69. The main DISADVANTAGE of excessive gluconeogenesis during prolonged postabsorptive periods is that (A) continued protein breakdown can impair enzymatic activity and plasma membrane functions. (B) carbohydrate buildup in the liver impairs its function. (C) the brain is exposed to levels of glucose that are too high. (D) tissues other than the brain increase glucose utilization.

76. Most bird species that form flocks show a negative relationship between flock size and individual vigilance (i.e., the larger the flock, the less often an individual lifts its head to scan the surrounding environment). However, some bird species have shown a positive relationship between flock size and individual vigilance. The positive relationship is particularly strong when flocks are space-constrained, such as in small ponds or fields. What is the most likely explanation for this? (A) As flock size increases, the number of "cheaters" increases, so individuals must spend more time scanning for predators. (B) As flock size increases, the risk for interference and aggression between members increases, so individuals must scan for both conspecifics and predators. (C) As flock size increases, the risk of predation for any given member increases, so individuals must spend more time scanning for predators. (D) As flock size increases, mating opportunities decrease, so individuals must spend more time scanning for potential mates.

相關試題

相關試卷