The plants in this image bloom in autumn. Which statement best describes why these plants bloom in autumn?
The nights are longer.
The nights are shorter.
The nights are colder.
The nights are warmer.

In which situations is the principle of cross-cutting relationship useful in determining relative age?

Select the correct answer from each drop-down menu the images show fossils of a modern bird and two extinct organisms (a tyrannosaurus rex and an archaeopteryx). based on the structure of the three organisms, it can be concluded that the archaeopteryx and bird have wings, while dinosaurs have limhe se it can be concluded that

Part a - which gene to compare? in this exercise, you will use the cytochrome c oxidase i (coi) gene to investigate relationships among salmon species. (this gene encodes a protein that functions in the mitochondrial electron transport chain.) you will compare the coi gene sequences from your salmon test samples to the standard sequences for each salmon species. in order for the coi gene to be useful for distinguishing among the different salmon species, which three statements must be true?