Chromosome Number in Species Number of Chromosomes Human Homo sapiens 46 Chimpanzee Pan troglodytes 48 Domestic Dog Canis familiaris 78 Asian Rice Oryza sativa 24 Round Worm Parascaris equorum 2 Chromosome Number in Species Species have different numbers of chromosomes than other species

Chromosome Number in Species Number of Chromosomes Human Homo sapiens 46 Chimpanzee Pan troglodytes 48 Domestic Dog Canis familiaris 78 Asian Rice Oryza sativa 24 Round Worm Parascaris equorum 2 All eukaryotic species have at least two chromosomes. Why? They come in homologous PAIRS

Chromosome Number in Species The number of chromosomes in a species has no specific significance nor does it indicate any relationship between two species. They come in homologous PAIRS

Estimated Number of Genes Species Number of Chromosomes Estimated Number of Genes Human Homo sapiens 46 23,000 Chimpanzee Pan troglodytes 48 Domestic Dog Canis familiaris 78 19,000 Asian Rice Oryza sativa 24 45,000 Round Worm Parascaris equorum 2 20,000 The number of chromosomes does NOT correlate to the number of genes They come in homologous PAIRS

Chromosome number can change *A rare event in evolution *May lead to the formation of a new species

Chromosome Splitting

Chromosome fusing