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.
The distance to Mars from Earth varies as the planets orbit the sun. Every two years, they get as close as 55 million kilometers (34,175,400 miles). Space agencies time spacecraft launches to that planet to take advantage of such orbital alignments.