Psychology Glossary. Genotype. The total set of genes contained within an organisms cells. Organisms contain some genes that are expressed (you can consider the expressed to mean that the gene is active or being used) and some that are not. Regardless, all the genes an organism has are considered the genotype.
Mars' closest approach to the Earth is called opposition, and occurs roughly every 780 days.
When Mars is in Conjunction the Sun is between Mars and Earth. Opposition, or when the Mars is on opposite side of the Earth from the Sun, will occur approximately 390 days after conjunction. At opposition the Earth and Mars will be nearly in a straight line from the Sun. The physical diameter of Mars is about 53% that of Earth and has a polar diameter of 4,195.7 miles (6,752.4 km) and an equatorial diameter of 4,220.6 miles (6,792.4 km).