Considering the graph of a line with a negative slope.

The different forms of a gene for a given trait are called .

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.

What are the three stages of volcanic activity? a. active, magma, lava c. extinct, eruption, explosive b. eruption, quiet, explosive d. active, dormant, extinct