marine biology exam 1

benthic

associated with the seafloor

scientific method

a generalized system of observation and inference of the natural world

plankton

organisms that live suspended in water

nekton

larger animals that swim in the water column, can move against a current or in turbulent water

inference

using some premise or logic to generate a prediction of conclusions

epifauna

animals that live on the seabed surface

infauna

animals that live in the seabed surface

what is hypothesis testing?

using experiments or observations to produce an outcome that shows the hypothesis is false, most powerful when specific predictions for an experimental treatment can be contrasted with difference from a control

hypothesis

a statement that can be tested

what are the major equipment used to study the oceans?

research vessels, sampling equipment (nets, dredges, etc.), remote sensing by satellite imaging, submarines, remotely operated vehicles, autonomous underwater vehicles, scuba equipment, gps systems with video

who are the major historical figures in marine biology and why are they important?

linneaus: developed modern means of naming species, described hundreds of animal and plant species

edward forbes: naturalist on the *Beacon* (Mediterranean Sea) found that # of creatures decreased with increasing depth, azoic theory: no life below 1800 ft., different species live at different depths

michael sars: disproved azoic theory in Norwegian fjords, first plankton net

charles darwin: formed theory on development of coral reefs (reefs developed around emergent rock that was sinking)

john murray: *Challenger* expedition, circumnavigated the globe and provided 1st global perspective of ocean diversity, sampled all seas except arctic

intertidal zone

highest and lowest extent of the tides

subtidal zone

below intertidal, remainder of seabed

epipelagic zone

upper 200 m of water

mesopelagic zone

200m -1000m

bathypelagic zone

1000m - 4000m

abyssopelagic zone

4000m - 6000m

hadal environements

seabed and waters at bottom of trenches, often >6000m

salinity

grams of dissolved salts per 1000g seawater

salinity in open ocean

\~35 0/00

amplitude

height from neutral to crest of wave

wave length

distance between successive crests

spring tide

gravitational force of the sun amplifies that of the moon, maximum tidal range is acheived

coriolis effect

movement of fluids in relation to earth’s rotation beneath, results in deflections

neap tide

when sun, earth, moon form a right angle at times of quarter moon, results in minimum vertical tide range

gyres

large system of rotating ocean currents (ex: gulf stream)

estuary

body of water where freshwater source from land mixes with seawater, often results in strong salinity gradient

what affects the marginal seas?

marginal seas: restricted connections w/ open ocean + shallow depths

affected by: local climates excessively

what are some major topographic features of the sea floor?

continental shelf (1deg slope)

continental slope (2.9deg slope)

continental rise

abyssal plain

submarine canyons

oceanic ridge systems

volcanic islands

trenches

What are some major properties of seawater?

\-hydrogen bonds

\-high heat capacity: can absorb significant heat

\-high latent heat of evap: lot of energy to change to gas

\-high latent heat of melting: lot of energy to change to liquid

\-high dissolving power

\-high transparency (absorbs infrared, ultraviolet)

how does density change in seawater?

influenced by salt

increases with increasing salinity and decreasing temperature

continental drift

continents move along with spreading crust during seafloor spreading, leads to different arrangements of continents

how do waves form?

wind moves over water and sets up a series of wave patterns, which cause oscillatory water motion

how are tides formed? what is the stronger influence on them?

gravitational effects of the moon and sun, modulated by earth’s rotation and basin shape

* moon has stronger influence, closer to earth

ecology

study of interactions between organisms and their environment

inducible defenses

prey deploy defense structures when predators are present

optimal foraging theory

decision “rules” a predator should use to optimize food

diet breadth model

rule: food scace, increase breadth

food plentiful, specialize in high quality food

time in path model

rule: greater distance between patches, spend more time in given patch

parasitism

one species lives at expense of the other

mutualism

evolved association where all species benefit

commensalism

only one species benefits, other unaffected

amensilism

one is harmed, other is unaffected

polymorphism

variation that is discreetly different

phenotype

form an organism takes

fitness

relative survival and reproduction of a given genotype

adaptation

occurs when natural selection causes an evolutionary change, increased survival/performance

metapopulation

interconnected group of subpopulations

foundation species

contribute to structure of local habitat and determine physical/chemical properties

competition

2 individuals of same or different species exploit a common limiting resource

competitive displacement

one species outcompetes another for a resource

coexistence

2 species exploit different resources, process allows 2 species to exploit same resource w/out displacement

disturbance

change in environment (usually physical) that causes mortality or affects reproduction

succession

predictable order of appearance and dominance of species, usually following disturbance

top-down processes

top predators have strong effects on food webs

bottom up processes\`

changes in primary production drive changes in food web

genotype

genes that control a trait

phenotypic variation

variation explained by genetic factors+variation from environmental factors+interaction between the 2

natural selection

selection of certain traits by fitter members reproducing more frequently

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phenotypic plasticity

ability of single genotype to develop different forms, usually in response to environment

biotic vs. abiotic factors

biotic: living factors

abiotic: nonliving factors

what is the ecological hierarchy? largest → smallest

biosphere - ecosystem - community - population - organism

how are organisms distributed on a small scale? give an example

organisms have an ecological niche - range of environments over which a species is found, includes both biological and physicochemical dimensions (interacting species, water depth range, salinity range)

what are the consequences of competition?

extinction: usually local, habitat shift

coexistence: niche shift, character displacement, or evolution or shift in morphology/behavior

variable environment: unstable but can permit coexistence

why do we not see climax state in the marine environment?

major external disturbances or differences in time of year may cause major shifts from one community condition to another

* habitat shifts
* continuing disturbance
* varies widely across habitats

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what is allopatric speciation and how does it occur?

new species originate if geographic border is introduced

occurs via genetic drift when populations are separated by physical barrier and eventually can no longer interbreed

describe the various trophic levels in a typical marine community

producers → primary consumers → secondary consumers → tertiary consumers

large population → small population

high energy → low energy

primary producers: mainly photosynthetic, convert light + CO2 into sugars (autotrophs)

secondary producers: consume primary producers, herbivores (heterotrophs)

carnivores: eat herbivores

decomposers

compare and contrast competitive displacement with coexistence

similar: result of competition for the same resource (habitat, food, etc.)

different: coexistence has no displacement

compare and contrast inference competition with exploitation competition

similar: types of competition for the same resource

differences: interference → less direct (one species overgrows another, interspecific territoriality, agonistic interaction)

exploitation/scramble → more direct, one species is just “better” (one species eats a prey resource more efficiently than another)

what is the intermediate disturbance-predation hypothesis? what happens under low/med/high levels of disturbance or predation? what level promotes coexistence and higher biodiversity?

low levels of disturbance/predation: competitive dominant species takes over

intermediate levels: promotes coexistence, more species present, highest level of coexistence and biodiversity

high levels: most individuals removed, reduces total number of species

what is succession? give detailed example

predictable order of appearance and dominance of species, usually following a disturbance

early species modify unoccupied habitat, which facilitates later colonization → inevitable colonization of successively competitively superior species, following initial community

example: volcano erupts, lava melts and leaves blank are with no plants → coral is deposited and begins to grow on the rocks → continues to grow and spaw, stacks to create a reef

compare top down and bottom up food web processes. give example of each

top down: top predators have strong effects

example: apex predator is hunted to extinction, initiates a trophic cascade

bottom up: changes in primary production drive food web changes

example: large scale increase in phytoplankton productivity, allows greater food input, increases populations of apex predators

acclimation

change of function and tolerance that results in an equilibration with new conditions

regulation

maintaining consistency of a parameter inside the body

conformance

changing internal parameters to conform to environmental conditions

scope for growth

difference between the amount of energy assimilated from animal’s food and cost of metabolism

positive: energy available for growth + reproduction

negative: energy will lose weight, etc.

aerobic scope

difference between regular metabolism and maximal (active) metabolism

homeotherm

regulates body temperature (warm-blooded)

poikilotherm

temperature varies with external temperature (cold-blooded)

ectotherm

body temperature matches external temperature, metabolic heat is lost to environment

endotherm

internal temperature greater than external temperature, metabolic heat is reatained

countercurrent exchange

some heat is lost and then regained during circulation

osmosis

movement of pure water across a membrane permeable to water (movement of pure water)

diffusion

random movement of dissolved substances across a permeable membrane (movement of solute)

bioluminescence

organisms that can produce their own light

what are some examples of adaptive responses?

behavioral responses

gene regulation: activation of genes, pathways

biochemical: changes of concentrations of enzymes, ions within specific cell types

physiological: cellular changes

compare and contrast scope for growth vs. aerobic scope

same: both can impact growth and metabolism, both require excess food, increase in relation to each other

different: growth is based on food beyond cost of metabolism, aerobic is based on need of food for activity as well as other resources/factors (oxygen/temperature)

how does temperature vary in marine environments?

latitude gradient, regional differences

seasonal temperature changes

short term changes: weather changes, tidal changes

compare pros and cons of poikilotherms vs. homeotherms

homeotherms: regulation

* pros: constancy, high rate of cellular chemical reactions
* cons: heat loss

poikilotherms: conformance

* pros: no cost of keeping temperature constant and high
* cons: loss of metabolic efficiency

describe the function of glycoproteins and glycopeptides

function as antifreeze, low concentrations so no effect on osmotic pressure, bind to incipient ice crystals to prevent them from growing

how does salinity vary in the marine environment?

varies in estuaries, tide pools, melting of sea ice, rainfall, etc.

what are some habitats with potentially low oxygen?

low tidal zones, within sediment layers, in the oxygen minimum layer, seasonal hypoxic zones due to algal blooms/eutrophication etc.

what factors cause oxygen consumption to increase?

increasing body mass, activity, metabolic rate

what are the two primary retinal cells and how do each function?

rods and cones

rods: low light intensity vision, more sensitive but do not discriminate wavelengths

cones: higher resolution, color vision, function only in bright light

what are methods homeotherms use to maintain body temperature?

insulation: blubber, feathers

countercurrent heat exchange: circulating venous and arterial blood in opposite directions while vessels are in contact to reduce heat loss

what is limited in high and low latitudes in each season?

high latitudes (coldest):

* winter: survival
* summer: reproduction

lowest latitudes (warmest):

* winter: reproduction
* summer: survival

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what happens when an organism is in a hypotonic solution? hypertonic solution? isotonic solution?

hypotonic: cell swells, water is absorbed by the cell

hypertonic: cell shrinks, water is lost by the cell (absorbed by surroundings)

isotonic: cell remains same size/shape, water flow is at equlibrium

what are some mechanisms that organisms use to take up oxygen?

small/thin organisms use diffusion

fish use gills (high surface area to absorb O2)

mammals use lungs w/ enormous surface area

describe the bohr effect

lowering the pH of the blood/fluids shifts the oxygen dissociation curve to the right

* hemoglobin ability to hold oxygen decreases with decreasing pH
* pH is lower near capillaries that are starved for oxygen, CO2 is released from cells, hemoglobin releases oxygen that diffuses into the cells

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describe the eye of a fish

fish eyes use a lens/series of lenses to focus light gathered by the eye. lens consists of material of increasing density toward the center, allows lens to bend light and focus an image. fish have muscles that move the lens back and forth to adjust for focus