One of the most peculiar living creatures known to biologists is the bdelloid rotifer. This microscopic creature has a host of properties, from the surprising to the truly bizarre. Bdelloid rotifers can live in any type of freshwater, from hot springs near the Dead Sea to partially frozen ponds on Antarctica. These creatures are surprisingly resilient; when their watery homes freeze up or dry out, the rotifers enter into a state of suspended animation. When in this state, rotifers can withstand temperatures as low as one degree above absolute zero, the temperature of the void of space, for over an hour. The suspended rotifers are picked up by wind currents and are blown about the globe. When they land in a suitable home, the rotifers re-animate and return to their primary business–eating bacteria and producing new rotifers. The rotifers reproduce so rapidly that a single organism could fill a medium-sized lake with its descendants in about two months.

Strangely, there are no male bdelloid rotifers. Or if there are, biologists have never discovered them. There are over five hundred species of bdelloid rotifers and not one of them has any male members. As may be expected, there is little variation in the rotifer genome. Biologists have found that certain genes may differ in individual rotifers by as much as 30 percent. From this variation and the known rate of mutation in the rotifer genome, biologists conclude that the rotifers gave up sex between 40 and 80 million years ago.

1. The passage implies which of the following about male rotifers?

A. There have never been male rotifers.
B. Male rotifers, if discovered, would have more variation in their genome than do females.
C. It is possible that male rotifers exist.
D. Male rotifers existed 40 million years ago.
E. Male rotifers have a higher rate of mutation than females do.



2. According to the passage, a rotifer might be found in all of the following locations EXCEPT

A. a thermal pool
B. outer space
C. the atmosphere
D. a dried up puddle
E. an iceberg



3. The passage implies which of the following about the state of suspended animation used by the rotifers?

A. Rotifers are oblivious to their outside surroundings when in the state of suspended animation.
B. A rotifer in a state of suspended animation can survive indefinitely.
C. Rotifers do not enter a state of suspended animation unless their homes freeze up or dry out.
D. Rotifers enter the state of suspended animation when they want to move to a more desirable habitat.
E. Rotifers in a state of suspended animation have some ability to sense the conditions of the environment around them.