Hundreds of years ago, it was believed by many that our solar system was Geocentric. This means that Earth is at the center of the solar system, with the Sun and other planets orbit around it. Today, the solar system is now thought to be Heliocentric. What does this mean?

This means that Earth is at the center of the solar system, with the Sun and other planets orbit around it. Today, the solar system is now thought to be Heliocentric.

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.