How do scientists know that the first organisms were simple, unicellular organisms

High speed, high altitude wind that move air masses. What is that called?

Raj made the timeline below to show the progression of thinkers who developed theories about the earth's place in the universe.

Excessive loss of bone volume and mineral content associated with aging is

Lung cancer occurs slightly more frequently in the right lung than in the left lung (about 53% versus 47% of the time). the most logical explanation for this is that

What are the consequences of increased nitrogen and phosphorus into water systems?

Aristotle was a true scientist

What are the four major ocean basins? Are these basins connected?

Why is cellular respiration considered an efficient process

A student prepared a slide of pollen grains from a flower. First the pollen was viewed through the low-power objective lens and then, without moving the slide, viewed through the highpower objective lens of a compound light microscope.

If the number of phytoplankton decreases, what happens to the amount of carbon dioxide in the atmosphere?