D2.2 Gene Expression Flashcards
Identify which of the following is likely to increase the persistence of mRNA in a cell.
I. increased levels of nucleases
II. the presence of stabilising molecules
III. the addition of a poly-A tail
2 and 3 only
Identify the likely result of two genes sharing a promoter.
They are likely to be transcribed together.
May have related functions.
Enhancers are ________ of DNA that play a role in _____ when and to what extent a gene is expressed. They do this during _______.
specific regions, regulating, transcription
When an activator protein binds an enhancer, it forms a ____ that interacts with the promoter, making it easier for RNA polymerase to ___.
complex, bind
Epigenesis definition
process by which cells and organisms develop from an undifferentiated zygote through the interaction between DNA and environmental factors.
Which group added during methylation?
CH3 (methyl group)
Methylation of ________ in the DNA of a promoter represses transcription because it _____ transcription factors from binding.
cytosine, prevents
When can epigenetic changes can be inherited?
If they occur in germline cells
- or maintained through meiosis
What can affect the phenotype of cells and organisms.
diet, exposure to air pollution, temperature.
Hormone oestradiol.
I. It is a steroid hormone and so is able to move freely through cell membranes.
III. Once bound to a receptor, it can move into the nucleus and bind directly to DNA, modifying gene expression.
monozygotic twins.
genetically identical individuals; useful for studying the effect of the environment on gene expression.
