Answer:
Biodiversity is the variety and variability of life on Earth. Biodiversity is typically a measure of variation at the genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near the equator, which is the result of the warm climate and high primary productivity.
Explanation:
the number of trophic levels in a food web
Theory because a theory is a well substantiated explanation of how a particular phenomenon works based on the set of facts which had been repeatedly confirmed through observations and experiments. A scientific theory gives reliable account of a phenomenon.
The sun appears to cross the plane of Earth's equator
when it reaches either one of the "equinox" points in the sky.
Fossils up to 75,000 years old can be dated with Carbon-14.
Radio isotopes can be used for the age determination of the fossils. Carbon-14 is a common isotope which is used for that purpose. But the half- life of the Carbon-14 is relatively small as 5730 years. That means the amount of Carbon-14 will be half after every 5730 years. Hence, decay is very fast. So Carbon-14 cannot be used forage determination which is more than 75000 years due to the low accuracy.
The term is normally applied to a group of between six and nine elements (boron, silicon, germanium, arsenic, antimony, tellurium, and possibly bismuth, polonium, astatine) found near the center of the P-block or main block of the periodic table.