Passage I

SLEEPLESS is a fruit fly gene involved in sleep regulation. The normal form of this gene (S+) produces sleep factor protein; a mutant form (S-) does not produce the protein.

Researchers studied the sleep patterns and survival of flies of the same age that had the genotype S+S+, S+S- or S-S- . Figure 1 shows the amount of sleep, and the number of sleep events, per day per fly for each genotype. Figure 2 shows the amount of recovery sleep (additional sleep needed following 6 hr of sleep deprivation) per day per fly for each genotype. Figure 3 shows how percent survival varied with age for each genotype.

Figures adapted from Kyunghee Koh et al., "Identification of SLEEPLESS, a Sleep-Promoting Factor." ©2008 by the American Association for the Advancement of Science.

1. According to Figures 2 and 3, the flies with the genotype associated with the least amount of recovery sleep per day had a maximum life span of:

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

It can be seen from figure 2 that the genotype SS- has the least amount of recovery sleep per day;

It can be seen from figure 3 that all the genotypes have died since 60 days, so Life span is 60