Section: Reading

81)

1. A division of the bryophytes, liverworts are relatively small plants which
2. have adapted to different habitats. Two species of liverworts, Riella and
3. Ricciocarpus, thrive in aquatic habitats. Some are found in the company of
4. other vegetation such as mosses, lichens, and sedges in the tundra in
5. Antarctica, while most others prefer moist, shady floors and tree trunks of
6. tropical forests. Leafy liverworts, with two or three rows of lobe-shaped
7. leaves which overlap incompletely, are discovered plentifully in the
8. tropical forests. These plants develop water storage pockets which become
9. home to a host of very small animals. They have a prostrate growth, and
10. single-cell rhizoids -- hairlike projections -- anchor the plant but are
11. incapable of transporting nutrients to the plant. The absence of a midrib is
12. quite common in bryophytes. Sphaerocarpo, a Thallus liverwort,
13. sometimes produces round rosettes or extended, flattened lobes.
14. The bryophytes not only aid soil formation on rocky and unproductive land
15. but balance the moisture content of the soil. Their epidermal cells -- outer
16. cells of the plant -- fused with significant air pores enclose the
17. photosynthetic cells. These pores play a major role in the photosynthetic
18. process in which carbon dioxide is taken in and oxygen is given off.
Why are the air pores important?

1. They restrain the flow of the gases.
2. They maximize the moisture loss.
3. They facilitate the photosynthetic action.
4. They absorb the soil's nutrients.

You must understand the relationship between ideas to answer this question correctly. This information can be inferred from the second paragraph (lines 16-18). Choices (A), (B), and (D) are not true.