|Topics||Carbon Cycle, Circulation, Curved Lenses, Curved Mirrors, Filtering Air, Health Benefits of Vitamins & Minerals, Prefixes, Refraction, Scavengers, Stomach|
The carbon cycle represents the ciruit of carbon through Earth's ecosystem. Carbon dioxide (CO2) in the atmosphere is absorbed by plants through photosynthesis. Plants then die and release carbon back into the atmosphere during decomposition or are eaten by animals who breathe (respiration) the carbon into the atmosphere they exhale and produce waste which also releases carbon as it decays.
Like the respiratory system, the circulatory system serves to transport oxygen throughout the body while removing carbon dioxide. In addition, the circulatory system transports nutrients from the digestive system.
Unlike curved mirrors that operate on the principle of reflection, lenses utilize refraction. A convex lens is thicker in the middle than on the edges and converges light while a concave lens is thicker on the edges than in the middle and diffuses light. A common use for curved lenses is in eye glasses where a convex lens is used to correct farsightedness and a concave lens is used to correct nearsightedness.
A concave (or converging) mirror bulges inward and focuses reflected light on the mirror's focal point where the mirror's angles of incidence converge. In contrast, a convex (or diverging) mirror bulges outward and diffuses the light waves that strike it. A common use of a concave mirror is in a reflecting telescope, a common use of a convex mirror is in the side view mirror of a car.
After air enters through the nose, it passes through the nasal cavity which filters, moistens, and warms it. Further filtering takes place in the pharynx, which also helps protect against infection, and then in the trachea which is just past the epiglottis, responsible for preventing food from entering the airway.
|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.|
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:
Because different materials have different refractive indices, light changes speed when passing from one material to another. This causes the light to bend (refraction) at an angle that depends on the change in refractive index between the materials. The greater the difference, the higher the angle of refraction.
Like decomposers, scavengers also break down the dead bodies of plants and animals into simple nutrients. The difference is that scavengers operate on much larger refuse and dead animals (carrion). Decomposers then consume the much smaller particles left over by the scavengers.
Food is mixed with gastric acid and pepsin in the stomach to help break down protein.