Questions | 5 |
Topics | Cambrian Period, Convection, Geologic Time Scale, Health Benefits of Vitamins & Minerals, Infiltration |
The Cambrian period is one of the most significant geological time periods. Lasting about 53 million years, it marked a dramatic burst of changes in life on Earth known as the Cambrian Explosion. It is from this period that the majority of the history of life on Earth, as documented by fossils, is found. Called the fossil record, the layering of these mineralized imprints of organisms preserved in sedementary rock have allowed geologists to build a historical record of plant and animal life on Earth.
Convection is the transfer of heat by the circulation or movement of the heated parts of a liquid or gas. Examples of heat transfer by convection include water coming to a boil on a stove, ice melting, and steam from a cup of coffee.
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 water then accumulates as runoff and eventually returns to bodies of water or is absorbed into the Earth (infiltration) and becomes part of the water table, an underground resevoir of fresh water.