ecologist are concerned about the accumulation of harmful chemicals are positions on predators such as the Barn Owl. DDT, PCBs, organophosphate pesticides, and heavy metals such as mercury are some of these chemicals. Why do you think predatory animals like owls are often threatened in habitats that have been exposed to these chemicals?

Joe is breeding cockroaches in his dorm room. he finds that the average wing length in his population of cockroaches is 4 cm. he chooses the six cockroaches that have the largest wings; the average wing length among these selected cockroaches is 10 cm. joe interbreeds these selected cockroaches. from earlier studies, he knows that the narrow-sense heritability for wing length in his population of cockroaches is 0.6. a. calculate the selection differential and expected response to selection for wing length in these cockroaches. b. what should be the average wing length of the progeny of the selected cockroaches?

This group of organisms perform the process of ammonifcation. a. herbivores b. decomposers c. carnivores c. plants

Why does bubbling occur when vinegar mixed with baking soda