Questions 31-40
Complete the notes below.
Write ONE WORD ONLY for each answer.
With wolves returning, things started to change.
This caused those areas to regenerate.
The answer is creatures. The phrase in the note states: "Trophic cascade: An ecological phenomenon occurs when an animal at the top of the food chain affects ______ at the bottom." From the listening script, it says: "A trophic cascade is an ecological process that starts with an animal at the top of the food chain and makes an impact on creatures at the bottom of the chain." The sentence directly refers to 'creatures' at the bottom, making this the most precise one-word answer.
Associated Text:
A trophic cascade is an ecological process that starts with an animal at the top of the food chain and makes an impact on creatures at the bottom of the chain.
The answer is absent. The note asks for the status of wolves before their reintroduction: "wolves in Yellowstone Park had been ______ for 7 decades." According to the script, the lecturer says, "Before the wolves were reintroduced – they'd been absent for 70 years..." This makes 'absent' the correct word to complete the sentence.
Associated Text:
Before the wolves were reintroduced – they'd been absent for 70 years
The answer is vegetation. The question asks what was reduced in the park due to increased deer numbers. The script states, "Those deer had reduced the vegetation there to almost nothing. They had just grazed it away – eaten it." This directly points to 'vegetation' as the one-word answer.
Associated Text:
Those deer had reduced the vegetation there to almost nothing. They had just grazed it away – eaten it.
The answer is behavior. The question focuses on what the deer changed to avoid wolves. The relevant line in the script is, "they changed the behavior of the deer. The deer started avoiding certain parts of the park – the places where they could be trapped most easily by the wolves..." Clearly, 'behavior' is the word needed.
Associated Text:
they changed the behavior of the deer. The deer started avoiding certain parts of the park – the places where they could be trapped most easily by the wolves
The answer is height. The sentence in the note is "some trees growing five times in ______ in just six years." The script says, "the height of the trees increased by five times in just six years." Thus, 'height' is correct as it fits the blank precisely.
Associated Text:
the height of the trees increased by five times in just six years
The answer is beavers. The question asks which other animals increased in number besides birds. The lecture says, "The number of songbirds started to increase greatly. The number of beavers also started to increase because beavers like to eat the trees." Therefore, 'beavers' is the word to enter.
Associated Text:
The number of songbirds started to increase greatly. The number of beavers also started to increase because beavers like to eat the trees.
The answer is habitats. The note is about what beaver dams provided for other animals. The lecture: "the beavers built dams in the rivers that provided habitats for ducks, fish and reptiles." So, 'habitats' directly answers the question.
Associated Text:
the beavers built dams in the rivers that provided habitats for ducks, fish and reptiles.
The answer is roots. The question asks what part of regenerating trees and plants prevented soil erosion. This is answered in the script: "there were now trees and plants with strong roots holding the soil together, that prevented soil erosion." Hence, 'roots' is the correct choice.
Associated Text:
there were now trees and plants with strong roots holding the soil together, that prevented soil erosion.
The answer is pools. The question focuses on what increased and was important for wildlife habitats. The script says, "The river narrowed. More pools formed. This was important for wildlife habitats." The word 'pools' is the correct answer.
Associated Text:
The river narrowed. More pools formed. This was important for wildlife habitats.
The answer is ecosystem. The note asks, besides the physical geography, what else was changed by the wolves. As per the script: "the wolves, small in number, transformed not just the ecosystem of the Yellowstone National Park but also its physical geography." This shows 'ecosystem' is the required answer.
Associated Text:
the wolves, small in number, transformed not just the ecosystem of the Yellowstone National Park but also its physical geography.
