish with their tales or mud nets.
99
How do predators use a specialised radula to feed?
Drill snails have a radula that can cut holes through shell and then either sucks out living tissue or injects venom to paralyze their prey
100
How are nematocysts used in predator feeding?
They are only found in cnidaria which dont have a hard shell so use the nematocyst for protection. It is a coiled, barbed thread that quickly turns outward and often contains venom. They can be used for both prey capture and defense.
101
How do sea turtles feed?
They are both herbivores and carnivores and have a different beak shape depending on what they feed on.
102
What is photosynthetic symbiosis?
Endosymbiotic algae produce nutrients through photosynthesis which can be passed on to the organism e.g. coral. Also, the coral emits waste products which is consumed by endosymbiotic algae
103
What is chemosynthetic symbiosis?
E.g. hydrothermal vent worms which get sulfide from vent fluids which they use for energy
104
What is digestion?
The breakdown of food molecules by enzyme action into smaller chemical components that an animal is capable of distributing to the tissues of its body.
105
What is intracellular digestion?
Organisms have a gastrovascular cavity which only has one opening which serves as both mouth and anus. Food particles engulfed by cells lining the gastrovascular cavity and are broken down in the cytoplasm. Most soft bodied animals use intracellular digestion
106
What is extracellular digestion?
Digestion occurs in an extracellular body cavity, such as the lumen of the stomach or intestines. The alimentary canal is a digestive tract with a mouth at one end and an anus at the other. Food is ingested in through the the mouth and transported by muscular contraction, passes to the gizzard where it is churned and digested. It then passes through the intestine and nutrients are absorbed. The material that cannot be digested is eliminated as feces through the anus.
107
What organisms can use both intracellular and extracellular digestion?
Flatworms and cnidarians
108
What is the gut anatomy?
*Foregut
*Midgut
*Hindgut
109
What is the anatomy of the forgut?
*buccal cavity - which contains saliva with enzymes to start digestion
*Pharynx - pumps food to the gut
*Esophagus - carries food to the stomach or crop for storage
110
What is the anatomy of the midgut?
*Stomach - ph between 1.5-2.5 which is acidic so allows for chemical breakdown of food. It can also expand up to 20x size for food store
*Secretory/absorptive caeca - Production of digestive enzymes and absorption of digested food
*Intestine - both intracellular and extracellular digestion and contains villi to increase SA for nutrient absorption
111
What is the anatomy of the hindgut?
*Rectum - Selective reabsorption of water and salts from food
Stores feces until it is eliminated
112
What are the different types of meal processing?
*Batch reactor
*Continuous-flow reactor without mixing
*Continuous flow reactor with mixing
113
What is batch reactor meal processing?
Each meal is processed before the next meal enters. E.g. jellyfish and coral
114
What is continuous-flow reactor without mixing meal processing?
Meals line up, so they don’t mix, but each meal processed for longer than in batch- reactor
115
What is continuous flow reactor with mixing?
New meals mix with meals that have already undergone some processing
116
Why have 25% of fish species lost their through gut/stomach?
They have lost the gene for the gastric proton pump (enzyme acidifies stomach) and for pepsinogens (enzyme breaks down proteins). It is thought to be partly due to their diet. Many fish eat shellfish and coral which is rich in CaCO3 which neutralizes acids in the stomach. The gastric proton pump requires a lot of energy to create stomach enzymes so is useless and an energy waste if it is just neutralised
117
What are the pathways in a 2-phase digestive system?
*rapid intestinal pathway
*slower, glandular pathway
118
What is the rapid intestinal pathway?
Uses primary extracellular digestion. The pathway is generally less efficient in assimilating many types of carbon
119
What is the slower glandular pathway?
It primarily uses intracellular digestion. You are able to assimilate C from bacteria but this also enhances the assimilation of metals which are toxic.
120
Why do some herbivorous fish have gut microbes?
Algae is not easy to digest as it is made up of long chains of polysaccharides which have to be broken down to digest. Not all herbivorous fish have all the enzymes to break down each type of algae. They have microbes which have evolved the enzymes needed to break down the algae they digest
121
Where does photosynthesis occour?
Photosynthesis occurs in the chloroplast which are mainly found in the leaves of plant. They have have spherical shape and large surface area to absorb light. They contain chlorophyll which gives plant their green colour. They also contain thylakoids which contain primary pigment reaction centres (e.g.chlorophyll a) and light harvesting complexs
122
What are phycobiliproteins?
They absorb sunlight and pass it on to chlorophyll, eventually in the form of red light. The phycobiliproteins absorb green light, each phycobiliprotein molecule the light passes through absorbs one light color until it is red, it passes through 3 molecules.
123
What ere the 3 phycobiliprotein molecules?
*C-phycoerythrin (CPE) absorbs green
*C-phycocyanin (CPC) absorbs orange-red
*Allophycocyanin (APC) absorbs red
124
What is light dependent photosynthesis?
During the light dependent stage light energy is absorbed by chloroplast pigments and used to synthesis ATP and reduced NADP, taking place in the thylakoid membrane. It converts light energy into chemical energy. The stages are photolysis, cyclic photophosphorylation and non-cyclic photophosphorylation
125
What are the steps of photolysis?
*PSII absorbs photons of light and a pair of electrons are excited and leave.
* ½ O2 is produced which can be used for respiration
*2H+ is produced and released, moving towards NADP reductase
126
What are the steps of cyclic photophosphorylation?
*The excited electrons are captured by an electron carrier
*They release energy by making ATP
*The electrons arrive at PSI which absorbs photons of light, exciting the electrons again
*If the plant requires more energy the electrons return to the electron carriers, producing more ATP
127
What are the steps of non-cyclic photophosphorylation?
*The electrons travel to NADP reductase
*2H+ from photolysis in PSII also travel to the NADP reductase, having a;lready passed through ATP synthase producing ATP
*The electrons and protons produce reduced NADP
128
What are the final outputs of light dependent photosynthesis?
Final outputs are oxygen, NADPH and ATP
129
What is light independent photosynthesis?
During the light independent stage ATP and reduced NADP are used to reduce carbon dioxide to sugar, taking place in the stroma. The stages are carboxylation, reduction and regeneration.
130
What are the steps of carboxylation?
*Carbon dioxide and RUBP reacts with the enzyme RuBisCO in order to produce 6C.
*6C is unstable so breaks down to form 2GP.
131
What are the steps of reduction?
*The 2 GP are reduced into 2 TP
*This requires energy in the form of ATP from the light dependent stage which forms 2 ADP + pi
*And 2 reduced NADP for hydrogen which forms 2 NADP
132
What are the steps of regeneration?
*5 out of6 TP molecules are reduced to form RUBP which requires energy in the form of ATP which forms ADP +pi
*The 1 out of 6 TP molecule leaves
133
What are the 3 different types of plant photosynthesis?
*C3
*C4
*CAM
134
What are C3 plants?
C3 plants only use the Calvin cycle. This represents 95% of plants. Rubisco utilise O2 instead of CO2 which is not good
135
What are C4 plants?
C4 plants represent just 1% of plants.They have an adaptation to reduce photorespiration. They separate their light reactions and Calvin cycle into different cells so they can fix C in high temps.
136
What are CAM plants?
CAM plants occour in aquatic environments where photosynthesis is limited by carbon. 2 systems are separated by time not space (cells). Have open stomates at night to take in CO2 and store maleate and then fix CO2 in the day by the Calvin cycle.
137
What is special about seagrass?
They are the only flowering plants that can live underwater. They are well adapted as they can live in various environments e.g. both tropical and polar regions. Distribution affected by temperature, salinity, waves, current, depth and day length (light), and substrate
The depth range is mainly controlled by the availability of light for photosynthesis. They are the main diet of green turtles and dugongs
and provide a habitat for smaller marine organisms e.g. prawns and fish
138
Why are seagrass ecological engineers?
They are - able to change conditions around them to suit their own needs.
*Roots can support coastline by trapping and stabilizing the sediment which reduces erosion
*Can help in nutrient poor environments by transferring nutrients from the seafloor into the water column with their roots and leaves
139
What are light adaptations of macroalgae?
*They demonstrate dynamic photoinhibition at high irradiance, or high UV to prevent damage by the accumulation of oxygen radicals through excessive photosynthesis.
* brown kelps continue growth at 0.6-1.2% of surface light
*deep- grown red algae can survive at an absolute minimum light minimum of 0.001 – 0.05%
*Different arrangements of chloroplast means a different absorption of irradiance and allows for self-shading to stop damage from the light
140
What are nutrient uptake adaptations of macroalgae?
Fast growing species are successful in eutrophic systems, whilst slow-growing species persist in oligotrophic coastal waters
141
What is special about kelp?
They help to shade the water column. Kelp are able to change their morphology depending on the wave exposure they are found in
to help shade different habitats
142
What is biomineralisation?
The process by which mineral crystals are deposited in the matrix of living organisms
E.g. shells of invertebrates
143
What is the evolution of biomineralisation?
Biomineralized structures evolve and diversify when the energetic cost of biomineral production is less than the expense of producing an equivalent organic structure. Organisms used whichever form of calcium carbonate was more stable in the water column at the point in time when they became biomineralized
144
What is organomineralization?
It is the process of mineral formation mediated by organic matter e.g. excretion or dead organisms
145
What is biologically induced mineralization?
Metabolic activity of microbes (e.g., bacteria) produces chemical conditions favorable for mineral formation
146
What is biologically influenced mineralization?
Chemical conditions surrounding the site of mineral formation are influenced by abiotic processes (e.g., evaporation or degassing)
147
What are the biological roles of biomineralisation?
Biomineralisation usually helps organisms to harden soft tissues
*Protective shells
*Exoskeleton (protection)
*Endoskeleton (support)
148
What are the different compounds used for biomineralisation?
*Phosphates
*Silicates (glass/opal)
*Carbonates
*Iron minerals
*Pyrite and gregite
149
How are phosphates used in biomineralisation?
Hydroxyapatite – primary constituent of bone, teeth, and fish scales
150
How are silicates used in biomineralisation?
*Silification
*Frustules
*Sponge spicules
151
How are carbonates used in biomineralisation?
*Calcite in coccolithophores and foraminifera
*Aragonite in corals
152
How are iron minerals used in biomineralisation?
*Magnetite (chitons) *geothite (limpets)
*Teeth of radula that are used for scraping hard substrates
153
How are pyrite and gregite used in biomineralisation?
Gastropod mollusks living close to hydrothermal vents reinforce carbonate shells
154
What is biogenic calcification?
The process by which marine organisms form calcium carbonate. When the saturation state is high, organisms can extract the calcium and carbonate ions from the seawater and form solid crystals of calcium carbonate
155
What are the different aragonite calcification states?
*When the aragonite saturation state is >1 there is supersaturation.
*When it is <1 there is undersaturation
156
What is biomineralisation in mollusks?
Mollusks are 95-99% calcium carbonate. They have a fracture toughness 3000x crystals by usisng specialised proteins.
157
What is nacre?
Found in mollusks and known as the mother of pearl, it is a strong, resilient, inner cell layer. it has hexagonal platelets of aragonite in lamina. It defends soft tissues against parasites by enclosing them in layers (encystation)
158
What is biomineralisation in crustaceans?
It creates a hard outer shell which is a network of chitin-protein fibers with CaCO3 within. As they grow they shed their exoskeleton and reabsorb its minerals to help make the new shell.
159
What is the impact of climate change on marine calcifiers?
CO2 causes more carbonic acid to form and so there are more free hydrogen ions reducing the number of smaller marine calcifiers. Organisms which use calcite are more beneficial than organisms which use aragonite calcium as aragonite is more soluble than calcite
160
How does energy flow through organisms?
Energy can be stored in organisms as carbohydrates, lipids or proteins. Energy can be lost through excretion, mechanical work, respiration or reproduction. Due to inefficiencies in energy conversions, some energy is lost in heat at every step of the energy cascade.
161
How is energy stored as proteins?
*Enzyme proteins speed and regulate biochemical reactions.
*Muscle proteins are responsible for locomotion.
*Structural proteins (e.g. collagen) determine structural properties of tissues
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How is energy stored as carbohydrates?
*They provide structural support and shape to cells (polysaccharides like cellulose)
*They are transport compounds (monosaccharides or disaccharides)
*They are storage compounds (polysaccharides like starch and glycogen)
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How is energy stored as total lipids?
They are principle components of cells and intracellular membranes (e.g.phospholipids and cholesterol). they can be staurated (no double bonds) or unsaturated (at least one double bond).
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What is stress?
A factor that shifts biological processes from their homeostatic optimum
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How is blubber used in energy storage?
Blubber is a lipid-rich hypodermis found in marine mammals. It has 5 functions:
*Insulation
*Buoyancy
*Body shape
*Biological spring (decreases energy required for locomotion)
*Energy stores
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How is global warming impacting coral enegy?
Elevated temperatures leads to bleaching where there is loss of endosymbionts from coral tissues. The loss of algae reduces their energy level. They have to adapt to have enogh energy by increase feeding, decrease metabolism, decrease calcification or break down energy reserves
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What caused a rise in aquaculture?
Population expansion paired with increased food consumption per capita
Both capture fisheries and aquaculture production has increased, however aquaculture production is beginning to overtake
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How is biotechnology being paired with invertebrate immune function?
Organisms, such as crabs, are bled for their serum (clotted plasma)They then extract Limulus haemolymph which have a strong response to bacteria and pathogens an it can be used for antibiotics or to test sterility
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What are the roles of immune systems?
*Surveillance (recognises non-self)
*Recognition
*Response
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What are the two main types of immune response?
*Innante immunity
*Aquired immunity
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What organisms use each type of immune response?
*Invertebrates use innate immunity
*Vertebrates use both innate and acquired immunity
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What are the different layers of immune defences?
*1st layer = barrier immunity
*2nd layer = innate immunity
*3rd layer = adaptive immunity
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What are the characteristics of the 1st layer of defence?
The 1st layer is barrier immunity e.g. skin and mucous. This barrier stops most pathogen entry. (It is non-specific)
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What are the characteristics of the 2nd layer of defence?
The 2nd layer is innate immunity consisting of roaming scavenger cells such as phagocytes which engulf pathogens and debris. (This is non-specific)
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What are characteristics of the 3rd layer of defence?
The final layer is the adaptive immune system, which consists of lymphocytes that adapt to the structure of pathogens to eliminate them efficiently. (It is specific)
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What are superoxides?
Superoxides are non-specific and break down cell walls through a series of reactions. The negative is they are non-specific so can break down host cells
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What is INOS-NO / the nitric oxide pathway?
It uses arginine to cause oxidative damage to bacteria
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What id PDV?
Phocine distemper virus (PDV) is a single stranded RNA virus in the same family as measles. There was a major outbreak in 1988 with 18000 deaths of harbour seals and there have been more outbreaks until 2009. Symptoms include mucus secretion, respiratory distress and diarrhoea. Harbours seals are more susceptible to PDV than grey seals as North Sea pollution suppressed their immune system so they were less able to fight the virus.
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What have Chordata studies revealed in relation to immunology?
Studies in tunicates have shown well- developed self and non-self recognition;
If you put two chordate colonies together you will see the production of immune effector molecules and the colonies attack each other as non-self
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What are the 3 types of adaptive immune response.
*Antibodies and the humoral immune response
*cell-mediated immune response
*memory response
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What are APC?
Antigen presenting cells. They present antigens from engulfed pathogens to activate other immune system cells e.g. macrophages
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What are T helper cells?
They release interlukins (a type of cytokine) that stimulates B cells to develop and phagocytosis
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What are the steps of a cell mediated response?
*Macrophages engulf pathogens by phagocytosis and present the antigens on their surface
*Specific T helper cells with a. Receptor complementary to the antigen binds to the macrophage. The T helper cells then produce interlukins which stimulates mitosis and differentiation of T cells
*The new T cells may become more T helper cells, T killer, T memory or T regulatory cells.
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What are the steps of a humoral response?
*T helper cells with a receptor complementary to the antigen bind to an antigen presenting cell
*The T helper cells release cytokines, stimulating clonal expansion of B lymphocytes
*B cells differentiate into plasma cells
*Plasma cells secrete antibodies with a complementary region to the antigen
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What are antibodies?
They are proteins that bind to antigens and destroy them
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What is the structure of an antibody?
They have 4 polypeptide chains. 2 light chains and 2 heavy chains held together by disulphide bridges. The biding site on the variable region of the light chain has a specific tertiary structure complementary to an antigen.
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What are the different types of antibodies?
*IgA
*IgD
*IgE
*IgG
*IgM
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Where is each antibody found in the body?
Every antibody is expressed in the lymph apart from IgA which is found throughout the gut.
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What is the function of each antibody?
*IgA - forms dimmers
*IgD - unknown function
*IgE - responsible for allergies
*IgG - 4 subclasses and responsible for opsonisation and neutralisation
*IgM - produced upon 1st antigen invasion and is the main antibody expressed
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How is receptor diversity generated?
"Random" recombination of gene segments generates a combination of receptor varieties.
Because it is made from a germ-line they can be inherited by offspring
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What is affinity maturation?
High affinity binding between an antigen and antibody which produces a plasma cell which sectretes more antibodies to attach to any other present antigens. This can produce memory cells. If there is no cell binding there is eventually apoptosis/cell death of the unhelpful receptor
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How are effective receptors selected?
Activated B-cells proliferate, producing mutated clones, which are subject to selection via epitope affinities.Clones with the highest affinity for the pathogenic epitopes survive and differentiate to become plasma or memory cells.
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What is tolerance of self?
T-cells undergo central toleration via clonal deletion in the thymus. If any antibodies bind to self-proteins they are programmed to undergo cell death to stop immune responses against ourselves e.g.allergy responses which are bad.
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what is secondary immunity?
During the secondary response, the antibody concentration in the blood takes a much shorter period of time to increase and is higher than after the vaccination or first infection due to memory cells
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What are vaccines?
They contain an attenuated form of antigens causing artificial active immunity.
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How do unicellular organisms move?
By changing shape using sliding elements in the cytoskelton. Some can also swim using cilia or flagellae.
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What are some persistence of flagellae?
Choanocytes and spermatozoa
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What are some organisms that use cilia for movement
Turbellarians and gastropods
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What is the structure of cilia?
They are a cylindrical array of 9 filaments within a complete microtubule . Cross-bridges of the motor protein dynein extend from the complete microtubule of one filament to the partial microtubule of the adjacent filament. It is also sheathed in the plasma membrane.
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What are muscles attached to?
In vertebrates muscles attach to a bony internal skeleton. In hard bodied invertebrates the muscles are attached to a rigid exoskeleton. In soft bodied invertebrates the muscles act on a hydrostatic skeleton ( a fluid-filled body compartment)
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what are the steps of the sliding filament theory?
*calcium ions are released from the sarceloma and bind to troponin
*Troponin displaces the tropomyosin exposing the myosin-binding site
*Myosin bulbous heads attach to actin and there is a power stroke causing the heads to slide
*ATP binds to myosin heads, causing it to become detached from the actin
*Hydrolysis of ATP provides energy for myosin heads to re-cock
*Calcium ions detatch from troponin and it reverts to original shape
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How do metazoans carry out swimming for movement?
*Cilia and flagellae
*wave-like undulations
*fluid propulsion
*use of flattened appendages
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How do different organisms move through sediment?
Hard bodied diggers or soft bodied burrowers.
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How do nephtys move through sediment?
When the ventral coelomic muscle relaxes, the pharynx is moved out of the body and can absorb sediment to move further down
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What forces can affect movement in water?
*Inertial forces must be overcome to start moving
*to keep moving, animals must overcome friction, drag, and gravity, which all tend to slow or stop motion.
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What is the Reynolds’ Number (Re)?
It explains the drag effects on the fluid flow over an animal. Small organisms don’t create turbulence they create laminar flow. Larger organisms create turbulent flow, this is advantageous as the turbulance can help them move so muscle contraction does not have to be constant unlike in smaller organisms.
If Re < 10 they use laminar flow. If Re is large they use turbulent flow
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What is the difference between laminar and turbulent flow?
Laminar flow organisms are mainly affected by viscous drag that retards forward progress. The organisms must continuously expend energy to keep moving. Turbulent flow organisms can use streamlining to stop low pressure
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What is Gray’s Paradox?
The apparent power output of fast swimming fish was insufficient for them to swim at the fast speeds that were easily observed at in situ. They have evolved adaptations to improve their hydrodynamic efficiencies
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How does frictional drag effect organisms?
Frictional drag is the most important source of drag in fast-swimming fish, such as sharks. It is caused by the friction created between the skin and the boundary layer. It cash be reduce if the boundary layer maintains turbulent flow.
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What adaptations do sharks have to swim fast?
All fast swimming sharks have sharp-edged riblets on their skin created by the denticles in their skin. This allows them to absorb some turbulence and surface vortices to break away easily.
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How do sessile organisms stay put?
The shape and ribbing of the base plate increases the adhesion of a protein glue that is coded for the same gene that contributes to clotting agents associated with mammalian erythrocytes factor XIII
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Why do animals move?
*Food
*Reproduction
*Predator avoidance
*Environmental conditions
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What is the movement ecology paradigm?
*the internal state (why move?)
*motion (how to move?)
*navigation (when and where to move?)
*external factors affecting movement
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What is movement?
A physical displacement over time.
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What is the size range of motile organisms?
Dinoflagellates (5 µm - nanoplankton)
Blue whale (130 tons)
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What is the speed range of motile organisms?
From as slow as plankton (passive drifting) and dinoflagellates (0.0002124 km/h)
To as fast as blue marlin (75 km/h)
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What is the basic relationship between size and speed?
We expect bigger animals to be faster – a power law* relationship.
Bigger animals have longer limbers to move faster
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Why is the power law relationship not perfectly linear?
Animals are limited in their time for maximum acceleration because of restrictions on the quickly - available energy. Larger animals can take long to accelerate as their bodies require a lot of energy to maintain fast speeds.
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What are different techniques of studying movement?
Biologgers are animal-attached remote sensing and can measure environmental, physiological and movement parameters.
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What are the different types of geographic location tags?
*GPS
*Argos satellite (PTT)
*Geolocator (GLS)
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How is movement measured tag-less?
The animals must be captures. Can be favourable if animals are small so tags may be too big or heavy. They are also expensive.
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What are different types of movement patterns?
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223
What do crocodiles use breath-hold diving for?
*predator avoidance
*foraging / hunting
*social interaction (mating)
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What dive response do crocodiles use in preparation for a dive?
brachycardia (slowing of heart rate) + peripheral vasoconstriction (constriction of peripheral circulatory system) to reduce the oxygen demand
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What is special about crocodile hearts?
They have a shunt between two circulatory systems allowing redistribution of blood/oxygen. They may redistribute flow to brain & heart in dives
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What do marine iguanas feed on and how?
Feed primarily on marine algae. Smaller individuals forage in intertidal; larger animals dive subtidally
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What is the max depth of marine iguanas?
30m
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What is the max depth of sea snakes?
250m
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What do green sea turtles dive for?
During migration they can dive for up to 20 m for 30 mins. However they normally just use shallower doves for feeding on seagrass.They ca also submerge for hours at rest for sleeping
230
What do green sea turtles dive for?
During migration they can dive for up to 20 m for 30 mins. However they normally just use shallower doves for feeding on seagrass.They ca also submerge for hours at rest for sleeping
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What do leatherback turtles dive for?
Their deepest dives are more than 1200m and can last longer than 60 mins during migration. They can also dive at shallower depths to forage for deep patches of gelatinous zooplankton
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What is the max depth of northern gannets?
34m (mean depth 19.7m)
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What is the max depth of emperor penguins?
564 m (max duration 32.2 mins)
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What is the average dive of sirenians (e.g. dungeons and manatees)?
<5m and 2-3 mins
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What is the average dive of sea otters?
40 m and 4 mins
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What is the average dive of hooded seals?
>1000m and >60 mins
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What is the average dive of southern elephant seals?
2000m and 120 mins
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What is the average depth of curvier’s beaked whales vs the max recorded?
>1000m for 1 hour. Max 2992m for 137.5 mins
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What are human breath-hold diving records?
*No weights or fins: 102 metres
*Weighted descent, air-bag ascent: 253 metres
*Static apnea: 11 mins 54 secs
*Static apnea after pure O2: 24 mins 11 secs
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What are human ambient-pressure diving records?
*Deepest single SCUBA dive: 332 m
* Deepest open-ocean saturation dive: 534 m
*Deepest simulated dive: 701 m
241
What are the 4 physiological challenges from breathing gas under pressure?
*oxygen toxicity
*safe decompression of saturated tissues
*inert gas narcosis
* high-pressure nervous syndrome
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What is oxygen toxicity?
O2 molecules are not toxic but in other forms such as oxygen radicals it is. It can lead to problems with the brain and CNS such as seizures.
243
How can you solve oxygen toxicity?
use lower % O2 in gas mix for deep phase of dive
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What is safe decompression in saturated tissues?
Inert gases in the air dissolve in blood and body fluids. Breathing gas under pressure accumulates more of them in solution. When ascending pressure reduces causes gas to come out of the solution which can cause decompression sickness / the bends from bubbles.
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What is inert gas narcosis?
The main inert gas in air is 78% N2 which can have a narcotic effect at high pressure. It dissolves in cell membranes, disrupting normal signalling.
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How can you solve inert gas narcosis?
Use a different diluent gas e.g. helium. But helium still has narcotic effects at greater depths
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What is high-pressure nervous syndrome (HPNS)?
HPNS results from effects of pressure on central nervous system
Symptoms include tremors, eye twitch, headaches, fatigue. Effects are separate from inert gas narcosis, and “opposite”
(overexcitation of nervous responses, rather than narcosis)
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How can you solve HPNS?
Slow compression can reduce, but not avoid, the problem. Also, some inert gas narcosis could be used to offset HPNS to some extent
249
What is trimix?
It is used for deep dives and is a mix of gases using the assumption some inert gas narcosis can be used to offset HPNS to some extent.
O2, He and a small amount of N2
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What is aerobic dive limit?
The amount of time a breath-hold animal can dive before depletion of oxygen stores (& build-up of lactate)
251
What are different oxygen stores in animals?
*Lungs (as gas)
*Blood (as O2 bound to haemoglobin)
*Tissues (e.g. as O2 bound to myoglobin in muscles)
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Why does using the lungs as the primary oxygen store (like in humans) cause problems when diving?
* variable buoyancy as lungs become compressed during dive
* absorption of pressurized gas into blood during dive
*To overcome this most big organisms collapse their lungs when deep diving
253
What are different methods for investigating deep-dive physiology?
*Looking at traditional anatomy
*Immersion experiments in labs
*Tagging individuals in situ
*Comparative genomics and trascriptomics on blood samples
254
What are adaptations of hooded seals for diving?
*Exhale before
*Alveoli collapse
* Lung surfactants have anti-adhesive function, enabling reinflation
*Large blood volume for body size
*Large spleen releases high hematocrit blood
*can store 6x oxygen in myoglobin then humans
*Peripheral vasoconstriction prioritises blood flow to brain & heart (muscles run on local myoglobin stores, then anaerobic respiration)
*Brachycardia
*Brain cooled from front flipper blood
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What are adaptations of northern elephant seals for diving?
*High blood volume and haemoglobin concentration
* Peripheral circulation shuts off during dives
*High carbon monoxide levels in haemoglobin
256
What are adaptations of penguins for diving?
*Penguin bones lack air spaces which reduces buoyancy and reserves carbonate for lactate buffering
*collapese lungs
*relaese air bubbles in plumage before jumping ashore to reduce drag
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What are adaptations of leatherback turtles for diving?
Ectotherms by having large size to reduce SA:V and insulating fat layers
258
What are the “ultimate breath holders?
Treachery’s scripts. They can hold their breath for months during winter hibernation when ice layer forms above a river. They are a freshwater species. They reduce brain metabolism to 10-15% during hibernation. They also have a lot of heat-shock proteins (HSP) and superoxide dismutase (SOD) which mop up reactive forms of oxygen
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How do cetaceans (Whales/dolphins) protect the brain from pressure surges in downstrokes?
Vascular plexus protects cetacean brains from spikes in blood pressure while swimming during dives
Fluke-swimming creates pressure waves in circulatory system; series of retia effectively dampen these out in flow to the brain
260
What are odontocetes?
Toothed whales which are hunters
261
How do odontocetes create sound?
They create sound for communication and echo locating sound. Their air is stored in nasal cavities and passes over "phonic lips". They use different vocal registers e.g. M1 and M2 for normal sound and M0 for vocal fry
262
What are adaptations of sperm whales for diving?
*Spermaceti organs reduce buoyancy
*wax solidifies in cold water so is less dense, metabolic heat then melts the wax to help ascent
263
What are the findings to suggest whales can dive deeper than records?
Marks on Pacific seafloor at 4200 m similar to those known from beaked whales suggest possibility
Beaked whales dive deep to feed on deeper-dwelling mature squid (while other toothed whales feed on shallower juviniles).
