2. pertaining to or emanating from focus. focal distance. see focal-film distance. focal length. the distance between the lens and an object from which all rays of light are brought to a focus. focal liver disease. widely disseminated micro-abscesses or abscesses, migration paths of helminth larvae.. pertaining to or emanating from focus. focal distance. see focal-film distance. focal length. the distance between the lens and an object from which all rays of light are brought to a focus. focal liver disease. widely disseminated micro-abscesses or abscesses, migration paths of helminth larvae.
The kilogram or kilogramme (SI unit symbol: kg) is the base unit of mass in the International System of Units (SI) (the Metric system) and is defined as being equal to the mass of the International Prototype of the Kilogram (IPK, also known as Le Grand K or Big K).
A kilobase (kb) is a unit of measurement in molecular biology equal to 1000 base pairs of DNA or RNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 10 37, and weighs 50 billion tonnes. In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC (trillion tons of carbon).