PCB 3044
PCB 3044 - Ecology Exam 3 Questions
and Answers 2026 Update
What causes population cycles in hare and lynx?
- Limited food supply (if population density is high)
- Predation
When do hare reproductive rates reach their highest levels?
~ 5 years before hare density peaks
When do hare reproductive rates reach their lowest levels?
2-3 years after hare density peaks
Predator/prey relationships drive ________________ cycles and shift entire
__________________ communities
population; ecological
What is predation?
Trophic interaction where one species (predator) benefits by consuming
individuals of another species (prey)
Describe a carnivore, herbivore, omnivore, and parasite
- Carnivore: Eats animals
- Herbivore: Eats plants
- Omnivore: Eats plants and animals
- Parasite: Feeds off of the host it resides in
Do parasites kill their hosts?
Rarely
What are parasitoids?
Insects that lay eggs in another insect host. After the eggs hatch, the larvae
remain in the host and eat it
Why are parasitoids unusual predators?
Only have 1 prey over life
PCB 3044
,PCB 3044
Why are parasitoids unusual parasites
They kill the host
Predators tend to concentrate effort in areas that yield _______________ prey
abundant
What are generalist predators?
Predators that eat a broad range of prey, depending on availability
What are specialist predators?
Predators that show a preference for a certain species regardless of its
availability
Are most predators generalists or specialists?
Generalists
What is a search image?
Heightened ability of a predator to detect a target
What influences a search image of a predator?
- Experience of capturing and handling a specific type of prey several times
- The predator will start to focus its attention on prey that fit the search image
its familiar with
Describe the herbivore diet for most herbivores
- Narrow diet
- Specialize on particular plant parts (e.g., leaves, stems, roots, seeds)
- Specialize on particular plant species
Large herbivores tend to eat all _____________________ parts
aboveground
What part of plants is most commonly eaten? Why?
- Leaves
- They're abundant and often the most nutritious (except for seeds)
Give examples of herbivores that feed on a broad range of plant species
(generalists)
PCB 3044
, PCB 3044
Grasshoppers and golden apple snails
Seed eaters negatively impact a plants ___________________ success
reproductive
What are two types of foraging strategies used by predators?
- Actively search for food (e.g. wolves)
- Sit-and-wait until prey is in striking distance (e.g., sessile/immobile animals)
For any prey defense mechanism, there is usually a predator with a
______________________ offense
countervailing
Venomous spiders and snake subdue prey with ____________
poison
What is mimicry?
- A species can pretend to look like another species
- Predators can blend into the environment and catch prey off-guard
- Prey can pretend to look like a more harmful animal to scare off predators
What is aposematic coloration?
Brightly colored animals warn away predators because they may have toxins
What is crypsis?
Form of mimicry where prey camouflages to resemble its background
What is false advertising mimicry?
Shape or coloration of an non-toxic organism resembles another toxic organism
What is batesian mimicry?
A harmless species mimics a harmful one
What is mullerian mimicry?
Two or more harmful species mimic each other
Not foraging in open areas, keeping lookouts, and defensive circles are all
adaptations to ___________________
PCB 3044
PCB 3044 - Ecology Exam 3 Questions
and Answers 2026 Update
What causes population cycles in hare and lynx?
- Limited food supply (if population density is high)
- Predation
When do hare reproductive rates reach their highest levels?
~ 5 years before hare density peaks
When do hare reproductive rates reach their lowest levels?
2-3 years after hare density peaks
Predator/prey relationships drive ________________ cycles and shift entire
__________________ communities
population; ecological
What is predation?
Trophic interaction where one species (predator) benefits by consuming
individuals of another species (prey)
Describe a carnivore, herbivore, omnivore, and parasite
- Carnivore: Eats animals
- Herbivore: Eats plants
- Omnivore: Eats plants and animals
- Parasite: Feeds off of the host it resides in
Do parasites kill their hosts?
Rarely
What are parasitoids?
Insects that lay eggs in another insect host. After the eggs hatch, the larvae
remain in the host and eat it
Why are parasitoids unusual predators?
Only have 1 prey over life
PCB 3044
,PCB 3044
Why are parasitoids unusual parasites
They kill the host
Predators tend to concentrate effort in areas that yield _______________ prey
abundant
What are generalist predators?
Predators that eat a broad range of prey, depending on availability
What are specialist predators?
Predators that show a preference for a certain species regardless of its
availability
Are most predators generalists or specialists?
Generalists
What is a search image?
Heightened ability of a predator to detect a target
What influences a search image of a predator?
- Experience of capturing and handling a specific type of prey several times
- The predator will start to focus its attention on prey that fit the search image
its familiar with
Describe the herbivore diet for most herbivores
- Narrow diet
- Specialize on particular plant parts (e.g., leaves, stems, roots, seeds)
- Specialize on particular plant species
Large herbivores tend to eat all _____________________ parts
aboveground
What part of plants is most commonly eaten? Why?
- Leaves
- They're abundant and often the most nutritious (except for seeds)
Give examples of herbivores that feed on a broad range of plant species
(generalists)
PCB 3044
, PCB 3044
Grasshoppers and golden apple snails
Seed eaters negatively impact a plants ___________________ success
reproductive
What are two types of foraging strategies used by predators?
- Actively search for food (e.g. wolves)
- Sit-and-wait until prey is in striking distance (e.g., sessile/immobile animals)
For any prey defense mechanism, there is usually a predator with a
______________________ offense
countervailing
Venomous spiders and snake subdue prey with ____________
poison
What is mimicry?
- A species can pretend to look like another species
- Predators can blend into the environment and catch prey off-guard
- Prey can pretend to look like a more harmful animal to scare off predators
What is aposematic coloration?
Brightly colored animals warn away predators because they may have toxins
What is crypsis?
Form of mimicry where prey camouflages to resemble its background
What is false advertising mimicry?
Shape or coloration of an non-toxic organism resembles another toxic organism
What is batesian mimicry?
A harmless species mimics a harmful one
What is mullerian mimicry?
Two or more harmful species mimic each other
Not foraging in open areas, keeping lookouts, and defensive circles are all
adaptations to ___________________
PCB 3044
