Energy & Cycles
What is the role of a producer in an ecosystem?
Makes its own food and provides energy for consumers.
What are limiting factors in an ecosystem?
Factors that restrict population growth or size.
The process in which organisms with beneficial inherited traits survive and reproduce more successfully.
Natural Selection
What are homologous structures? Give an example.
Similar structures inherited from a common ancestor, such as a bird wing and horse leg.
The formation of a new species.
Speciation
Identify one process that removes carbon dioxide from the atmosphere.
Photosynthesis.
Give two examples of abiotic limiting factors.
Examples include water, sunlight, temperature, and space.
According to Darwin, which organisms are most likely to survive and reproduce?
Organisms with traits best suited to their environment.
How do fossils provide evidence for evolution?
Fossils show organisms that lived in the past and allow comparisons with organisms today.
This diagram shows evolutionary relationships among organisms based on shared characteristics.
cladogram
What role do decomposers play in nutrient cycling?
They break down dead organisms and return nutrients to the environment.
Explain the difference between density-dependent and density-independent limiting factors. Give one example of each.
Density-dependent factors are affected by population density, such as predation. Density-independent factors affect populations regardless of density, such as drought.
Explain how pesticide resistance develops in an insect population.
Resistant insects survive the pesticide and reproduce, passing resistance to their offspring.
Similarities in the embryos of different species are evidence of what?
Common ancestry
Two populations become separated for millions of years. Eventually, they can no longer reproduce and produce viable offspring together. What has occurred?
Speciation
Explain how energy flows through a food chain using the words producers and consumers.
Energy moves from the Sun to producers and then to consumers as organisms eat one another.
Describe the relationship between predator and prey populations using the words increase and decrease.
As prey increases, predators may increase; increased predators can then cause prey to decrease.
Explain how genetic variation contributes to evolution.
Variation creates differences among individuals that natural selection can act on.
A bird wing and a butterfly wing have the same function but different structures. What type of structures are these?
Analogous structures
This occurs when populations are physically separated and, over generations, accumulate differences that can eventually result in reproductive isolation.
geographic isolation
Producers contain 50,000 kcal of energy. How much energy is available to quarternary consumers?
5 kcal.
How could increased rainfall affect plant and herbivore populations?
More rainfall can increase plant growth, which provides more food and can increase herbivore populations.
Explain how natural selection can cause a population to change over time.
Organisms with beneficial traits reproduce more, making those traits more common over generations.
Scientists compare the DNA of two species and find that 98% of their DNA is similar. What does this suggest about the two species?
They are closely related.
On a cladogram, what do scientists compare to determine how organisms are related?
Shared traits