| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.70 |
| Score | 0% | 74% |
In the metric system, what prefix represents 10-3?
mega |
|
kilo |
|
milli |
|
centi |
In the metric system, milli is the prefix for 10-3.
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
reflection |
|
Doppler effect |
|
refraction |
|
sound radiation |
The Doppler effect occurs when the source or listener (or both) of sound waves is moving. If they're moving closer together, the listener perceives the sound with a higher pitch and, when they're moving apart, the listener perceives the sound with a lower pitch.
Changes to an object's speed or direction of motion are caused by which of the following?
work |
|
power |
|
a force |
|
kinetic energy |
Force is applied to change an object's speed or direction of motion.
In the food chain, bacteria and fungi convert the organic matter in the dead bodies of plants and animals into simple nutrients. Bacteria and fungi are:
scavengers |
|
decomposers |
|
primary consumers |
|
producers |
Decomposers (saprotrophs) are organisms such as bacteria and fungi that break down the organic matter in the dead bodies of plants and animals into simple nutrients.
Which of these is not a component of blood?
red blood cells |
|
plasma |
|
white blood cells |
|
marrow |
Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.