The habitats of terrestrial animals, which provide food, shelter, and places to bear and raise offspring, have been changing at an unnatural pace in recent centuries. The restriction of a once large, continuous habitat into smaller, segmented pieces is called habitat fragmentation. This process occurs over all types of habitats and is widely recognized as one of the major barriers to effective conservation efforts.
Habitat fragmentation occurs when the landscape is changed so that plants and animals no longer have access to all of the same areas they once did. In some cases, this process can occur because part of the habitat has been destroyed, leaving animals with less roaming space than they previously had. In other cases, the habitat still exists, but a barrier emerges that prevents animals from reaching all areas of their former habitat. Regardless of how it occurs, habitat fragmentation can be dangerous to both plants and animals. Plants are unable to respond quickly to change, so if they rely on an aspect of their habitat that no longer exists, there is often not enough time to adapt, and the plant will die off. Animals are more commonly able to move into the smaller habitat areas, but they suffer nonetheless. They may be cut off from food or shelter. Often, the resources remaining can support only a smaller population, leaving the animals vulnerable to disease.
While habitat fragmentation can be devastating to populations, it naturally occurs over time. Mountains will rise, volcanoes will erupt, and rivers will change course. Any of these changes and countless other natural progressions will segment large areas into smaller ones. It is widely accepted, however, that the primary source of habitat fragmentation in the modern world is human activity. As humans expand into new areas, they change the environment to suit their needs. Habitats are destroyed to make way for man-made buildings and are divided to connect those buildings. Plants and animals that encroach into areas where humans live are repelled or killed. Edge species, which live on the borders of habitats, expand as more borders are created and will compete with species that cannot live on edges. The increased competition in a decreased space endangers many species.
Four specific activities or structures are known as the most common causes of man-made habitat fragmentation: roads, housing developments, agriculture, and logging. Roads require an extensive expanse of land to be cleared, including the area surrounding the road. A single road will split a large habitat into two smaller ones and increase the edge area. Animals that attempt to traverse the road to reach land that may be essential for their survival are in additional danger from fast-moving cars.
Housing developments are necessary, as the population of humans continues to grow. Such development not only forces land to be cleared, but also creates competition between humans and edge species. Animal and pest control keep many native species from coming into housing developments. Non-native species, particularly plants, are regularly introduced into housing developments for the benefit of the occupants. Population growth also leads to the need for more agriculture. Consequently, large tracts of land are bulldozed and the natural plants destroyed to make way for crops. The cleared land has lost all its utility to the plants and animals that once called that area home. Finally, logging, whether for industrial uses or for firewood, destroys large trees that may be necessary for species’ survival. Removing trees shrinks the habitat and could eliminate both food and shelter. At the same time, the presence of humans, their equipment, and the roads they need can imperil plants and animals in the area.
For a thriving and robust species, ample area, reasonable competition, and access to essentials are all necessary. If habitat fragmentation continues at the current pace, species will be restricted to areas in which only small populations can survive or will lose the ability to survive entirely. Conserving large tracts of land in a variety of areas is already underway and may help to slow this process.
Now answer the questions.
| P1 | Paragraph 1 |
| S1 | The habitats of terrestrial animals, which provide food, shelter, and places to bear and raise offspring, have been changing at an unnatural pace in recent centuries. |
| 2 | The restriction of a once large, continuous habitat into smaller, segmented pieces is called habitat fragmentation. |
| 3 | This process occurs over all types of habitats and is widely recognized as one of the major barriers to effective conservation efforts. |
According to paragraph 1, what is true of habitat fragmentation?
| P2 | Paragraph 2 |
| S1 | Habitat fragmentation occurs when the landscape is changed so that plants and animals no longer have access to all of the same areas they once did. |
| 2 | In some cases, this process can occur because part of the habitat has been destroyed, leaving animals with less roaming space than they previously had. |
| 3 | In other cases, the habitat still exists, but a barrier emerges that prevents animals from reaching all areas of their former habitat. |
| 4 | Regardless of how it occurs, habitat fragmentation can be dangerous to both plants and animals. |
| 5 | Plants are unable to respond quickly to change, so if they rely on an aspect of their habitat that no longer exists, there is often not enough time to adapt, and the plant will die off. |
| 6 | Animals are more commonly able to move into the smaller habitat areas, but they suffer nonetheless. |
| 7 | They may be cut off from food or shelter. |
| 8 | Often, the resources remaining can support only a smaller population, leaving the animals vulnerable to disease. |
The words “an aspect” in the passage are closest in meaning to
According to paragraph 2, which of the following occurs more with plants that suffer habitat fragmentation than with animals that suffer habitat fragmentation?
According to paragraph 2, a cause of habitat fragmentation is
| P3 | Paragraph 3 |
| S1 | While habitat fragmentation can be devastating to populations, it naturally occurs over time. |
| 2 | Mountains will rise, volcanoes will erupt, and rivers will change course. |
| 3 | Any of these changes and countless other natural progressions will segment large areas into smaller ones. |
| 4 | It is widely accepted, however, that the primary source of habitat fragmentation in the modern world is human activity. |
| 5 | As humans expand into new areas, they change the environment to suit their needs. |
| 6 | Habitats are destroyed to make way for man-made buildings and are divided to connect those buildings. |
| 7 | Plants and animals that encroach into areas where humans live are repelled or killed. |
| 8 | Edge species, which live on the borders of habitats, expand as more borders are created and will compete with species that cannot live on edges. |
| 9 | The increased competition in a decreased space endangers many species. |
The word “source” in the passage is closest in meaning to
According to paragraph 3, what currently has the greatest influence on habitat fragmentation?
The word “endangers” in the passage is closest in meaning to
| P4 | Paragraph 4 |
| S1 | Four specific activities or structures are known as the most common causes of man-made habitat fragmentation: roads, housing developments, agriculture, and logging. |
| 2 | Roads require an extensive expanse of land to be cleared, including the area surrounding the road. |
| 3 | A single road will split a large habitat into two smaller ones and increase the edge area. |
| 4 | Animals that attempt to traverse the road to reach land that may be essential for their survival are in additional danger from fast-moving cars. |
Why does the author mention “roads,” “housing developments,” “agriculture,” and “logging”?
| P5 | Paragraph 5 |
| S1 | Housing developments are necessary, as the population of humans continues to grow. |
| 2 | Such development not only forces land to be cleared, but also creates competition between humans and edge species. |
| 3 | Animal and pest control keep many native species from coming into housing developments. |
| 4 | Non-native species, particularly plants, are regularly introduced into housing developments for the benefit of the occupants. |
| 5 | Population growth also leads to the need for more agriculture. |
| 6 | Consequently, large tracts of land are bulldozed and the natural plants destroyed to make way for crops. |
| 7 | The cleared land has lost all its utility to the plants and animals that once called that area home. |
| 8 | Finally, logging, whether for industrial uses or for firewood, destroys large trees that may be necessary for species’ survival. |
| 9 | Removing trees shrinks the habitat and could eliminate both food and shelter. |
| 10 | At the same time, the presence of humans, their equipment, and the roads they need can imperil plants and animals in the area. |
The word “utility” in the passage is closest in meaning to
Why does the author mention “firewood”?
| P6 | Paragraph 6 |
| S1 | For a thriving and robust species, ample area, reasonable competition, and access to essentials are all necessary. |
| 2 | If habitat fragmentation continues at the current pace, species will be restricted to areas in which only small populations can survive or will lose the ability to survive entirely. |
| 3 | Conserving large tracts of land in a variety of areas is already underway and may help to slow this process. |
Which of the sentences below best expresses the essential information in the highlighted sentence in paragraph 6? Incorrect choices change the meaning in important ways or leave out essential information.
It can be inferred from paragraph 6 that compared with fragmented habitats, habitats that have not been fragmented
| P5 | Paragraph 5 |
| S1–2 | Housing developments are necessary, as the population of humans continues to grow. Such development not only forces land to be cleared, but also creates competition between humans and edge species. |
| 3–4 | A Animal and pest control keep many native species from coming into housing developments. Non-native species, particularly plants, are regularly introduced into housing developments for the benefit of the occupants. |
| 5–6 | B Population growth also leads to the need for more agriculture. Consequently, large tracts of land are bulldozed and the natural plants destroyed to make way for crops. |
| 7–8 | C The cleared land has lost all its utility to the plants and animals that once called that area home. Finally, logging, whether for industrial uses or firewood, destroys large trees that may be necessary for species’ survival. |
| 9–10 | D Removing trees shrinks the habitat and could eliminate both food and shelter. At the same time, the presence of humans, their equipment, and the roads they need can imperil plants and animals in the area. |
Look at the part of the passage that is displayed above. The letters [A], [B], [C], and [D] indicate where the following sentence could be added.
These species compete with native plants and often exacerbate habitat fragmentation.
Where would the sentence best fit?
An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
Habitat fragmentation is a process that poses a threat to the survival of some plant and animal species.