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This is a preparatory explanation of concepts for the next article which will be ‘Dominant and Recessive Traits in Liliums and their Role in Practical Hybridizing’ by Joe Hoell.
To understand the effects and importance of dominant and recessive genes, it is necessary to understand a bit about the process by which plants and cells within those plants divide and multiply. There are two processes, the process called meiosis, the division which produces the sex cells (gametes), and the process which causes cells to multiply and increase in number, thereby making the plant grow. This process is called mitosis.
It is estimated that there are 70,000 to 100,000 genes on a single strand of DNA. Each DNA has two strands that are joined at a spot called the centromere, and they resemble a spiral or helix [a "twisted ladder effect" ED].
A diploid lilium has 24 chromosomes; each chromosome has one DNA helix.
Each male or female reproductive cell (gamete) of a diploid lilium has 12 chromosomes.
The process which produces cells with only 12 chromosomes is called meiosis.
A normal cell contains two copies of each chromosome, 24 in all for a lilium. Meiosis is a two stage process, the first allows for mixing of genetic material, the second produces cells which have half the number of chromosomes of the diploid or normal cell.
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