Vocabulary
A previously absent allele appears in a rabbit population following an accidental change in DNA, introducing variation without necessarily improving survival.
What is mutation?
Two wetland species rely on the same declining food supply, creating an interaction in which access to a limited resource affects both populations.
What is competition?
In a wetland food web, marsh grasses capture sunlight and store energy in sugars, making that energy available to organisms at higher trophic levels.
What are primary producers or autotrophs?
The maximum number of individuals of a species that an ecosystem can support over time with its available resources.
What is carrying capacity?
A nonnative species spreads rapidly after entering a new community. Identify one missing limiting factor that could help explain its growth
What is A predator, parasite, or competitor?
A population of fish develops a different distribution of inherited scale-color alleles over several generations, demonstrating this change in its gene pool.
What is biological evolution?
A bird builds its nest in a tree, gaining shelter while the tree experiences no measurable benefit or harm.
What is commensalism?
In the chain marsh grass → grasshopper → frog → snake, the frog occupies this trophic level because it obtains energy from a primary consumer.
What is the third trophic level?
In a wetland food web, the rabbit population decreases significantly. Hawks rely on both rabbits and snakes for food. This type of population change can affect organisms that are not directly connected to rabbits through feeding relationships.
What is an indirect effect?
An energy pyramid contains 50,000 kJ at the producer level. Calculate the approximate energy available to tertiary consumers.
50 kJ. 50,000 → 5,000 → 500 → 50 kJ.
A hurricane randomly eliminates most of a small island population. The surviving individuals have different allele frequencies, even though their traits did not influence survival.
What is genetic drift?
A harmless insect resembles a harmful species, causing predators that have learned to avoid the harmful species to avoid the harmless one as well.
What is mimicry?
Scientists use this representation rather than a single food chain to explain how declining insect populations could simultaneously affect frogs, fish, and birds through interconnected feeding relationships.
What is a food web?
Food, water, space, disease, and competition can restrict population growth when they become scarce or increasingly influential.
What are limiting factors?
After a wildfire, a forest retains its soil and some surviving seeds. Grasses establish first, followed by shrubs and young trees. This ecological process explains the community's recovery without requiring soil formation from bare rock.
What is secondary succession?
Rabbits from a neighboring habitat enter an isolated population and reproduce, introducing alleles that were previously absent from its gene pool.
What is gene flow?
A tick attaches to a marsh rabbit and obtains nourishment from its blood. The tick benefits while the rabbit loses resources and may experience reduced health, illustrating this type of species interaction.
What is parasitism?
A wetland's producers contain 36,000 kJ of available energy. Applying the approximate 10% transfer rule twice gives this amount of energy to secondary consumers.
What is 360 kJ?
Two populations occupy the same ecosystem and depend heavily on the same limited food source. As both populations increase, fewer resources are available per individual, reducing survival and reproduction. This density-dependent interaction can regulate both populations.
What is Competition?
A severe hurricane changes vegetation, reduces several animal populations, and disrupts feeding relationships in a previously balanced wetland. The community's shift away from its earlier stable condition is described by this ecological term.
What is disequilibrium?
Following a decline in their usual food source, rabbits with an inherited ability to digest an alternative plant produce more surviving offspring. Over several generations, the associated allele increases in frequency.
What is natural selection?
Over generations, a predator develops improved resistance to its prey's toxin while the prey develops a more potent toxin, illustrating reciprocal evolutionary changes between interacting species.
What is coevolution?
Removing a predator causes herbivores to increase, producers to decline, and other populations to change, demonstrating the disproportionately strong influence of this type of species on community structure.
What is a keystone species?
A population temporarily exceeds the number of organisms its ecosystem can sustainably support. Increased competition reduces available resources, mortality rises, and the population subsequently declines. This sequence demonstrates the relationship among limiting factors, population size, and this ecosystem property.
What is carrying capacity?
Excess nutrient runoff enters an established freshwater ecosystem, altering water conditions and the organisms living there. Because the aquatic community existed before the disturbance, its subsequent changes illustrate this type of succession.
what is water succession?