Heterozygous means 2 things are different, aka not both are the same, which in this case is genes. Genes are represented by letters, in this example lets use the letter Bb.
B=dominant gene
b=recessive gene.
Lets use human eye color as an example. The dominant gene "B" stands for brown eyes. The recessive gene "b" stands for blue eyes. Now, you get two genes, one from each parent. Now, my mother has brown eyes, and that goes back several generations, so i know that she is "homozygous" for brown eyes (BB). (Homozygous means 2 of the same thing). My father has blue eyes, and because he has blue eyes im 100% sure he is homozygous for blue eyes (bb). I am therefore a het! i am heterozygous for brown eyes (Bb). I have brown eyes, because the brown gene is the dominant gene, but i also carry the recessive gene for blue eyes.
You can learn alot just by looking at a punnet square:
B B
b Bb Bb
b Bb Bb
Moms genes: BB (top)
Dads genes: bb (left side)
My genes: Bb (center)
The center 4 combinations (all are Bb in this case due to this particular example) is the percentage of my parents having hets as babies. Each of the 4 represents a 25% chance of an offspring's genes. Since all 4 are the same it is a 100% chance. Therefore i know that i am a het, and not homozygous, for brown eyes.
Hope i helped
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Leopard Geckos
African Fat Tailed Geckos
Last edited by -okapi-; 11-15-05 at 09:31 PM..
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