ESTUDYR
PCB 3044 EXAM 3 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
The Hudson’s Bay Company fur-trade records are useful in ecology because they:
A. Describe predator diets directly
B. Provide genetic samples of hares
C. C. Allow tracking of long-term population cycles of snowshoe hares ✔
Rationale: Fur returns recorded harvests over decades, revealing cyclical hare abundance.
What commonly causes population cycles in hare–lynx systems?
A. Climate only
B. Disease only
C. C. Limitation of food at high hare density and predation (lynx and others) reducing survival
✔
Rationale: Resource limitation and predator-driven mortality together drive cycles.
“Predation” is best defined as:
A. Mutualism between species
B. Herbivory only
C. C. A trophic interaction where one species (predator) benefits by consuming another (prey)
✔
Rationale: Predation involves direct consumption with fitness benefits for the predator.
“Parasitoids” are:
A. Microbes that help insect hosts
B. A type of herbivore only
C. C. Insects that lay eggs in a host; larvae develop inside and eventually kill the host ✔
Rationale: Parasitoids combine parasitism and lethal outcome for the host.
Predators typically focus foraging effort in areas that:
A. Are predator-free
B. Have fewer prey to reduce competition
C. C. Yield abundant prey (high prey density or profitability) ✔
Rationale: Optimal foraging theory predicts predators go where prey yield is high.
A “generalist predator” is one that:
A. Eats only one prey species
B. Never switches prey
,ESTUDYR
C. C. Consumes a wide variety of prey items based on availability ✔
Rationale: Generalists have broad diets and flexible foraging.
A “specialist predator” is characterized by:
A. Random prey choice only
B. Eating only plants
C. C. Preferring specific prey species regardless of alternate abundance ✔
Rationale: Specialists focus on certain prey due to adaptations or learned preferences.
“Search image” describes:
A. Predator camouflage pattern
B. A mapped territory for prey
C. C. A predator’s improved ability, via experience, to detect a particular prey type ✔
Rationale: Learning enhances detection, leading to focused predation on that prey.
Herbivores are often:
A. Broad diet generalists by default
B. Never specialized on plant parts
C. C. Specialists that consume specific plants or plant parts (leaves common) ✔
Rationale: Many herbivores target particular host species or tissues.
Which list orders nitrogen content from highest to lowest?
A. Seeds > animals > angiosperm leaves...
B. Xylem sap > phloem sap > animals...
C. C. Animals > seeds > angiosperm leaves > gymnosperm leaves > phloem sap > xylem sap ✔
Rationale: Animal tissue is nitrogen-rich; sap and woody leaves have less.
Herbivory typically reduces plant:
A. Flower color only
B. Geographic range only
C. C. Growth, survival, and reproduction (e.g., seed loss limits reproduction) ✔
Rationale: Tissue removal reduces plant fitness metrics.
Many herbivores feed on a narrow range of plants because:
A. All plants are equally nutritious
B. Predators force specialization only
C. C. Plant chemistry, morphology, and digestion constraints favor specialization ✔
Rationale: Adaptations and detoxification limits constrain diet breadth.
, ESTUDYR
Predators search for food by either:
A. Photosynthesizing
B. Only using social hunting
C. C. Actively searching (e.g., wolves) or sit-and-wait ambush strategies (e.g., some spiders)
✔
Rationale: Foraging modes vary between active hunters and ambushers.
For every prey defense there is usually:
A. No evolutionary response in predators
B. A permanent end to predation
C. C. A predator counter-adaptation or offense ✔
Rationale: Coevolutionary arms races produce matched defenses and offenses.
Predators commonly possess physical adaptations such as:
A. Rigid skulls only
B. Herbivorous dentition exclusively
C. C. Specialized jaws, teeth, or flexible skull bones enabling prey capture and consumption ✔
Rationale: Morphology evolves to improve prey capture and handling.
Poison and mimicry in predators are used to:
A. Help prey reproduce
B. Limit predator energy intake only
C. C. Subdue prey (venom) or blend into environment (mimicry/camouflage) ✔
Rationale: Chemical and visual strategies aid predation success.
Some predators tolerate prey toxins by:
A. Avoiding those prey entirely
B. Only eating during the day
C. C. Evolving resistance/detoxification mechanisms (e.g., garter snakes vs toxic newts) ✔
Rationale: Physiological adaptations allow consumption of toxic prey with costs.
Typical prey defenses include:
A. Only vocal warnings
B. Increased susceptibility to predators
C. C. Large size, rapid movement, body armor, crypsis, aposematism, mimicry ✔
Rationale: Morphological and behavioral traits reduce predation risk.
“Aposematic coloration” functions by:
A. Camouflaging prey from predators
PCB 3044 EXAM 3 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
The Hudson’s Bay Company fur-trade records are useful in ecology because they:
A. Describe predator diets directly
B. Provide genetic samples of hares
C. C. Allow tracking of long-term population cycles of snowshoe hares ✔
Rationale: Fur returns recorded harvests over decades, revealing cyclical hare abundance.
What commonly causes population cycles in hare–lynx systems?
A. Climate only
B. Disease only
C. C. Limitation of food at high hare density and predation (lynx and others) reducing survival
✔
Rationale: Resource limitation and predator-driven mortality together drive cycles.
“Predation” is best defined as:
A. Mutualism between species
B. Herbivory only
C. C. A trophic interaction where one species (predator) benefits by consuming another (prey)
✔
Rationale: Predation involves direct consumption with fitness benefits for the predator.
“Parasitoids” are:
A. Microbes that help insect hosts
B. A type of herbivore only
C. C. Insects that lay eggs in a host; larvae develop inside and eventually kill the host ✔
Rationale: Parasitoids combine parasitism and lethal outcome for the host.
Predators typically focus foraging effort in areas that:
A. Are predator-free
B. Have fewer prey to reduce competition
C. C. Yield abundant prey (high prey density or profitability) ✔
Rationale: Optimal foraging theory predicts predators go where prey yield is high.
A “generalist predator” is one that:
A. Eats only one prey species
B. Never switches prey
,ESTUDYR
C. C. Consumes a wide variety of prey items based on availability ✔
Rationale: Generalists have broad diets and flexible foraging.
A “specialist predator” is characterized by:
A. Random prey choice only
B. Eating only plants
C. C. Preferring specific prey species regardless of alternate abundance ✔
Rationale: Specialists focus on certain prey due to adaptations or learned preferences.
“Search image” describes:
A. Predator camouflage pattern
B. A mapped territory for prey
C. C. A predator’s improved ability, via experience, to detect a particular prey type ✔
Rationale: Learning enhances detection, leading to focused predation on that prey.
Herbivores are often:
A. Broad diet generalists by default
B. Never specialized on plant parts
C. C. Specialists that consume specific plants or plant parts (leaves common) ✔
Rationale: Many herbivores target particular host species or tissues.
Which list orders nitrogen content from highest to lowest?
A. Seeds > animals > angiosperm leaves...
B. Xylem sap > phloem sap > animals...
C. C. Animals > seeds > angiosperm leaves > gymnosperm leaves > phloem sap > xylem sap ✔
Rationale: Animal tissue is nitrogen-rich; sap and woody leaves have less.
Herbivory typically reduces plant:
A. Flower color only
B. Geographic range only
C. C. Growth, survival, and reproduction (e.g., seed loss limits reproduction) ✔
Rationale: Tissue removal reduces plant fitness metrics.
Many herbivores feed on a narrow range of plants because:
A. All plants are equally nutritious
B. Predators force specialization only
C. C. Plant chemistry, morphology, and digestion constraints favor specialization ✔
Rationale: Adaptations and detoxification limits constrain diet breadth.
, ESTUDYR
Predators search for food by either:
A. Photosynthesizing
B. Only using social hunting
C. C. Actively searching (e.g., wolves) or sit-and-wait ambush strategies (e.g., some spiders)
✔
Rationale: Foraging modes vary between active hunters and ambushers.
For every prey defense there is usually:
A. No evolutionary response in predators
B. A permanent end to predation
C. C. A predator counter-adaptation or offense ✔
Rationale: Coevolutionary arms races produce matched defenses and offenses.
Predators commonly possess physical adaptations such as:
A. Rigid skulls only
B. Herbivorous dentition exclusively
C. C. Specialized jaws, teeth, or flexible skull bones enabling prey capture and consumption ✔
Rationale: Morphology evolves to improve prey capture and handling.
Poison and mimicry in predators are used to:
A. Help prey reproduce
B. Limit predator energy intake only
C. C. Subdue prey (venom) or blend into environment (mimicry/camouflage) ✔
Rationale: Chemical and visual strategies aid predation success.
Some predators tolerate prey toxins by:
A. Avoiding those prey entirely
B. Only eating during the day
C. C. Evolving resistance/detoxification mechanisms (e.g., garter snakes vs toxic newts) ✔
Rationale: Physiological adaptations allow consumption of toxic prey with costs.
Typical prey defenses include:
A. Only vocal warnings
B. Increased susceptibility to predators
C. C. Large size, rapid movement, body armor, crypsis, aposematism, mimicry ✔
Rationale: Morphological and behavioral traits reduce predation risk.
“Aposematic coloration” functions by:
A. Camouflaging prey from predators
