Biological Evolution
What is the term for a change in gene frequencies within a population over time?
Evolution
What do we call organisms that produce their own organic food using sunlight or inorganic chemical energy?
Autotrophs/producers
What ecological interaction occurs when two organisms require the same limited resource?
Competition
What group of native Hawaiian birds evolved from a common ancestor into species with different beak shapes and diets?
Hawaiian honeycreepers
During photosynthesis, plants remove which greenhouse gas from the atmosphere?
Carbon dioxide
A hurricane randomly kills most individuals in a small beetle population. The survivors have very different gene frequencies. What evolutionary mechanism is this called?
Genetic drift
In the chain grass → grasshopper → frog → snake, what trophic level does the frog occupy?
Secondary consumer
A flea feeds on a dog's blood, benefiting while harming the deer. What interaction is this?
Parasitism
What introduced disease, transmitted by mosquitoes, has contributed to declines in Hawaiian forest birds?
Avian malaria
What is the name of the method used to estimate tree biomass from measurements such as trunk diameter without cutting down the tree?
Allometry
A male bird's bright feathers increase his chances of mating but also make him more visible to predators. What evolutionary process can favor this trait?
Sexual selection
A bear eats berries, insects, and fish. What kind of heterotroph is the bear, and which trophic level does it reside in?
Omnivore, multiple trophic levels
Two bird species live in the same forest but feed on insects at different heights in the trees. What ecological process reduces competition between them?
Competitive exclusion/resource partitioning
At Hakalau Forest, many bird populations improved following restoration, but the Hawaiian ‘ākepa showed little improvement. What important habitat requirement helps explain this?
The ‘ākepa requires nesting cavities in mature trees.
A tree contains 400 kg of dry biomass. If 45% of that biomass is carbon, how many kilograms of carbon does it store?
180 kg (400 * 0.45)
Two frog populations live in the same forest but breed during different seasons. What kind of reproductive isolation is this?
Temporal isolation
Producers store 50,000 units of chemical energy. Assuming 10% transfer efficiency at each level, how many units reach tertiary consumers?
5,000 units
Sea otters eat sea urchins, which eat kelp. Predict what happens to kelp forests if sea otters are removed and explain why.
Kelp forests will disappear because urchin populations will increase uncontrollably.
After the Mount St. Helens eruption, manually seeded plots initially developed more vegetation than unseeded plots. Why did researchers eventually find that the two types of plots became more similar?
Natural colonization and ecological succession gradually increased vegetation and species richness in unseeded plots.
A household reduces its annual CO₂ emissions from 50,000 pounds to 40,000 pounds. What percentage reduction has it achieved?
20% (50,000 - 40,000) / 50,000 X 100
Two isolated lizard populations diverge genetically for thousands of generations. When reunited, they can mate, but their hybrid offspring are sterile. Has speciation occurred under the biological species concept? Explain.
No. Speciation must result in viable, fertile offspring.
A student argues that a vulture is a decomposer because it eats dead things. Identify the flaw in this thinking.
A vulture is not a decomposer because it does not directly convert the dead organisms into nutrients. It converts them into waste, which is broken down into nutrients by decomposers (bacteria, fungi).
What kind of keystone predators are otters in our sea urchin/sea kelp example?
Type 2 (predators eat lower-level predators, allowing their prey to survive)
Silver carp invade a lake and both gizzard shad and bigmouth buffalo decline. Explain the likely mechanism, and identify the kind of experimental evidence that would help demonstrate causation.
Competition for limited plankton. Controlled experiments comparing native fish growth or survival with and without silver carp would help demonstrate causation.
Using the lab's estimate of 19,000 pounds of CO₂ removed per forest acre per year, how many acres would theoretically offset 95 million pounds of annual emissions?
5,000 acres