| Questions | 5 |
| Topics | Acidity, Cell Division, Light Waves, Secondary Consumers, Vitamins |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
Cell division is the process by which cells replicate genetic material in the nucleus. Cell division consists of several phases:
| Phase | Major Process |
|---|---|
| interphase | chromosomes replicate into chromatids and the cell grows |
| prophase | chromatids pair up |
| metaphase | paired chromatids move to opposite sides of the cell |
| anaphase | cell elongates and nucleus begins to separate |
| telophase | separation of nucleus is complete resulting in two new nuclei |
| cytokinesis | cytoplasm and cell membranes complete their separation resulting in two separate cells |
Unlike mechanical sound waves that require a physical medium for propagation, light waves are electromagnetic and can travel through empty space. Light waves are also much faster, travelling at 186,000 m/s vs. 343 m/s for sound waves.
Secondary consumers (carnivores) subsist mainly on primary consumers. Omnivores are secondary consumers that also eat producers. Examples are rats, fish, and chickens.
Vitamins are necessary for a wide variety of bodily processes. Some vitamins like Vitamins A and C come from diet but others, like Vitamin D, are generated in response to sunlight.