Community ecology (1) Flashcards
What are the different types of interspecific competitions?
-In mutualism, both populations benefit.
-In predation, one species (the predator) kills and eats another (the prey).
-In herbivory, an animal consumes plant parts or algae.
-In parasitism, the host plants or animals are victimized by parasites or pathogens
___________ occurs when populations of two different species compete for the same limited resource.
Interspecific competition occurs when populations of two different species compete for the same limited resource.
Define ecological niche.
An ecological niche is the sum of an organism’s use of the biotic and abiotic resources in its environment.
Give an example of mutualism. Explain their relationship.
Reef-building corals and photosynthetic dinoflagellates
-Photosynthetic dinoflagellates gain a secure shelter that provides access to light
-Produce sugars by photosynthesis that provide at least half of the energy used by the corals, and
-use the coral’s waste products, including carbon dioxide (CO2) and ammonia (NH3), a valuable source of nitrogen for making proteins.
What are the adaptations preys developed to predation?
Numerous adaptations for predator avoidance have evolved in prey populations through natural selection, including
-camouflage,
-mechanical defenses
-chemical defenses.
A plant whose body parts have been eaten by an animal must expend energy to replace the loss. True or false.
True. A plant whose body parts have been eaten by an animal must expend energy to replace the loss.
What are the defenses plants evolved against herbivores?
Plant defenses against herbivores include
-spines and thorns and
-chemical toxins, often the substances that we use medicinally or for other purposes
Define coevolution.
Herbivore-plant interactions illustrate coevolution, a series of reciprocal evolutionary adaptations in two species.
Give examples of external and internal parasites.
Internal parasites include nematodes and tapeworms.
External parasites include mosquitoes, ticks, and aphids.
Define trophic structure.
The trophic structure is a pattern of feeding relationships consisting of several different levels.
Define the Food chain.
The sequence of food transfer up the trophic levels is known as a food chain.
This transfer of food moves chemical nutrients and energy from producers up through the trophic levels in a community.
What are producers?
Producers are autotrophs that support all other trophic levels.
What are the different types of consumers?
-Herbivores are primary consumers.
-Secondary consumers typically eat herbivores.
-Tertiary consumers typically eat secondary consumers.
-Quaternary consumers typically eat tertiary consumers.
What are detritivores?
Detritivores derive their energy from detritus, the dead material produced at all the trophic levels
What are decomposers?
Decomposers
-are mainly prokaryotes and fungi
-secrete enzymes that digest molecules in organic materials and convert them into inorganic forms in the process called decomposition.
What are the two components species diversity is based on?
Species diversity is defined by two components:
-species richness, the number of different species in a community
-relative abundance, the proportional representation of a species in a community.
(if a community is species rich and has an even relative abudance , we say it is more diverse.)
What are keystone species?
Keystone species are one whose impact on its community is larger than its biomass or abundance indicates and that occupies a niche that holds the rest of its community in place.
Keystone species has low biomass or relative abundance, its removal from a community results in lower species diversity. True or false?
True.
What are disturbances?
Disturbances are events such as storms, fires, floods, droughts, or human activities that change biological communities by removing organisms from it or altering the availability of resources
What do disturbances cause?
-Ecological succession is a transition in the species composition of a community.
-Primary succession is the gradual colonization of barren rocks.
-Secondary succession occurs after a disturbance has destroyed a community but left the soil intact.
