![]() ![]() L/+ X L/+ produces the following percentages. Thus if we mate two variegated birds together. chromosome and a gene for lipochrome on the other.Ī green bird has the normal genes on each chromosome…Īll living things pass their chromosomes onto their offspring. A variegated bird has a gene for lipochrome on one. L/+ or +/L is the genotype of a variegated bird. Here we have a gene for lipochrome on each chromosome. L – denote lipochrome, the mutated variety. + – denotes melanin, the wild, normal type. ![]() This knowledge allows us to figure out what varieties of young any pairing will produce. If both genes are for melanin, the bird will be dark. If it has one gene for lipochrome and one for melanin production, it will be variegated. If a bird possesses two genes for lipochrome, it will be a clear canary. This mutation is classified as an incomplete dominant. The production of melanin is defective in the lipochrome, clear canary. Melanin is deposited in the feather giving the green phenotype. The wild canary produces melanin, the chemicals that cause the dark colors in the feather, from the proteins in its food. Charting all the possible combinations, we can then list the probability of any particular color being in the nest. We count all the single genes that come from the father, and all the single genes that come from the mother. Knowing the genotype of any pair of birds, knowing what genes they are showing and what genes they are carrying, that they are split for, allows us to predict the appearance of the young. Thus each nestling receives a set of genetic material from its father, and a set from its mother. When the egg is fertilized by the sperm cell, in the resulting fertilized egg, or zygote, the single strands combine to form a pair. These cells divide, evenly parting the genetic material, generating reproductive cells. These single strands are produced from cells with the usual double strands. The unfertilized eggs in the hen and the sperm cells in the cock bird contain single strands of chromosomes. ![]() The reproductive cells are an exception to the rule that chromosomes are found in pairs. How the genes interact with each other is the subject of genetics. Imagining any particular spot, two possibilities exist: both are the same or they are different. On each chromosome of the pair are spots that, together, control some aspect of the organisms health or physical makeup. When viewed under a microscope, the chromosomes are seen to be pairs of tiny strings. The chromosomes are the genetic blue prints of living things. ![]() Within cells are located pairs of chromosomes. The genotype tells us why a particular specimen has a certain appearance and what traits it is carrying.Īll living things are composed of cells. Knowing the genotype allows us to compute what color nestling any particular bird can produce. One must know either the ancestry of an individual, or do test matings in order to know the genotype. The genotype of an organism is its genetic description. When we describe a bird as white, yellow, red or variegated, we are defining its phenotype. The phenotype of a living thing is simply its appearance. Some knowledge of genetics is needed to understand the production of the different canary colors. The yellow, white, red ground, and mosaic canaries are all clear, lipochrome mutations. The lipochrome birds are completely devoid of dark color. Green, blue, pastel, brown, isabel, agate, opal, topaz, ino, and satinette canaries are all melanin. The original wild canary was of the melanin variety. The COLOR BRED canary is classified into two divisions: melanin and lipochrome. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |