Question

from what are sky islands?
sky islands are isolated mountain ranges in southeastern arizona and northern mexico. some of the mountains rise more than 6,000 feet above the surrounding desert floor, making the lowlands and high peaks drastically different. plants and animals living in the mountains could never survive in the surrounding deserts. thus by analogy, the mountains are \islands\ surrounded by deserts that are \seas.\
(from \what are sky islands?\ by u.s. forest service, usda)
based on the information in this passage, how are sky islands and the islands in oceans alike?

1. both have high elevations.
2. both can be difficult to access.
3. both are isolated by geographical features.
4. both have threatened plant and animal populations.

Explanation:

• Option 1: Ocean islands don't necessarily have high elevations (e.g., low - lying coral islands), while sky islands' high elevation is due to mountains, so this is incorrect.
• Option 2: The passage doesn't mention the accessibility of either sky islands or ocean islands, so this is not supported.
• Option 3: Sky islands are isolated by deserts (geographical feature), and ocean islands are isolated by oceans (geographical feature). This matches the analogy in the passage where mountains are "islands" surrounded by desert "seas" and ocean islands are surrounded by ocean "seas".
• Option 4: The passage doesn't discuss threatened populations for either, so this is incorrect.

Answer:

1. Both are isolated by geographical features.