Chapter Eleven: How Genes are Controlled

1. What are histones?

  A: Histones are small proteins that help DNA packing by keeping the shape of the DNA.

2. What is gene expression?

  A: It is the overall process in which genetic information is transcribed from genes into proteins.

3. What do small RNAs do?

  A: Micro RNAs can bond to complementary sequences on RNA molecules as well as degrade mRNA or block its translation, giving them a part in gene expression.

Five Main Facts From The Reading:

1.Proteins interacting with DNA turn prokaryotic genes on or off in response to environmental changes.
2.DNA packing in eukaryotic chromosomes helps regulate gene expression.  
3.In female mammals, one X chromosome is inactive in each somatic cell.
4.Cascades of gene expression direct the development of an animal.
5.DNA micro-arrays test for the transcription of many genes at once. 

DNA Splicing. 

Gene Regulation Video: The Lac Operon: http://www.youtube.com/watch?v=oBwtxdI1zvk

Ten Key Terms:

 
1. Clone - an individual created by asexual reproduction.
2. Operon - a cluster of genes with related functions, along with a promoter and an operator.
3. Differentiation - an individual's cells become specialized in structure and function.
4. Homeotic gene - a master control gene that regulates batteries of other genes that actually determine the anatomy of parts of the body.
5. DNA microarray - a glass slide with thousands of different kinds of single-stranded DNA fragments fixed to it in a tightly spaced array, or a grid.
6. Nuclear transplantation - the technique used to achieve animal cloning.
7. Reproductive cloning - a type of cloning, which results in birth of a new individual.
8. Therapeutic cloning - when the major aim is to produce embryonic stem cells for therapeutic treatments.
9. Adult stem cells - cells that are able to give rise to many but not all cell types in the organism.
10. Oncogene - a gene, which can cause cancer when present in a single copy in the cell.

Summary: 

  This chapter talked about gene regulation and how the body manages to keep everything under control. It talked about specific enzymes that help regulate reproduction of certain proteins, such as the one that allows the digestion of dairy products.