ASVAB CampEcology flashcards
8 cards with the formulas, rules and traps from this lesson. Answer in your head, then flip to check.
Rule · 1/8
Population, community or ecosystem: how do you tell them apart?
Count species. One species in an area is a population; several species together form a community; a community plus its nonliving conditions (water, light, soil) is an ecosystem.
Common trap · 2/8
Which way does an arrow point in a food chain or food web?
From the food to the eater, showing where energy and matter go. Read each arrow as 'is eaten by'. Grass to rabbit means the rabbit eats the grass.
Rule · 3/8
How do you identify the tertiary consumer in a food chain?
Start at the producer and count feeding steps: primary consumers eat producers, secondary eat primary, tertiary eat secondary. Do not just pick the top predator.
Formula · 4/8
Energy reaching higher trophic levels under the 10 percent model?
Each level gets about one-tenth of the level below: move the decimal one place left per step. 20,000 kcal of producers gives 2,000, then 200, then 20 kcal. Use a different percentage if the question states one.
Fact · 5/8
How do matter and energy differ in the way they move through an ecosystem?
Matter (carbon, nitrogen, phosphorus) is recycled again and again. Energy flows one way: in as sunlight, up the food chain, out as heat that producers cannot reuse.
Formula · 6/8
How do you calculate the net change in a population's size?
, where B is births, I immigrants, D deaths and E emigrants over the same period. Example: 400 elk with 60 B, 12 I, 45 D, 7 E end at 420.
Term · 7/8
Mutualism, commensalism and parasitism: what are the effects on each partner?
Mutualism: both benefit (+/+), like bees and flowers. Commensalism: one benefits, the other unaffected (+/0), like barnacles on a whale. Parasitism: one benefits, the host is harmed (+/-), like a tapeworm.
Common trap · 8/8
Eutrophication versus biomagnification: what is the difference?
Eutrophication: excess nitrogen and phosphorus cause algal blooms whose decay uses up oxygen, creating dead zones. Biomagnification: a toxin such as DDT or mercury becomes more concentrated at each higher trophic level.