Ava was studying the history of Earth. She learned that radioactive decay helps scientists to determine rock ages. Explain how radioactive dating allows scientists to calculate the ages of rocks.

Out of the seven main animal groups (fish, mammals, birds, insects, reptiles, amphibians, and arachnids), how many contain members with internal backbones? a. 5 b. 3 c. 7 d. 1

Theories basic to all of the life sciences include the germ theory of disease. theory of evolution by natural selection. o two of these answers are correct none of these answers are correct o cell theory.

Recent research by marine biologists suggests that bottlenose dolphins have names for themselves. scientists played sounds they had identified as the names of particular dolphins, putting them through a synthesizer so that they did not sound like the voices of particular dolphins. the researchers found that dolphins would respond to the names of other dolphins that they were related to or associated with, but they ignored the names of strangers. this discovery suggests a much greater degree of self-awareness in aquatic mammals than was previously suspected. if this research holds up, what does it suggest about dolphins?