BB 7 - Epigenetics Flashcards
Why are genes expressed?
To produce products such as proteins through the processes of transcription and translation.
What do genes give rise to?
Phenotypic expression, which is the observed features in a cell or organism.
What is a phenotypic expression?
A physical, biomechanical, or physiological characteristic.
How can phenotypes be regulated or altered?
By controlling transcription or translation.
What are transcription factors?
Proteins that bind to specific DNA sequences in the promoter region of a gene and either increase or decrease gene expression
(ie: regulate gene expression)
How many transcription factors are there?
Two
What are the two types of transcription factors?
Repressors and Enhancers (activators)
How do repressors function in transcription?
Bind to the promoter and block other transcription factors or RNA polymerase.
Decreases gene expression.
How do enhancers function in transcription?
Bind to the promoter and recruit RNA polymerase to begin transcribing the gene.
Increases gene expression.
How many genes are in the human genome?
25,000
What does every cell in the body have except for gametes?
Exact same genetic code (DNA)
How do cells differentiate?
Through stem cells which specific transcription factors switch on specific genes.
How does differentiation occur?
Through gene expression.
How can the expression of some genes be affected?
By environmental factors
Gene expression can be changed in how many ways?
Two
