AP Biology Ecology Questions - ANSWERS
Chapter 35: Behavioral Adaptations to the Environment
1. What is “behavior” defined as?
Everything and animal does and how it does it.
2. What is the definition of a fixed action pattern? Give an example of one. Why might FAP’s be linked to
evolutionary success and survival?
FAP = unchangeable behavioral sequence EX baby Bird raising head, opening mouth, and cheeping for food.
They maximize fitness to the point that genes for variants of that behavior are lost – must get right on first try
if it is to stay alive.
3. Animal behavior is a sum total of one’s genes (nature) and one’s environment (nurture).
4. Define learning. Describe habituation, imprinting, spatial learning, cognitive mapping, associative
learning, social learning and problem solving.
Learning = behavior modification resulting from specific experience; allows animals to change behavior in
response to changes in environments
 Habituation – loss of response after repeated exposure (learn not to respond) Hydra – touch &
scarecrow – crows
 Imprinting – irreversible, obtained during time window (sensitive period) strong bonds btw
parent & offspring
 Spatial Learning – requires landmarks
 Associative Learning – stimulus/response is associated (linked) to reward or punishment;
repeat: + behavior; avoid – behavior; Trial & Error first  learned response
 Social Learning – learning by observing the behavior others (predators learning how to hunt
from mom)
 Problem Solving – requires complex cognitive abilities (cognition = ability of an animals nervous
system to perceive, store, process, and use info gathered by sensory receptors) to apply past
experience to novel situations
5. In order for spatial learning to occur, what is needed? Landmarks What is the difference between a
kinesis and a taxis? Give an animal example for each.
kinesis = random movement in response to stimuli ex: pill bug
taxis = automatic movement to or away from stimulus ex: trout
6. What is a cognitive map? Give examples of animals who use this process and describe how they put it
to use. cognitive map = internal code of outside environment ex bird food storage, migratory patterns
of birds and whales
7. What two processes are involved in social learning? Describe this process with 2 animal examples.
Observation and imitation
Lions hunting & Vervet monkey calls
8. Distinguish between generalists and specialists with regards to foraging for food.
Generalists – eat anything available
Specialists – eat one or only a few things
9. The essential ingredient to all social behaviors like courtship, aggression and copperation is?
communication
10. What is territorial behavior used for? Give some animal examples of this behavior.
Parcel space and resources (feeding, mating, rearing young)
Ex. Song birds defend w/singing, squirrel chatting = defense, scent markers for boundaries
11. Describe examples of agonistic behavior and what are the outcomes?
Agonistic behavior = struggle; Outcomes = dominance hierarchies (mating, food, space)
Threats, combats, test of strength, exaggerated posture (making look bigger)
Don’t fight to death – settle disputes
12. Describe what types of communication signals would be given by diurnal, nocturnal and aquatic
animals.
 Diurnal (day)  visual & auditory
 Nocturnal (night)  odor & auditory
 Aquatic  electric signals, sound, chemicals
13. What is the definition of altruism? Give an animal example of this behavior.
Behavior to decrease fitness of individual while increasing fitness of others in population
Ex. Belding squirrel’s high pitch alarm puts himself in danger but increases safety of colony
14. What is inclusive fitness, kin selection and reciprocal altruism
 Inclusive fitness – behavior to perpetuate own genes and those of close relatives (similar related
genes; like nepotism)
 Kin selection – part of inclusive fitness, used to explain altruism among relatives
 Reciprocal Altruism – altruism btw non relatives; return favor same day; “you scratch my back – I’ll
scratch yours”
Chapter 36: Population Dynamics
1. Define a population and population density.
Population – all members of same species in a given area
Pop density - # of individuals in unit area or volume
2. Describe and draw (on a set of axes) the exponential growth model. What is the formula?
Exponential
Logistic
G = rN (r = per capita growth rate; N = population size)
3. What are factors which limit growth on a population?
Hunting, food, space, disease, competition
4. Describe and draw on a set of axes the logistic growth curve.
SEE # 2
G = rN (K-N/K) K= carrying capacity
5. What is the carrying capacity (“K”) showing you on a logistic growth curve?
Max # of individuals that ecosystem can hold
6. Define and give an example of “boom and bust” life cycles. Why does this happen?
Lots of growth followed by huge decline in growth
Population overcomes carrying capacity
7. Describe the differences between r-selection and k-selection. Give examples of each.
R: max reproductive success in uncrowded, unpredictable environment
Maximize the “r” (intrinsic rate of increase)
Early maturation, make many offspring (insects and weeds)
K: common in populations at or near carrying capacity (K)
Later maturation and mating
Few offspring but well cared for
Large land verts (polar bears)
8. Where does the US fall in the Human Ecological Footprint graph? What does it tell us?
US is already above “K” – we are using 4X our share of resources
Human Ecological Footprint = estimation of amt of land needed to support a given populations demands on
Earth’s resources
9. Under what 2 conditions may a country experience Zero Population Growth?
When birth rates = death rates:
High birth rates – high death rates
Low birth rates – low death rates
10. Describe the birth rate in China between 1950 and 2004. Why did this happen?
Birth rate decreased from 5.9 children/woman (1950) to only 1.7 children/woman (2004) because govt
imposed limit on children
11. Where does 80% of the global population live?
In developing countries – almost all global growth is occurring there
Chapter 37: Communities and Ecosystems
1. Define “community” and the four properties of communities.
Community: all organisms living in an area & their interactions
 Species diversity
 Dominant species
 Response to disturbances
 Trophic structure
2. What are the four species interactions which determine a community structure? What are all 4
influenced by?
All influenced by natural selection and evolution
Competition; predation; herbivory; symbiosis
3. Describe competition and why it takes place. Describe the paramecium example of the competitive
exclusion principle.
Must happen to gain hold of limited resources
One species uses resources more efficiently  reproduce more and wipe out other species
4. What is a niche? If 2 species occupy the same niche, what 2 things may happen?
Niche: species role in its community (sum total of its use of biotic/abiotic resources)
Death – less competitive species driven out
Change in habits – one species may evolve and adapt to use diff set of resources
5. What are some adaptations for predators and prey?
PRED: good senses, claws, camouflage, mimicry
PREY: quills, chemicals, mimicry, senses, camouflage
6. Distinguish batesian mimicry from mullerian mimicry and give animal examples for each.
B: one species mimics appearance of a harmful one ex/moth larvae looks and behaves like snakehead
M: 2 harmful and similar species gain wider range of protection by looking similar. Predators learn to avoid any
prey looking like this Ex/cukoo bee & yellow jacket wasp
7. Define a keystone species, give 2 animal examples and how their behavior gives them this title.
A species with a stong control over community structure because of its niche. Reduces the density of strongest
competitors Ex/starfish: if removed, increases mussel pop and decreases other populations
Ex/ sea otters in N pacific keep sea urchin population in check (if sea urchin pop increases, kelp population
decreases)
8. What are some adaptations which herbivores have? What are some of the plant defenses?
Herbivores: sensors to locate food, specialized parts to eat/digest plant material
Plant def: toxins (strychnine, morphine, nicotine), spines/thorns
9. Define symbiosis and give examples of the 3 types of symbiotic relationships.
Symbiosis – two living things in close contact/association
 Parasitism: +/- (pathogens)
 Mutualism: +/+ (ants & acacia trees)
 Commensalism +/0 (skin bacteria)
10. What is ecological succession?
Re-establishing life in an area after major disturbance
11. Distinguish primary succession from secondary succession and give examples of each.
Primary: begins in virtually lifeless area w/ no soil (new volcanic islands or rubble left by retreating glacier) Ex/
autotrophic bacteria  lichens & moss  soil made  grasses, shrubs  plants & trees (100-1000 yrs)
Secondary: after fire or flood of previously established area **soil remains
12. In primary succession, what life forms typically are on the scene first and who follows?
autotrophic bacteria  lichens & moss  soil made  grasses, shrubs  plants & trees
13. What is a trophic structure? Food chain? What is the sequence of a food chain?
Trophic structure = feeding pattern; food chain = sequence of food transfer up trophic levels
Producer  primary consumer (herbivore  secondary (carniviore)tertiary  quaternary
14. What is a detritivore and who are we talking about?
Feeds on dead/decaying material – scavengers (bacteria & fungi –also play roles as decomposers)
15. The actions of what 2 organisms are vital to recycling nutrients at all levels?
Bacteria & fungi
16. What is a food web?
Interconnected food chains. What you eat determines your level
17. Energy flow through an ecosystem is described as _one way___. Because of this, a constant input of
energy is needed from the __sun_?
18. Of all the visible light which reaches plants, only _1__% is converted to chemical energy thru
__photosynthesis________ reaction.
19. What is biomass defined as?
Mass of biotic factors in an ecosystem
20. What is the definition of primary production?
Amt of solar energy converted to chemical energy in a time period (170 bill tons of biomass/yr)
21. The pyramid of energy flow shows the loss of energy at each __trophic__ level. Describe the levels
and how much available energy is actually transferred from level to level.
Sun – 1%  plants – 10%  primary consumers – 10%  secondary –10%  tertiary
22. About 90% of energy at each level is either __used _ or _lost___ in the forms of ? heat, waste,
respiration
23. The energy available to top level consumers is very small. Why is this?
So much is lost in multiple trophic transfers
24. Why do top consumers (like a hawk) need a large area of territory to survive?
b/c it takes lots of vegetation to support trophic levels so far removed from photosynthesis
25. What is a biogeochemical cycle, list the 4 that exist in an ecosystem and briefly describe them.
Chemicals cycle between biotic/abiotic pools H20, C, N, P