In the Mexican swordtail fish, the wild-type color is olive-green. Other color variants include golden and Take caution with ratio there is some reduced viability in this system. Matings involving fish of these three phenotypes are shown below: Explain the inheritance of these color phenotypes in the fish Solution At any rate, the mode of inheritance of albinism in the goldfish has not hitherto been known. Using mates of different varieties of the goldfish, scientists arrived at the conclusion that albinism of the goldfish is not a simple Mendelian character but it is represented by the double homozygote of two non-linked autosomal recessive genes since because the F2 generation shows 15:1 ratio for non-albino and albino types like we see in the case of duplicate genes. example: If the animal was A/a, because a is recessive and A is dominant, the animal\'s phenotype wouldn\'t be albino, but it would still carry the gene for albinism (since it has an \"a\"). Since it carries both \"A\" and \"a\", it is known as \"heterozygous\". If the animal had the A/A combination, its phenotype wouldn\'t be albino, and it wouldn\'t carry the gene for albinism (both genes being the same, it is called \"homozygous\" for \"A\"). If it were homozygous for \"a\" (i.e. a/a), the animal\'s phenotype would be albino. Since \"a\" is recessive, both alleles need to be \"a\" in order for albinism to be expressed in the phenotype. The genes for the pigment cells are inherited independently of one another, and there is no known linkage to any other genes. So, each pigment type is coded by two different genes, one on each of a pair of chromosomes. The phenotype of wild type animals is dark, non-melanoid, non- albino and non-axanthic. The golden colour (D/D a/a or D/d a/a). It has normal migration of pigment cells, but lacks melanophores, hence the yellow/gold appearance..

1. In the Mexican swordtail fish, the wild-type color is olive-green. Other color variants include
golden and Take caution with ratio there is some reduced viability in this system. Matings
involving fish of these three phenotypes are shown below: Explain the inheritance of these color
phenotypes in the fish
Solution
At any rate, the mode of inheritance of albinism in the goldfish has not hitherto been known.
Using mates of different varieties of the goldfish, scientists arrived at the conclusion that
albinism of the goldfish is not a simple Mendelian character but it is represented by the double
homozygote of two non-linked autosomal recessive genes since because the F2 generation shows
15:1 ratio for non-albino and albino types like we see in the case of duplicate genes.
example: If the animal was A/a, because a is recessive and A is dominant, the animal's
phenotype wouldn't be albino, but it would still carry the gene for albinism (since it has an
"a"). Since it carries both "A" and "a", it is known as "heterozygous". If the animal had the
A/A combination, its phenotype wouldn't be albino, and it wouldn't carry the gene for albinism
(both genes being the same, it is called "homozygous" for "A"). If it were homozygous for
"a" (i.e. a/a), the animal's phenotype would be albino. Since "a" is recessive, both alleles need
to be "a" in order for albinism to be expressed in the phenotype.
The genes for the pigment cells are inherited independently of one another, and there is no
known linkage to any other genes. So, each pigment type is coded by two different genes, one on
each of a pair of chromosomes. The phenotype of wild type animals is dark, non-melanoid, non-
albino and non-axanthic.
The golden colour (D/D a/a or D/d a/a). It has normal migration of pigment cells, but lacks
melanophores, hence the yellow/gold appearance.