Which of the following human activities would affect the natural cycles on earth? a. burning fossil fuels c. factories giving off pollutants via smokestacks b. growth of agriculture d. all of the above

Aflame cell is at the end of each tubule of the nephridium malpighian tubules kidneys none of the above

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

African penguins, which inhabit the coasts of southern africa, were classified as an endangered species in 2010. two significant threats to their survival are ecosystem damage from oil spills and overfishing by humans. overfishing depletes the food supply of african penguins. the best method to reduce the threat of overfishing would be to . the risk of oil spills could be reduced by increasing the use of , which should oil consumption. if an oil spill does occur, could be used to remove the oil so the ecosystem may more quickly recover.