Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems? Energy transfer between trophic levels is usually less than 20 percent efficient. Nutrient cycling rates tend to be limited by decomposition. Many primary and higher-order consumers are opportunistic feeders. Decomposers compete with higher-order consumers for nutrients and energy.

Recent research by marine biologists suggests that bottlenose dolphins have names for themselves. scientists played sounds they had identified as the names of particular dolphins, putting them through a synthesizer so that they did not sound like the voices of particular dolphins. the researchers found that dolphins would respond to the names of other dolphins that they were related to or associated with, but they ignored the names of strangers. this discovery suggests a much greater degree of self-awareness in aquatic mammals than was previously suspected. if this research holds up, what does it suggest about dolphins?

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4

Brian made this table to organize his notes on changes of state change of state energy change melting gain freezing lose deposition gain condensation lose