Question

read the passage. there are several questions about this passage.
ten degrees of latitude boasts only thirty-five species of snakes. almost twice that number occur in la selvas five square miles, as if a house full of serpents were packed into a thimble, and there are nearly four hundred species of birds, more than half as many as in the continental united states. tropical faunas encompass more lifestyles too, thanks to rampant adaptive diversification; most temperate bats feed on insects, for example, whereas some of their hothouse relatives specialize on fruit, nectar, fish, frogs, or birds.

3
this dramatic global variation has long intrigued naturalists, and its causes are partly understood. rainforests usually occupy middle latitudes, so earth’s most biologically opulent regions are hot and wet. some of them have been that way for millions of years, during which rising seas and tectonic events fragmented landscapes, catalyzing the origin of new species. more land, more sun, and more rain, coupled with geographical isolation and geological time, have fostered plant evolution—and thereby more plant-eating insects, insect-eating frogs, frog-eating snakes, and birds and mammals that eat them all. at local scales earthquakes, volcanoes, and windstorms annihilate chunks of habitat, which are then colonized by species that live in the resulting light gaps. those sun-loving newcomers are eventually replaced by shade-tolerant species, so that natural disturbances further increase diversity by generating patchworks of succession in what at first glance appears to be unbroken forest.

4
tropical biotas are also among the most endangered anywhere, their most charismatic inhabitants often difficult to find. ecotourists adore emerald-and-red quetzals and iridescent blue morphos, and with coaching they might tolerate the jararaca pitvipers whose venom chemistry inspired a popular blood pressure drug. predators are usually tough to see, though. whereas in an hour a person might find dozens of snakes on a missouri hillside, i averaged one a day at la selva, and after twelve months of...

this question has two parts. answer part a, and then answer part b.

part a
what is the relationship between the structure of paragraph 3 and the structure of paragraph 4?

1. paragraph 3 tells what rainforests look like to visitors, and paragraph 4 compares visits to rainforests with visits to other wild places.
2. paragraph 3 gives examples of the effect of natural events on rainforests, and paragraph 4 gives examples of the effect of human interference.
3. paragraph 3 gives reasons that rainforests have large numbers of animal species, and paragraph 4 explains how visitors can appreciate those species.
4. paragraph 3 focuses on what happened to rainforests over long periods of geological time, and paragraph 4 focuses on what is happening in the present day.

part b
what is the irony suggested by the relationship in the correct answer from part a?

Explanation:

Part A

• Analyze Option 1: Paragraph 3 is about the causes of rainforest species diversity, not what rainforests look like to visitors. Paragraph 4 is about ecotourism and endangered biotas, not comparing rainforest visits to other wild places. Eliminate 1.
• Analyze Option 2: Paragraph 3 discusses natural events (rising seas, tectonic events, earthquakes, volcanoes, windstorms) and their effects on rainforest diversity. Paragraph 4 talks about human interference (ecotourism, endangerment) and gives examples of how humans interact with rainforest species. This matches.
• Analyze Option 3: Paragraph 3 gives reasons for species diversity, but Paragraph 4 is about the endangerment of tropical biotas and ecotourism, not how visitors appreciate species. Eliminate 3.
• Analyze Option 4: Paragraph 3 includes both long - term (millions of years) and local - scale (earthquakes, etc.) events, not just long - term geological time. Paragraph 4 is about the endangerment of biotas and ecotourism, not just present - day events. Eliminate 4.

From Part A, Paragraph 3 shows how natural processes (like geological events, natural disturbances) have led to rainforests having a large number of diverse species over time. Paragraph 4 shows that human interference (ecotourism is a form of human interaction, and the biotas are endangered due to human activities) is now threatening these same diverse and unique rainforest ecosystems that natural processes created. The irony is that the very natural processes that made rainforests rich in species are now being undermined by human actions, and the rainforests, which have such a rich biodiversity (partly due to natural events), are among the most endangered, and even the charismatic species that should be easy to find (because of the high diversity) are difficult to find due to human - caused endangerment. Also, the natural events that fostered diversity are now being countered by human interference, and the rainforests, which are a result of long - term natural processes, are being threatened in the present by human activities.

Answer:

1. Paragraph 3 gives examples of the effect of natural events on rainforests, and paragraph 4 gives examples of the effect of human interference.

Part B