1.1 The Cell, DNA & Genes
The basics of genetics are common to all species. The colour genetics of parrot species are strikingly similar. I originally wrote this for a budgerigar group and therefore many examples involve budgies but what is discussed here applies equally well to love birds, cockatiels, Indian Ringnecks, Alexandrines and even to Macaws, Eclectus and Greys and many more.
In this section we will present some basic definitions and lay the foundation on we which we will build the future concepts.
A cell is the building block of life. All living organisms, both animal and plants, are made up of cells. If we compare the whole living organism to a building, a cell can then be compared to one brick in that building.
Every Cell in the body contains DNA. DNA contains the genetic information about the organism. We again take the example of a building. Imagine that each brick in the building contains a document; A building plan of the whole building with every possible detail. The number of floors, layout of each floor, position of every window, size of every window, what it is made of and so on. The DNA of an organism is like this building plan. So in a bird every cell contains the complete information about that bird. The sex, body size, colour, feather quality and all other genetic characteristics are encoded in the DNA of the bird.
A gene is a distinct portion of a the DNA. So if the DNA is the complete building plan, one gene is like a small section of this plan that deals with one feature of the building. For example a section in the plan on windows tells us the shape, size and material of the windows. For a bird one gene may contain information about the color another about the size and yet another about the pattern on the bird. Several genes together may control what we see as a single feature. We will study this in detail later on.