Cyanobacteria pumped this into the atmosphere, creating an ozone layer.

Nitrogen

Oxygen

Methane

Ammonia

Why salt hurts wounds?

Explain show the equations used to calculate 24um2

What is the example of sexual reproduction a budding the cloning see conjugation and the binary fission

Type I alveolar cells: a. secrete surfactant. b. are squamous epithelial cells. c. are macrophages. d. function mainly in the diffusion of gases. e. Both B and D.

The correct order of hierarchy of structures in the body is

She is the northern hemisphere tilted toward the sun?

Describe how the ocean plays a role in stabilizing Earth's weather conditions

Q: A: Which numbered organelle produces ATP during cell respiration

From earliest to most recent, what is the correct order in which organisms appear in the fossil record? a. dinosaurs, invertebrates, reptiles, mammals b. invertebrates, amphibians, dinosaurs, mammals c.

Is it possible for technological advancements to have both positive and negative effects on the world