Vocab
Pioneer species
first species that colonize newly exposed land
Natural selection occurs because:
Individuals with helpful traits are more likely to survive and reproduce
An organism’s niche includes:
Its habitat, resource use, and role in the community
According to the first law of thermodynamics, energy:
Cannot be created or destroyed, only transformed
What is ecological succession?
The gradual change and replacement of species in a community
Succession
changes that an ecosystem experiences over time
Which statement best describes genetic drift?
A change in a population’s gene pool due to chance events
Which term describes competition among members of the same species?
Intraspecific competition
Which process allows certain deep-ocean bacteria to produce sugars without sunlight
Chemosynthesis
Which situation is an example of primary succession?
A. Forest regrowth after a wildfire
B. Abandoned farmland returning to grassland
C. Plant growth on bare rock after a volcanic eruption
D. Replanting trees after logging
Plant growth on bare rock after a volcanic eruption
Biomass
total amount of living tissue an organism contains
Which mechanism of biological evolution involves changes in DNA that create genetic variation?
Mutation
When two species divide a shared resource by specializing in different ways, this process is called:
Resource partitioning
A wolf that eats a deer is classified as a:
Secondary consumer
Secondary succession differs from primary succession because it:
Happens where soil and some organisms still remain
Trophic level
level in a food pyramid (producer, consumer)
When individuals move into or out of a population and change its gene pool, this process is called
Gene flow
Which interaction is correctly matched with its description?
A. Mutualism — one benefits, the other is harmed
B. Commensalism — both species benefit
C. Parasitism — predator kills and consumes prey
D. Herbivory — an animal feeds on a plant
D. Herbivory — an animal feeds on a plant
Why are there usually only 3–4 trophic levels in a community?
Only about 10% of energy transfers to the next trophic level
Which organisms are most likely to be pioneer species?
Lichens and small plants
Detritivore
Consumes dead animals
The disappearance of a species from Earth is known as:
Extinction
Coevolution is best described as:
Two species evolving in response to changes in each other
What best describes a keystone species?
A species that has a disproportionately large impact on its community
A community in equilibrium is best described as:
Stable and balanced, with populations near carrying capacity