Essential Idea:   Information stored as a code in DNA is copied onto mRNA.

• Outline answer to each objective statement for topic 7.2 (coming soon)
• Quizlet study set for this topic (coming soon)

At SHS, Topic 7.2 is taught in the following class unit(s):​​​​​​​​​

• ​​Transcription (unit 28a)
• Control of Gene Expression (unit 28b)

7.2.U1  Gene expression is regulated by proteins that bind to specific base sequences in DNA.

• Define gene expression.
• State two reasons why gene expression must be regulated.
• Outline the environmental regulation of the breakdown of lactose in E. coli.
• Outline the role of enhancers, silencers and promoter-proximal elements in regulation of gene expression.

7.2.U2  The environment of a cell and of an organism has an impact on gene expression.

• Describe the use of twin studies to measure the impact of environment on gene expression.
• Outline two examples of environmental influence on gene expression.

7.2.U3  Nucleosomes help to regulate transcription in eukaryotes.

• Outline the effect of methylation of nucleosome tails on rates of gene expression.
• Outline the effect of acetylation of nucleosome tails on rates of gene expression.

7.2.U4  Transcription occurs in a 5’ to 3’ direction.

• Describe the initiation of transcription, including the role of the promoter, transcription factors, the TATA box and RNA polymerase. 
• Describe elongation of transcription, including the role of nucleotide triphosphates and the direction of transcription. 
  
• Describe termination of transcription, including the role of the terminator.
  

 7.2.U5  Eukaryotic cells modify mRNA after transcription.

• List two major differences in gene expression between prokaryotic cells and eukaryotic cells.
• Describe the three post-transcriptional modifications of pre-mRNA in eukaryotes.

7.2.U6  Splicing of mRNA increases the number of different proteins an organism can produce.

• Describe the process of alternative RNA splicing.
• Outline an example of alternative splicing the results in different protein products.

7.2.A1  The promoter as an example of non-coding DNA with a function.

• Outline the role of promoter DNA.
  

7.2.S1  Analysis of changes in the DNA methylation patterns.

• State the effect of DNA methylation on gene expression.
• Compare methylation patterns in twins using superimposed images of dyed chromosomes.

7.2.NOS  Looking for patterns, trends and discrepancies- there is mounting evidence that the environment can trigger heritable changes in epigenetic factors.

• Define epigenetic and epigenome.
• List types of epigenetic tags.
• Discuss the role of reprogramming and imprinting on epigenetic factors.

In the News:

• Researchers discover how cells know their future and forget their past (2019-11-07)
  
• Scientists uncover the intricacies of the 'on/off switch' that creates cell differentiation (2019-08-08)
• Shedding light on darker parts of our genetic heritage (2019-07-19)
• Secrets of a sex-changing fish revealed (2019-07-10)
• What does it look like to “turn on” a gene? (2019-04-26)
• Study uncovers genetic switches that control process of whole-body regeneration (2019-03-14)
• Introns are mediators of cell response to starvation (2019-01-16)
• Finding the proteins that unpack DNA (2018-07-12)
• Alternative splicing is crucial to muscle mass maintenance (2018-08-10)
• The cartography of the nucleus (2018-06-08)
• How eye loss occurs in blind cavefish (2018-05-29)
• ​Scientists find missing factor in gene activation (2018-05-14)
• How turning down the heat makes a baby turtle male (2018-05-10)
• The Famine Ended 70 Years Ago, but Dutch Genes Still Bear Scars (2018-01-31)
• ​Genome architecture's surprising role in cell fate decisions (2018-01-16)
• Which sequences make DNA unwrap and breathe? (2017-12-05)
• Important mechanism of epigenetic gene regulation identified (2017-10-30)
• ​Human genomics: Cracking the regulatory code (2017-10-11)
• Gene activation therapy prevents liver damage in mice (2015-04-27)
• Error correction strategies of cells (2015-12-04)
• When the stadium is DNA, swapping one spectator may affect the results (2016-03-03)
• ​Gut microbes browse along gene buffet (2014-08-07)
• Stress alters children's genomes (2014-04-07)
• Epigenomics starts to make its mark (2014-04-02)
• How to build a Neanderthal (2014-04-17)
• Mom's diet right before pregnancy can alter baby's genes (2014-04-29)
• Mom's environment during pregnancy can affect her grandchildren (2014-07-15)
• Gene activity change can produce cancer (2014-07-25)
• Smoking mothers may alter the DNA of their children (2014-07-28)
• The 'memory' of starvation is in your genes (2014-07-31)
• High-fat diets raise risk of obesity in offspring (2016-03-14)
• Mechanical force triggers gene expression by stretching chromatin (2016-08-26)
• Cellular thermometer discovered (2012-07-12)
• Tiny, vast windows into human DNA (2014-09-01)
• Catching histones by the tail: A new probe to track histone modifications in living cells​ (2016-09-12)
• Patterns of RNA regulation in nuclei of plants identified (2014-12-31)
• ​Role of poly(A) tails in mitosis (2015-05-05)
• Highly sensitive and effective tool measures how your cells grow and divide (2016-07-28)
• How brain develops before birth is tightly controlled by RNA modification (2017-09-28)
• Alternative proteins encoded by the same gene have widely divergent functions in cells (2016-02-11)
• New research adds additional layer of complexity to human protein landscape (2016-02-26)
• Alternative splicing, an important mechanism for cancer (2017-09-21)
• How black truffles deal with jumpers in their genome (2014-07-30)
• Methylomic profiling implicates cortical deregulation of ANK1 in Alzheimer's disease (2014-08-17)
• Sperm and eggs carry genetic memories of parents' health well before conception (2014-08-18)
• Cancer leaves common fingerprint on DNA (2014-08-26)
• Epigenome: The symphony in your cells (2015-02-18)
• Massive project maps DNA tags that define each cell's identity (2015-02-18)
• ​Biological mechanism passes on long-term epigenetic 'memories' (2016-03-28)
• New understanding on how fundamental DNA sequences govern gene activity (2016-04-07)
• A mysterious method of gene control sheds its secrets (2017-01-12)
• Epigenetics between the generations: We inherit more than just genes (2017-07-17)

I give many of my IB Biology resources away, for the benefit of students and teachers around the world.  If you've found the materials helpful, please consider making a contribution of any amount to this Earthwatch Expedition Fund. 

​Did I forget something?  Know of a mistake? Have a suggestion?  Let me know by emailing me here.  Cheers!

Before using any of the files available on this site, please familiarize yourself with the Creative Commons Attribution License.  ​​It prohibits the use of any material on this site for commercial  purposes of any kind.  ​