B4g: Decay Flashcards Preview

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Flashcards in B4g: Decay Deck (11):

Factors increasing rate of decay (4)

+microorganisms, more of them to decay other living thing more quickly

+temperature (until optimum temperature reached): microbes respire faster, will grow and reproduce faster

+oxygen: microbes can use aerobic respiration to grow and reproduce faster

+water (moist conditions): allows for material to be digested and absorbed more efficiently and increase growth and reproduction


Groups of organisms involved in decay (2) + examples

detrivitrores - e.g. earthworms, maggots, millipedes, woodlice

decomposers (mostly saprophytes) - e.g. bacteria, fungi


What does detritivores do and how

increases rate of decay by increasing SA of dead remains for decomposers to act on


What is a saprophyte

an organism that feeds on dead and decaying material by extracellular digestion


How do saprophytes feed(3)

saprophytes release enzymes onto dead animal/plant

enzymes digest dead material through extracelullar digestion

saprophytes absorb digested substances


How does canning reduce the rate of decay(2)

foods are heated to kill bacteria

foods sealed in a vacuum to prevent entry of oxygen and bacteria


How does cooling reduce the rate of decay

slow down bacterial and fungal growth and reproduction


How does freezing reduce the rate of decay

kill some bacteria and fungi and slow down their growth and reproduction(or stop it)


How does drying reduce the rate of decay

removes water so decomposers cannot carry out cell reactions, grow or reproduce


How does adding salt/sugar reduce the rate of decay(2)

decreases water concentration in the food, drawing out water from the decomposers through osmosis
-without water, they cannot carry out cell reactions, grow or reproduce


How does adding vinegar reduce the rate of decay

produce very acid conditions killing most decomposers