How can you tell if something is living when you are looking at it through a microscope

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.