4/11 Predator-Prey Interactions and Mutualistic Interactions

Question 1

Biomass

Answer 1

the amount of material that is wrapped up in any one particular grouping

Question 2

Biomass between trophic levels

Answer 2

• biomass of plants is always greater than the biomass of herbivores
• the biomass of herbivores is always greater than the biomass of carnivores

this is because energy is lost as trophic level increases

Question 3

secondary metabolites

a form of chemical defense

Answer 3

• the chemical byproducts of a lot of different chemical reactions that the plants then have evolved to use as a way of decreasing predators
• often bitter tasting

Tannin is a secondary metabolite made by oak trees, it binds to proteins in the plant that makes the tannin undigestible

Question 4

Constitutive Defenses

Answer 4

a mechanical defense that is always turned on, such as an armadillo shell

Question 5

Inducible defenses

Answer 5

mechanical defenses that are turned on by noticement of a predator, example zebra running from a cheetah

Question 6

Crypsis

Answer 6

another word for camoflague

Question 7

Apopsematic coloring

Answer 7

bright or contrasting colors that draw attention to the organism often because they contain dangerous chemicals (conspicuous signaling unpatability)

ex. milkweed alkaloids and hydrogen cyanide in ladybugs

Question 8

Mullerian Mimicry

Answer 8

several species using the same coloring to signal unpatability to predators

ex. honeybee, wasp, and bumblebee

Question 9

Batesian Mimicry

Answer 9

harmless species mimick the appearance of harmful species

ex. mimic octopus, viceroy butterfly, hornet wasp/wasp beetles/hover fly

Question 10

How does adding in food change population size?

Answer 10

• Adding food to prey population will increase more than if you took away predators
• If you add food and decrease predators, the prey population will be the largest it can get

Question 11

Parasitism vs. Parasitoidism

Answer 11

• parasitism does not typically kill the host or intend to, parasitoidism does

Question 12

Ectoparasites vs. endoparasites

Answer 12

Ectoparasites live outside the body (pubic lice, and ticks), endoparasites live inside the body (hookworm/tapeworm)

Question 13

Commensalism

Answer 13

• (+/0) interaction
• Burdock example

Question 14

Amensalism

Answer 14

• (-/0) interaction
• Example: Deer steps on bug

Question 15

Symbiosis

Answer 15

two individuals living in constant contact

Question 16

Obligate Mutualism

Answer 16

• the relationship is required for the survival or reproduction of the individuals involved in the mutualism

Question 17

Facultative

Answer 17

the relationship is not a requirement for survival or reproduction of the individuals

Question 18

Explotative Interactions

Answer 18

• (+/-) interactions
• ex. predator/prey and parasite/host

Question 19

Why are there more explotative interactions than there are species?

Answer 19

Because all species are food for a number of other species and host to a variety of parasites and pathogens

Question 20

Which three explotative interactions are considered consumption?

Answer 20

• herbivory
• parasitism
• predation

Question 21

population inertia

Answer 21

the tendency for a population to move beyond some change and then take awhile to incorporate that change into their dynamic

Question 22

What are the least available food types?

Answer 22

• high energy plant foods like seeds, fruit, and flowers are the least available food types

Question 23

search image

Answer 23

a visual and chemical focus on the most abundant or rewarding prey type while ignoring nearby but otherwise good prey for at least as long as the focal prey is the most economical to pursue

Question 24

Mechanical defenses of plants

Answer 24

• tough epidermis on seed shells, and bark on branches
• entanglement devices thick waxy cuticle and plant hair on leaves and stems entangles and deters small herbivores
• piercing devices cutting edges in wetland species, spines and needles

also, polymers within tissues such as cellulose and lignin are indigestible by herbivores on their own