Why are invasive species potentially dangerous? They can introduce foreign diseases and parasites
They decrease the number of predators in a food chain
They decrease competition for resources.
They increase the biodiversity in a population

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Drag each tile to the correct box. arrange the phases of mitosis in the correct order. 1 (condensation of chromosomes) 2 (separation of chromosomes) 3 (formation of spindle fibers) 4 (alignment of chromosomes in the center of the cell) 5 (pinching of the cell membrane)

Up until 1938, paleontologists accepted the idea that coelacanths (an ancient fish) went extinct at the time that they last appear in the fossil record, about 80 million years ago. but in 1938, a live coelacanth was discovered off the coast of south africa that was compared to the fossil record and found to be the same species what goal of science does this discovery represent