| Questions | 5 |
| Topics | Base Units, Cambrian Period, Central & Peripheral Nervous Systems, Cumulus Clouds, Proton |
| Measurement | Base Unit | Example |
|---|---|---|
| length / distance | meter (m) | km |
| mass | gram (g) | kg |
| volume | liter (L) | mL |
| volume (medical) | cubic centimeter (cc) | cc |
| time | second (s), minute (min), hour (h) | ms, min, h |
| temperature | centigrade (°C) | °C |
The Cambrian period is one of the most significant geological time periods. Lasting about 53 million years, it marked a dramatic burst of changes in life on Earth known as the Cambrian Explosion. It is from this period that the majority of the history of life on Earth, as documented by fossils, is found. Called the fossil record, the layering of these mineralized imprints of organisms preserved in sedementary rock have allowed geologists to build a historical record of plant and animal life on Earth.
The nervous system consists of the brain and spinal cord (central nervous system) and the peripheral nervous system which is the network of nerve cells (neurons) that collect and distribute signals from the central nervous system throughout the body.
Cumulus clouds are large, puffy, mid-altitude clouds with a flat base and a rounded top. These clouds grow upward and can develop into a cumulonimbus or thunderstorm cloud.
A proton is a subatomic particle found in the nucleus of an atom. It carries a positive electric charge.