1: Plants/Animals Inhabited First

Correct Responses

• PLANTS with an explanation based plants being able to make their own food (photosynthesis).
  • Examples:
    • Plants can photosynthesize.
• PLANTS with an explanation based only on survival OR mode of transportation of plants/animals. [Photosynthesis or making food not explicitly mentioned.]
  • Examples:
    • They could survive there first because plants only need water and air.
    • Without plants there would not be animals.
    • First the plants arrived. Then the animals can come and survive by eating the plants.
    • Seeds could just be carried by the wind. Animals would have to swim a long distance.
    • Seeds from South America blew to the islands.
• ANIMALS with a reasonable explanation based on transportation AND availability of alternative food sources (may be implicit based on the specific type of animal named).
  • Examples:
    • Birds could fly over to the island to nest and survive by eating fish from the sea.
    • Seals can swim there and live on the rocky shore. [Assumes seals eat fish.]

Incorrect Responses

• PLANTS with no explanation or an incorrect explanation. [May include a correct statement that does not apply to the situation.]
  • Examples:
    • They just grew from the ground.
    • Because plants grow faster and live longer.
    • They are living organisms.
    • Plants were on Earth before animals.
• ANIMALS with no explanation or an incorrect explanation.
  • Examples:
    • Birds could just eat the seeds in the ground.
    • They are everywhere.
    • There will be a surplus of food.
    • Animals can move but plants cannot.
    • Animals migrate.
• Other incorrect

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2A: Effect of Cats

Correct Response

• Refers to cats preying upon other organisms, or similar (resulting in a reduction in population).
  • Examples:
    • They might pass on diseases to other animals.
    • The cats help them by eating the rats and mice.
    • Their prey could become extinct.

Incorrect Responses

• Refers only to an effect on the cat with no explicit effect on other organisms.
  • Examples:
    • They cannot survive on the island.
    • Cats might reproduce and get out of control.
• Other incorrect

2B: Effect of Goats

Correct Responses

• Refers only to the goats eating plants (resulting in a reduction of the amount of plant life on the island).
  • Examples:
    • Large pieces of grass will disappear as the goats eat it.
    • It could lead to erosion if the goats clear the land by eating all the plants.
• Refers to an effect of the goat on other animals (e.g., competition for food/habitat, as a food source for predators, etc.). [Note: may also refer to the goats eating plants.]
  • Examples:
    • The animals that eat goats would have more food.
    • They might become a source of food.
    • The goats will eat up the plants and the populations that depend on plants will decrease.

Incorrect Responses

• Refers only to an effect on the goat with no explicit effect on other organisms.
  • Examples:
    • Goats would have more babies.
    • They would die because they don’t have any food.
• Other incorrect

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3A: Description of Beak Sizes

Correct Responses

• Gives a description based on similarities that is supported with information in the graphs.
  • Examples:
    • Both are similar in average beak size.
• Gives description based on differences that is supported with information in the graphs.
  • Examples:
    • Species 1 is a little bit shorter than Species 2.
    • Species 2 has more that are big.
    • Species 2 has a wider range of depth than of Species 1.
• Give a description that includes both similarities and differences.
  • Examples:
    • Both species have the greatest amount of birds with 11mm beak depths, but Species 1 does not have birds with beak depths bigger than 13mm.

Incorrect Responses

• States only that the two species are the ‘same’ or ‘similar’ without supporting information from the graphs.
  • Examples:
    • They are nearly the same.
• States that one species is larger or smaller than the other, but does not identify which.
  • Examples:
    • One of them is a bit different on beak depth.
• Other incorrect

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3B: Types of Seeds Eaten

Correct Responses

• States that the two species eat the same (similar) types of seeds. [Response to A indicates that the two species have the same or similar size beaks.]
• States that Species 2 eats larger seeds than Species 1. [Response to A indicates that Species 2 is larger.]
• States only that birds (finches) with larger beaks eat larger seeds (or similar). [No explicit comparison of the two species.]

Incorrect Responses

• States that the two species eat the same (similar) types of seeds, but this conclusion is inconsistent with the response given in Part A.
• States that one species eats larger seeds than the other, but this conclusion is inconsistent with the response given in Part A.
• Other incorrect

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4: Graphs of Beak Depths for Species 3 and 4

Correct Response

• A with an explanation that relates the difference in beak size to reduced competition (or similar).
  • Examples:
    • With the different sized beaks they would not have to share food.
    • One species will eat the small seeds and one will eat the large seeds.
    • They each have their own food source.

Partial Response

• A with a minimal explanation that refers only to the difference in beak size. [Does not explicitly mention competition for seeds or similar.]
  • Examples:
    • Because they are different sizes.
    • Because Species 3 has a smaller beak size.

Incorrect Responses

• A with no explanation or an incorrect explanation.
  • Examples:
    • Because their beaks look sharper.
    • Because both species have a large beak to the percentage of population.
    • It’s like the other graphs.
• B with no explanation or an incorrect explanation.
  • Examples:
    • Bigger beak depths so they could eat more seeds.
    • Both are nearly equal and are a more normal size.
    • It ’s better if they are the same size because they eat the same seeds.
• Other incorrect

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