The list below shows some events which took place at different periods in the geologic time scale.

1. fish with craniums appear 2. mammals appear 3. sharks appear

which of these best orders that events from the earliest to the most recent?

Which of the following is true of minerals? a / Grown by farmers when needed b / Cannot be used to generate electricity c / Used in industries to build products d / Always found in groups

Explain the importance of nutrients to an organism of your choice

What is precipitation cycle?

Hakeem is testing the effects of sunlight on samples of soil. Which of these actions would introduce confounding variables into Hakeem's experiment? He tests a theory that's already been established. He tests multiple hypotheses at a time.

A scientist studying a form of marine bacteria growing in culture dishes, observed a mold called Penicillium also growing in some of the dishes.

An element's atomic number is 49. How many electrons would an atom of this element have?

Which is the ability of a cell membrane to allow materials to pass through it called

The brain and spinal cord are formed from a. the notochord, which forms from endoderm b. the neural tube, which forms from mesoderm c. the neural tube, which forms from ectoderm d. the notochord, which forms from mesoderm

Missy spencer was given penicillin for tonsillitis. she developed a severe life-threatening allergic (hypersensitivity) reaction to the penicillin. her medical file records this reaction as a (n) :

What situation most likely explains the occasional high frequency of certain inherited disorders among human populations established by a small population?