Which of the following describes how different species depend on one another in a natural environment?
a. non-native kudzu out-compete native plants in the eastern united states.
b. giant african snails imported as pets damage native plants and crops in hawaii.
c. grasslands in the california floristic province have been converted into housing projects, shopping centers, and roads.
d. acacia trees of central and south america provide shelter for stinging ants, while the stinging ants snip surrounding plants that grow too close.

Mr. j, age 42, is a construction worker in las vegas. he recently noticed that a mole on his face seemed to be getting larger and darker. at first he did not worry because he was in the sun a lot and assumed the change may have been caused by sunburn. after a month, not only was the mole larger and darker, but it appeared to be “bumpy.” his doctor diagnosed a malignant melanoma skin cancer following biopsy of the nevus. mr. j reports pain in his right shin that does not go away when he puts his feet up or sleeps. discussion questions 1. relate mr. j’s skin changes to the warning signs for malignant melanoma. (see malignant melanoma.) 2. discuss the normal progression of this malignancy. what is the significance of the bone pain that mr. j is experiencing? (see malignant melanoma.) 3. discuss the treatment available for this patient and the prognosis for recovery. (see malignant melanoma.)