| Questions | 5 |
| Topics | Capillaries, Core, Force, Prefixes, Secondary Consumers |
Capillaries are small thin-walled vessels that permit the exchange of oxygen, carbon dioxide, nutrients, and waste between blood and the body's cells. This process of exchange is called diffusion.
The Earth's core is divided into the liquid outer core (1,430 miles or 2,300 km radius) and the solid inner core (745 miles or 1,200 km radius).
Force is applied to change an object's speed or direction of motion.
A prefix is added to the base units of the metric system to indicate variations in size. Each prefix specifies a value relative to the base unit in a multiple of 10. Common prefixes are:
| Prefix | Symbol | Relative Value | Example |
|---|---|---|---|
| mega | M | 106 (1,000,000) | Mm |
| kilo | k | 103 (1,000) | km |
| base unit | N/A | 1 | m |
| centi | c | 10-2 (1/100) | cm |
| milli | m | 10-3 (1/1,000) | mm |
Secondary consumers (carnivores) subsist mainly on primary consumers. Omnivores are secondary consumers that also eat producers. Examples are rats, fish, and chickens.