Gene Rearrangement and Evolution

[mschristine]

Clear this up for me: To say genes rearrange in a cell is to say a person's DNA changes.

True or false?

Also, can someone give me some info on "jumping genes"? I've been trying to decide if they really are a factor in evolution. I want to make sure I have this straight: Certain genes called jumping genes respond to environmental or internal stress by moving to other parts of DNA. These other parts are usually active genes. Sometimes they cause a gene to turn off though. Does this happen regularly to human DNA?

[Jesse2504]

The overall DNA content does not change, although with "jumping genes" (Transposons) mutations can occur and change the DNA.

Whether or not changing the sequence of genes in DNA is classed as changing the DNA would depend on the functionality of the sequence. Since I am not 100% sure whether changing the sequence would effect the functionality of proteins transcribed and translated from the DNA, I cannot say whether we would formally call it a different molecule of DNA. Chemically speaking, it would be a different molecule since you cannot superimpose each onto the other but I'd imagine the functionality of the molecule would determine the classification biologically.

"The most common form of transposon in humans is the Alu sequence. The Alu sequence is approximately 300 bases long and can be found between 300,000 and a million times in the human genome."

Transposition may result in the inactivation or changes in gene expression at the site of expression.

There's a few things to go look at further. Not sure if genes turn off regularly in humans.