1. In evolutionary biology, what is the best definition of an "adaptive trade-off"?
- A. A process where an entire species loses a trait over many generations because it is no longer needed.
- B. A relationship where two different species help each other survive in the same environment.
- C. When a trait has both benefits and costs for an organism's survival and reproduction.
- D. A beneficial mutation that appears suddenly within a population due to environmental stress.
2. In a lake where dragonfly larvae are the main predators, why is having low armor considered an adaptive trait for stickleback fish?
- A. It requires less calcium, which is a rare nutrient in the lake's ecosystem.
- B. It allows for greater speed to escape the slow-grabbing predators.
- C. It makes the fish appear smaller and less appealing as a meal to the larvae.
- D. It is a dominant gene that always expresses itself over the gene for heavy armor.
3. Which statement accurately describes the specific trade-off for a stickleback fish having heavy armor?
- A. It offers better protection from predators but makes the fish heavier and slower.
- B. It allows the fish to eat tougher food but requires more energy to grow.
- C. It makes the fish more attractive to mates but also more visible to predators.
- D. It provides more protection but reduces the fish's ability to live in warmer water.
4. The stickleback population in the lake has more low-armor individuals over time primarily because:
- A. slower, armored fish get eaten more often.
- B. the lake's water chemistry dissolves heavy armor plates.
- C. individual fish can choose to shed their armor to become faster.
- D. the dragonfly larvae find heavily armored fish to be less nutritious.
5. Imagine a new predator is introduced to the lake: a bird that swoops down and tries to pierce the fish with its sharp beak. How would this change the adaptive value of armor?
- A. Low armor would still be better because speed is always key.
- B. The fish would need to develop camouflage instead of relying on armor.
- C. Heavy armor would likely become more adaptive, as it could potentially deflect the bird's piercing beak, making survival more likely.
- D. Neither trait would be adaptive, and the fish would quickly go extinct.
6. What is the direct environmental pressure that caused the stickleback population to favor the Low Armor trait?
- A. Changes in water temperature.
- B. A decrease in available food.
- C. Predation by dragonflies.
- D. Competition with other fish species.
7. In the context of constructing a scientific argument, what is a 'claim'?
- A. The verifiable data and facts collected from an experiment.
- B. A concluding statement that answers the scientific question being investigated.
- C. The step-by-step procedure used to conduct the investigation.
- D. The logical justification that explains how the evidence supports the conclusion.
8. Which statement best summarizes the evolution of the stickleback population described?
- A. The sticklebacks decided to have less armor so they could swim faster.
- B. Dragonflies caused a genetic mutation for Low Armor to appear in the fish.
- C. An existing trait that improved survival against a predator became more common over generations.
- D. The stickleback population evolved simply because it needed to adapt to the presence of dragonflies.
9. In the scientific argument about stickleback evolution, which statement best represents the *reasoning* that connects the evidence to the claim?
- A. The stickleback population in the lake now has mostly Low Armor plating.
- B. Data shows that fish with Low Armor are captured less often by dragonflies.
- C. Sticklebacks with the genetic trait for Low Armor were more likely to survive, reproduce, and pass that trait to their offspring.
- D. Dragonfly predation is the main reason for the shift in the stickleback population.
10. How does the process of natural selection explain the increase in Low Armor sticklebacks over time?
- A. Individual fish changed their armor during their lifetime to become faster and then passed that change on.
- B. The Low Armor trait provided a survival advantage, leading to greater reproductive success for those fish.
- C. The dragonflies intentionally chose to eat only the fish with High Armor, leaving the others to survive.
- D. The gene for Low Armor spontaneously appeared in the entire population at once due to the predator.