Genetics Lab

Genetics

My children look nothing alike. They have the same parents. The same genetic material went into each one. Genetics explains how traits like these and ones you can't see are passed or not passed from one generation to the next.

publications.nigms.nih.gov/.../ch1_dnagenes.jpg

Dragon Genetics

In this lab, different chromosomal allels are selected in the make-up of the second dragon until the identical twin of the first is acheived. By manipulating which recessive and dominate alleles are present in the bottom dragon, we are able to bestow horns or remove them, give him wings or ground him with or without a leg to stand on . . . It's easy to understand how certain traits are more common than others when you consider that legless and wingless dragons can't run away from hungry pedators. The stronger, faster, and more attractive dragons would have more opportunity to reproduce.

http://www.intarttiles.com/

Every cell in our body has the complete gene sequence present in our DNA. When our cells prepare for sexual reproduction, they go through a special process of reduction division called Meiosis. This reduces the number of chomosomes by half in the daughter cells. When these cells develop into an egg and are fertilized by a sperm (carrying the other half of needed chromosomes) a zygote containing 23 pairs of or 46 chromosomes is created. This brings diversity to the table - we are not carbon copies of our parents (although, as I age, I do see more of my mother in the mirror - another story . . .)

Punnett Square - Scenario 5

The Punnett Square (monohybrid cross) is a tool by which we can ascertain the odds of passing along traits or disorders. The mother and father's genotypes are placed along the top and side of the square with the cross-refrenced results posted in the squares inside the box. From that, we are able to tell what the odds are that the trait in question will be passed on to the child. These odds do not change with multiple births. When reviewing a single trait, the odds are broken down no farther than 1/4. When two traits are being considered, a dihybrid cross produces 4 possible phenotypes with a probability as low as 1/16.

Terms to know:

• Genotype - the method of labeling what genes are present in each individual. Some are dominate, some recessive. These determine what attributes you will inherit from your parents. The genotype is what we manipulated to change the features of the dragon.


• Phenotype - the physical expression of the genotype. As an example, the wings on some of the fruit flies were short as a result of the genotype they inherited. Your eyes are a certain color because of the genotype allel you inherited.


• Allel - the same location of a gene that addresses the same trait on a pair homologuous chromosomes that can vary in attributes.


• Cross - a tool used to predict probability of traits.


• Dominant - used to describe the gene that will express itself when present in a genotype.


• Recessive - a gene when paired with a dominant won't be evident in the phenotype, but can still carry traits to another when paired with another recessive.

Now we know why so many differences are evident in my kids.

The science of genomics and genetic engineering is a burgeoning field. Understanding how the replication of everything works has huge, unimaginable potential for great advances in medicine and agriculture or any field involving living things; however, just as huge is the unkown factor pertaining to how these changes will affect homeostasis on our planet as we know it.