Controlling Gene Expression
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Controlling Gene Expression - Leaderboard
Controlling Gene Expression - Details
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20 questions
| 🇬🇧 | 🇬🇧 |
| What does a mutagenic agent such as high energy ionising radiation do? | It can increase the rate of mutation |
| What effect does a deletion, addition, or duplication have on the DNA base sequence? | Produce a frame shift. |
| What are totipotent stem cells? | Cells that have the ability to differentiate into any type of cell. |
| How are pluripotent stem cells different from totipotent stem cells? | They can differentiate into all cells apart from those of the placenta |
| What is the source of totipotent stem cells? | Human embryos |
| What are iPS cells? | Induced pluripotent Stem Cells that have been genetically engineered from unipotent stem cells. |
| What is transcription? | The first stage of protein synthesis in which messenger RNA is produced from an exposed DNA sense strand. |
| What is the complex of proteins called that induce transcription after the move into the nucleus from the cytoplasm. | Transcription Factors |
| What enables the transcription factor to bind to the correct region of DNA? | A complementary binding site. |
| The presence of the female hormone oestrogen can enter a cell and instigate transcription - how does it enter the cell? | As it is a lipid-soluble, steroid hormone, it can easily diffuse through the phospholipid bi-layer of the plasma membrane. |
| When an oestrogen molecule binds to a TF, what happens to effectively "switch-on" transcription? | The binding site will change shape to make it complementary to the specific region of DNA so transcription can commence. |
| A DNA-Histone complex forms chromatin i.e. "unraveled" DNA. in the cell nucleus. What are histones? | Proteins |
| What is the result of increased acetylation of histone proteins? | Looser, less condensed DNA with easer access to DNA for transcription factors. |
| What is the result of increased Methylation of DNA? | Tighter, more condensed DNA with reduced access to DNA for transcription factors. |
| As epigenetic changes can activate or silence specific genes, it follows that the protein enzymes that are key in methylation and acetylation provide a potential target for drug development. How could increased methylation result in tumour development | Increased methylation could result in reduced activity of tumour suppressor gene, leading to increased, uncontrolled cell division. |