| Questions | 5 |
| Topics | Blood Cells, Ecosystem, Minerals, Prefixes, Pulmonary Artery & Vein |
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.
An ecosystem is a biological community of interacting organisms and their physical environment. This includes both the biotic (living) and abiotic (non-living).
Small quantities of certain minerals like iron, calcium, magnesium, and salt are important for nutrition and health.
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 |
The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.