What essential criteria must be met in order to execute a successful mapping cross?

 Recombination must occur in the sex that displays genetic heterogeneity. The genotypes of the offspring must be readily determined from their phenotypes. One parent should be heterozygous and the other homozygous recessive for all the genes being mapped. One parent should be homozygous dominant and the other homozygous recessive for all the genes being mapped.

If you remove all the lions from the savanna it will lead to a increase of gazelle and a increase of cheetahs becasue of no competition