mothernature

In humans, it sorta goes like this....

You are a diploid creature. You have 2 sets (di) of 23 chromosomes. One set was given by your dad (the sperm), one from mom (the egg). The egg and sperm are mono (one) ploid, meaning they have only one set of the 23 chromosomes each.

Now you have been given one set from each parent. This would be your genotype, everything your genetics are capable of. What is expressed (like you have blue eyes) is your phenotype. In your genotype, you carry the dominants (what is expressed) and the recessives (what is not expressed).

Eye color is a good example of this in humans. Dad has brown eyes, mom has blue. You are born with blue eyes. This means that mom has 2 genes for blue eyes. Dad has one gene for blue and one for brown. Brown eyes are dominant over blue. When a human has a gene for both colors, they will have brown eyes, when there is no dominant brown eyed gene, the result will be blue eyes. If you have blue eyes, then you received your dad's recessive blue eyed gene and you do not carry the gene for brown eyes.


Now we move to the plant kingdom, where it becomes way more complicated.

Any time a plant has more than 2 sets (diploid), it would be considered polyploid. In the realm of polyploidy, there are many sub-terms describing the exact situation. This is rare in animals, common in plants.

When trying to breed, the more sets of chromosomes, the harder to get the result you want. In a tetraploid (4), for example, there would be 1 expressed and 3 recessive. Then there is the dosage effect, and then I get lost.

There are several ways polyploidy is achieved. Through natural mutation, cross breeding, and chemical application. Sometimes the chromosomes don't all match up, but the plant still lives. These plants are usually sterile. Not all crosses will produce viable seed. Some species of plants creating a polyploid is an easy thing (Iris), some plant species, it is difficult or impossible (cannabis?)


There is also the phenomena of a 'sport'. This would be a mutated branch on an otherwise normal plant. I don't know why this happens. You usually see this in the horticulture world, but I don't see why it couldn't be in the rest of the plant kingdom as well.

The example of this would be the weeping white pine. Someone saw this in the wild, took cuttings, grafted them on to normal white pine root stock, and now every weeping white pine you see, is from the same original sport.

This would not be related to ploidy because a mutation could be as simple as 1 gene, on 1 chromosome, instead of entire sets of chromosomes.


Whew.....I need a nap.

tedkennedy

genetics luls

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matthew munari