Also in 2025 Practice Test B English, question 33.
Passage Using Fire to Keep a Prairie Healthy
Using Fire to Keep a Prairie Healthy
Inside the 40,000-acre Joseph H. Williams Tallgrass Prairie Preserve in northern Oklahoma, herds of bison roam on the scenic land that is home to hundreds of different species of plants and animals. While one of the greatest threats to the prairie is wildfire, the use of controlled fires is actually an effective way to protect this idyllic landscape.
Fires that are started by lightning or other natural circumstances are inevitable, and the results can be disastrous. However, hundreds of years ago the American Indian people who inhabited the Great Plains area between Minnesota and Texas realized that these fires could also be helpful. The bison in the area seemed to prefer grazing on tender new grass on the recently burned land rather than on grass in the unburned areas. The American Indian people began to deliberately burn areas of land for bison to graze on, which enticed the herds away from the people’s crops.
Today conservationists at the Tallgrass Prairie Preserve and farmers in the Great Plains continue to use controlled burns for land management. Intentionally burning a portion of land can dramatically improve the quality of the vegetation that regrows there. The fires burn away weedy undergrowth and help limit the overcrowding of shrubs and trees in the burn area, creating less competition for water and nutrients. Additionally, the process of burning excess plant matter adds nitrogen, an essential element for plant growth, to the soil.
One common target of controlled burns at the preserve and the surrounding area is the invasive red cedar tree. A single red cedar tree can consume up to 40 gallons of water per day, taking this vital resource away from other plant life. These tall trees also cast shade that prevents sunlight from reaching the plants beneath them. The fast-growing red cedar trees tend to crowd out prairie grasses, the primary food source for wild and domestic animals that make the prairie their home. An imbalance in one component of the prairie’s ecosystem affects the entire web of life. Controlled burns help maintain this ecosystem’s delicate balance.
Of course, these controlled fires are intended to burn only a portion of an area. A total burn, which is a risk with an uncontrolled wildfire, would destroy all wildlife as well as the crops farmers plant for income. The key to using controlled fires is knowing which areas of land to burn and when. Conservation experts at the preserve employ the “patch-burn” approach, meaning they rotate which portion of land is burned each year. They study the land to find out which areas would most benefit from being burned, and then they arrange about a dozen burns over one-third of the land. This patch burning contains the fire within a specific area and allows animals in the burn area to safely relocate. The following year, conservationists will burn a different section of the preserve, while the land burned the previous year regrows healthier than before.
Researchers have tracked and studied the variety of plant species and animals that live on the preserve, and their studies show that the patch-burn approach has restored biodiversity to the area by promoting the growth of species that were at risk of being crowded out. The patch-burn system is so successful that the conservationists at the preserve provide training to prairie farmers about conducting controlled burns on their own land. Burning land to make it healthy may seem counterintuitive, but strategic controlled fires have helped the prairie sustain life for hundreds of years and, with careful management, will continue to do so.
Question
Targeting red cedar trees in controlled burns affects the animals that live on the prairie mostly by
- Aensuring that the animals’ main food source has the conditions needed for it to thrive.
- Bendangering the animals that live near the trees scheduled for removal.
- Cmaking sure that the water supply for the animals is sufficient.
- Dreducing the animals’ natural source of shade and protection from the elements.
Show the answer
Correct answer: A
The question asks how targeting red cedar trees in controlled burns affects the animals that live on the prairie.
A. CORRECT. According to information in paragraph 4, targeting invasive red cedar trees with controlled burns affects animals that live on the prairie by ensuring that these trees do not “crowd out prairie grasses, the primary food source for wild and domestic animals that make the prairie their home.” The paragraph also states that each red cedar tree consumes “up to 40 gallons of water per day, taking this vital resource away from other plant life.” Removing red cedars thus increases the amount of water available to the prairie grasses and helps maintain favorable conditions for the animals’ main source of food.
B. Incorrect. Although the author mentions the potential danger to wildlife from an uncontrolled burn in paragraph 5, the author emphasizes that patch burning “allows animals in the burn area to safely relocate.” Therefore, the animals that live near trees scheduled for removal are not endangered by the controlled burns.
C. Incorrect. In paragraph 4, the author states that “a single red cedar tree can consume up to 40 gallons of water per day, taking this vital resource away from other plant life.” However, the author does not suggest that reducing the number of red cedar trees through controlled burns ensures a sufficient water supply for animals that live on the prairie.
D. Incorrect. In paragraph 4, the author states that “these tall trees also cast shade that prevents sunlight from reaching the plants beneath them.” However, the author does not suggest that using controlled burns to eliminate red cedar trees reduces a natural source of shade for prairie animals. The red cedar trees are invasive; therefore, the author does not consider them a “natural” part of the prairie ecosystem.
Question analysis
This question asks how burning invasive red cedar trees on purpose mostly affects the wild and domestic animals that live on the Oklahoma prairie. Students follow a chain of cause and effect through the paragraph on red cedars, which describes the trees' heavy water use, their shade and their spread, and must pick out the effect that matters most to the animals.
- Grade level
- Grade 7 reading and task
- Compared with grade 7
- At grade 7 Grade 7 readers routinely trace how one change leads to another in an informational text. This chain stays within one paragraph, but the paragraph names several things the cedars take from the prairie, and the stem's “mostly” asks for the main effect.
- Estimated difficulty
- Moderate: several steps, or a close reading with one strong distractor.
- Thinking it demands
- Depth of knowledge 2, skills and concepts · mainly analyze
- What makes it hard
- Reading between the lines moderate
- Much to keep track of minor
- The right answer is reworded minor
- Evidence
- Answered from one paragraph or stanza
- Reading level
- Passage: about grade 11, 598 words; question and choices: about grade 9, 66 words.
- Students, last 30 days
- Not enough answers yet to show (it takes 10).
Why it is hard, traps and wrong answers (shows the answer)
Why it is hard
Paragraph 4 lists three harms the red cedar does, drinking water, casting shade and crowding out grasses, and the wrong choices hand the water and the shade straight to the animals. In the text, all three harms fall on plants, and animals feel them only through the grasses they eat. Students who ask who suffers each harm see that protecting the food supply is the main effect the stem’s “mostly” asks for.
Reading between the lines moderate Working it out
Paragraph 4 never names an effect on animals; students must chain the cedars crowding out “prairie grasses,” the grasses being “the primary food source,” and the burns that remove the cedars. (Graesser, Singer & Trabasso, 1994; Kintsch, 1998)
Much to keep track of minor Working it out
The paragraph names three harms at once, 40 gallons of water a day, shade over the plants below and crowding, and students must track which living things each harm reaches. (Sweller, 1988; Carpenter, Just & Shell, 1990)
The right answer is reworded minor Choosing the answer
The right choice speaks of “conditions needed for it to thrive” without naming grass or cedars, while the wrong ones repeat the paragraph’s vivid details of water and shade. (Freedle & Kostin, 1993; Kirsch & Mosenthal, 1990)
Strategy: Reread the paragraph about red cedars and list each way the trees harm the prairie, then ask which of those harms reaches the animals and which would matter to them most.
Traps
- Twists what the text says: Uses the text's topic and ideas but changes what it says: who did it, how much, when, or why.
- Outside knowledge: A choice is plausible in the real world but not supported by this text.
The wrong answers, classified
B Outside knowledge (King et al., 2004; Recht & Leslie, 1988)
Assumes that fire near animals must endanger them, a common belief, though paragraph 5 says patch burning “allows animals in the burn area to safely relocate.”
C Twists what the text says (King et al., 2004)
Seizes on the 40 gallons a red cedar drinks each day, but the passage says that water is taken from “other plant life,” not from the animals’ supply.
D Twists what the text says (King et al., 2004)
Turns the cedars’ shade, which blocks sunlight from “the plants beneath them,” into shelter for animals, though the passage treats the invasive trees as a harm, never a natural refuge.
Working it out, step by step
Figure out what the question asks
This question asks about cause and effect. People burn red cedar trees on purpose. You need to find how that mostly helps the animals. The word “mostly” means you want the biggest effect, not just any effect.
Find what the red cedars do
Paragraph 4 is about red cedars. It names three harms. First, one tree can drink “up to 40 gallons of water per day, taking this vital resource away from other plant life.” Second, the trees “cast shade that prevents sunlight from reaching the plants beneath them.” Third, they “tend to crowd out prairie grasses, the primary food source for wild and domestic animals.”
Ask who each harm hurts
Look at who loses each time. The water is taken from “other plant life.” The shade blocks light from “the plants beneath them.” The crowding pushes out prairie grasses. So every harm falls on plants. The animals feel it through the grass, because grass is their main food. Primary means main. So burning the cedars mostly helps the animals by protecting their food.
Check each choice
- A is right. The animals’ main food source is prairie grass. With the cedars gone, the grass gets water, sunlight and room to grow.
- B is wrong. Paragraph 5 says patch burning “allows animals in the burn area to safely relocate.” Relocate means move somewhere else.
- C is wrong. The cedars take water from plants. The passage never says the animals run short of water.
- D is wrong. The shade blocks light from plants. The passage never calls it shelter for animals.
Watch out: The 40 gallons of water is a striking fact, so C is tempting. But that water is taken from “other plant life.”
Choose the answer
Burning the cedars keeps the grass healthy, and the grass feeds the animals. Thrive means grow well. So the answer is A: “ensuring that the animals’ main food source has the conditions needed for it to thrive.”
Why this answer and not the closest wrong one
C is the closest wrong answer, because paragraph 4 does talk about water. But it says the cedars take water from plants, not from animals. The grass, the animals’ main food, is what suffers from all three harms. So A fits better.
More questions like this
The original DOE question
The passage “Using Fire to Keep a Prairie Healthy” as printed (page 41)
