We all have two alleles, or versions, of each gene. Being hom0zygous for a particular gene means you inherited two identical versions. It's the opposite of a heterozygous genotype, where the alleles are different. People who have recessive traits, like blue eyes or red hair, are always hom0zygous for that gene.
Polar bears are listed in red as they are belong to Endangered Species. These species are gonna extincting due to gradual changes by environmental factors.
