A cow is a predator
The instinct: predators are carnivores with teeth and claws
In ecology a predator is any organism that feeds directly on another living organism. Herbivores, carnivores and omnivores all count. Scavengers, detritivores and decomposers eat dead things, so they are not predators.
Address vs job
The instinct: habitat and niche mean the same thing
A habitat is the place, the set of conditions where an organism lives. A niche is the role the species plays in the community plus the conditions that decide where it can live. One is where it lives, the other is what it does there.
Allopatric means apart
The instinct: sympatric speciation needs a barrier too
Allopatric speciation happens when populations are geographically separated, like the Galapagos finches and the Arizona red squirrels split by desert. Sympatric speciation happens in the same area, driven by behavioral isolation.
Slide, squeeze, split
The instinct: all three selection types push traits the same way
Directional: the whole curve slides toward one extreme. Stabilizing: the middle wins, extremes get cut, the peak gets taller and thinner. Disruptive: both extremes win, the middle dies out, the curve splits into two peaks.
Know your plus and minus
The instinct: commensalism helps both, parasitism is its own weird thing
Mutualism is +/+, both win. Commensalism is +/0, one wins and the other does not care. Parasitism is +/-, one wins and one loses, and your deck counts it as a type of predation. Predation is also +/-. Competition leaves both sides worse off.
Intra is inside
The instinct: interspecific means inside one species
Intraspecific competition is members of the same species fighting over limited resources. Interspecific competition is different species fighting. Same prefix logic as intramural vs international.
Soil is the whole question
The instinct: any regrowth after a fire is primary succession
Primary succession starts on bare land where nothing lived before, no soil, pioneers like lichens and mosses build it from rock. Secondary succession happens after a disturbance but grows back from the biological legacy of the old community, soil and all.
Too much kills too
The instinct: limits only matter at the low end
Shelford's tolerance limits have a minimum and a maximum. Past either line the species cannot survive or cannot reproduce. The saguaro stops spreading north because of freezing temperatures, that is the cold end of its range doing the blocking.
The panda is the picky one
The instinct: a big range means specialist
Generalists like the black bear tolerate a wide range of conditions and foods, a broad niche. Specialists like the giant panda have a narrow niche and depend on one setup. Wide tolerance, generalist. Narrow tolerance, specialist.
The otter holds up the kelp
The instinct: a keystone species is just the biggest or most common one
A keystone species holds the community together way beyond its numbers. Sea otters eat sea urchins. Urchins eat kelp. Kelp shelters fish and seals. Take the otters out and the urchins explode, the kelp dies, and the whole neighborhood goes with it. Keystones are not always top predators anymore either.
Batesian is bluffing
The instinct: mimicry and camouflage are the same defense
Camouflage is hiding, blending into leaves and bark. Batesian mimicry is a harmless species copying the look of a poisonous or bad tasting one, so predators who learned the hard way leave it alone. One hides. The other fakes being dangerous.
Most mutations do nothing
The instinct: natural selection creates the mutations it needs
Mutations happen on their own in the DNA. Most have little effect, some hurt, and a few happen to help. Natural selection does not order mutations, it just passes on the ones that already work. The fittest reproduce more, the traits spread.
Fighting spreads them out
The instinct: competition makes populations clump together
Uniform (ordered) patterns come from competition and territoriality, everyone keeps their distance. Patchy (clustered) patterns come from grouping up for protection, help, or reproduction. Random is wherever resources and chance let individuals settle.
Two names, three domains
The instinct: the scientific name is family plus genus, and there are four domains
A binomial name uses the two most specific levels, genus plus species. Humans are Homo sapiens, corn is Zea mays. And life splits into three domains by cell structure: Bacteria, Archaea, Eukarya. The four kingdoms (animals, plants, fungi, protists) live inside Eukarya.
Gleason wins the argument
The instinct: the climax community idea is the accepted one
Cowles and Clements pictured succession as a march to a final climax community, like an organism growing up. Gleason said species are individualistic, each settles where it personally can colonize, tolerate and reproduce. Gleason's view is the one more widely held today.
Edges blend, cores stay pure
The instinct: diversity and abundance are the same measurement
Diversity is how many different species are in an area. Abundance is how many individuals of one species. And where two communities meet, edge effects blend the conditions across the border, while core habitat deep inside a patch stays free of that edge influence.
Rapid Fire
Say the answer out loud before you tap. If you have to tap to know, that one goes back on the list.
Full Mock Test
32 questions, every section of the chapter, all pulled from the deck. Tap an answer and it marks you on the spot. Run it till you hit 32 out of 32, then stop.