Questions | 5 |
Topics | Cell Division, Geologic Time Scale, Health Benefits of Vitamins & Minerals, The Sun, Vibration |
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 |
The Earth is approximately 4.6 billion years old and its history is divided into time periods based on the events that took place and the forms of life that were dominant during those periods. The largest graduation of time is the eon and each eon is subdivided into eras, eras into periods, periods into epochs, and epochs into ages.
Vitamin / Mineral | Sources | Health Benefits |
---|---|---|
Calcium | Dairy products (milk, yogurt, cheese), spinach. | Aids bone growth and repair, muscle function. |
Iron | Red meat, beans, whole grains. | Allows red blood cells to transfer oxygen to body tissues. |
Magnesium | Nuts, whole grains, green leafy vegetables. | Muscle, nerve, and enzyme function. |
Potassium | Bananas, nuts, seeds. | Helps balance fluid levels in the body. |
Vitamin A | Liver, milk, eggs, carrots. | Vision, immune system, cell growth. |
Vitamin C | Green and red peppers, citrus fruits, broccoli. | Collagen formation, immune system function, antioxidant (helps protect cells from damage). |
Vitamin D | Exposure to sunlight. | Helps calcium strengthen bones, muscle, nerve, and immune system function. |
The Sun is a G-type main-sequence star (G2V) but is informally known as a yellow dwarf star. Composed of 73% hydrogen and 25% helium, the hot plasma that makes up the Sun reaches 9,900°F (5,505°C) at the surface. It formed approximately 4.6 billion years ago and makes up 99.86% of the mass in the solar system.
A vibrating object produces a sound wave that travels outwardly from the object through a medium (any liquid or solid matter). The vibration disturbs the particles in the surrounding medium, those particles disturb the particules next to them, and so on, as the sound propagates away from the vibration.