Charles Darwin spent over 20 years developing his theory of natural selection.

What is in the stomach of a frog

What type of rock formed the first continent

The male cardinal is bright red. The female is a dull brown. Why are the two birds different colors?

Aerobic respiration, anaerobic glycolysis, and hydrolysis of phosphocreatine can all be used by vertebrate muscle cells to generate atp during active periods. in what order are these mechanisms employed?

In a paragraph, explain how the end of the California drought worsened the severity of the wildfires.

How are seeds different from spores? A. seeds have endosperm which provides nourishment for a new plant, but spores do not have any food supplies B. Spores involve egg and sperm cells, while seeds do not C.

What type of extreme weather does global warming cause?

Just as the body has different levels of organization, such as cells, tissues, organs, and organ systems, so does an ecosystem.

The electric signal for a contraction passes rapidly from one heart muscle cell to the next by way of

What is the BEST example of Newton's 1st law of motion? Group of answer choices A rocket will push off the ground with the same force as the ground pushes on the rocket.