Scientists estimate that there are 8.7 billion animal species on the planet. There are about 400,000 plant species. New plants and animals are being discovered every day. Scientists who study these species have lots of choices to make and lots to learn. Now the choice is yours. Would you rather be covered in feathers or scales? Would you want to be an oak tree or a giant water lily? Would you choose to talk to animals or understand plants? It's your turn to pick this or that! Part of the This or That?: Science Edition series.