Which rock layer (A, B, or C) should have fossils with the most carbon-14?

All reptiles are carnivores.

The structure numbered 4 (also numbered 11) is what?

Which basic nutrient contains nitrogen?

Investigators often look for anatomical features to determine the evolutionary relationship of two organisms

Which organ in the digestive system produces lots of enzymes and excretes them into the duodenal loop?

Some fish will take their fry into their mouths, then spit them back out when danger has passed.

African clawed frogs can carry a fungus that can kill several other species of native frogs.

Animals on a high protein diet should have their water intake restricted or they may overhydrate.

Viruses that infect bacteria are called ________________________.