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.

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.

Like carbohydrates, fats provide energy to the body. The difference is energy from fats tends to be longer burning as opposed to the quick fuel provided by carbohydrates. Fats come in three types, saturated (meats, shellfish, eggs, milk), monounsaturated (olives, almonds, avocados), and polyunsaturated (vegetable oils). Saturated fats can raise LDL ("bad") cholesterol while unsaturated fats can decrease it.

Newton's law of universal gravitation defines gravity: All objects in the universe attract each other with an equal force that varies directly as a product of their masses, and inversely as a square of their distance from each other. Expressed as a formula: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) where r is the distance between the two objects and G is the gravitational constant with a value of 6.67 x 10^-11.

The Earth's atmosphere has several layers starting with the troposphere which is closest in proximity to the surface. Containing most of the Earth's breathable air (oxygen and nitrogen), it's a region with warmer temperatures closer to the surface and cooler temperatures farther away which results in the rising and falling air that generates weather.