How Genes Are Controlled

What is one of the main concerns with cloning?


Clones are usually less healthy and shorter than the original. The cells in the clone are "older" than those of the originals'. They would be prone to diseases that are more commonly seen in older specimens, including obesity, pneumonia, liver failure and premature death

Why are calico cats only female?

In all female mammals, only one X chromosome is active in each cell. In cats, there is an X chromosome for black fur, and one for orange. In a female, one finds that if each X is a different color, different X's could be active, thus creating patches of orange and black.

Why do cloned specimens look and act different than their parent?


Cloning makes the offspring genetically the same as the parent, but appearance and behavior are largely environmental factors


The Facts:
-Cloning could provide an answer to endangerment
-The problem with cloning is that you are taking DNA that is already relatively old, and thus your clones have much older bodies
-The lac operon deals with lactose and allows for digestion
-The trp operon is made from E. coli
-Female mammals have two X chromosomes, one of which is inactive in each cell
-mRNA are broken down after they have created enough proteins
-Insect antenna are more similar to their leg parts
-In crustaceans, their mouth parts are homologous to their leg parts
-A DNA microarray is a glass slide with strands of DNA on it, each carrying thousands upon thousands of genes
-A signal transduction pathway is a series of molecular changes that coverts a signal on a target cell's surface to a specific response

Some Key Terms:
-Clone: An individual created by asexual means and genetically identical to the parent
-Gene Expression: The expression of genes into physical characteristics
-Differentiation: Individual cells becoming specialized in structure
-Histones: Small proteins packaged in the DNA
-Barr Body: The inactive X chromosome in a female
-Alternative RNA Splicing: A way by which an organism can get more than one type of polypeptide from a gene
-Homeotic Gene: Master control gene that regulates batteries of other genes and determine the anatomy of parts of the body
-Embryonic Stem Cells: "Blank" cells found in embryos that have the potential to become any type of cell
-Oncogene: A gene that could potentially make a cell cancerous
-Proto-Oncogene: A gene that has the potential to become an Oncogene

Diagram:

This is a diagram of reproductive and therapeutic cloning. You can see that you take the nucleus out of the cell you want to clone, remove the nucleus from your egg cell, and you'll eventually have the start of a clone. In reproductive cloning, these cells are put into a surrogate mother, in therapeutic cloning, these will be used in a tissue culture to be used in the organism.









Summary: 


This chapter, as the name suggested, talking about how genes are controlled and regulated. The first step in protein creation and control are the transcription factors that initiate the RNA polymerase. Silencers will repress protein production once finished. Keeping that in mind, only 1.5% of the human genome codes for proteins.

A Cool Video:


http://www.thedailyshow.com/watch/tue-march-27-2007/cloned-meat