Answer:
An organism which has two different alleles of the gene is called heterozygous. Phenotypes (the expressed characteristics) associated with a certain allele can sometimes be dominant or recessive, but often they are neither.
He used Selective Breeding
High water floods &- volcanic eruptions
Variations are beneficial for the survival of the species. Populations of organisms fill well-defined places, or niches, in the ecosystem, using their ability to reproduce.However, if some variations were to be present in a few individuals in these populations, there would be some chance for them to survive.
The color of a star is primarily determined by its surface temperature.
For example, the really hot stars, called White Dwarf stars, have a white surface temperature, while a cooler star would have a more red color.
