19 Flashcards
Define homeobox genes
Regulatory gene that’s 180 base pairs long which code for the homeodomain
3 ways how are homeobox genes related to body plans
Initiated transcription
Switches genes in or off
Controls body plans
Define operon
Group of genes under the control of the same regulatory mechanism and are expressed at the same time
Define repressor protein
A protein that binds to the operator and affects the rate of transcription (blocks it as RNA polymerase can’t bind)
Describe homeodomain
Conserved 60bp section of all homeobox proteins that allows the protein to bind to DNA and act as a transcriptional regulator
Homeobox genes are
Highly conserved so little variation
Homeobox genes are found in which kingdoms
Plants
Animals
Fungi
Hox genes are a type of
Homeobox genes
Only present in animals
Hox genes code for
Proteins that act as transcription factors
Transcription factors do what
Bind to DNA to repress or activate genes to produce a particular protein
Hox genes are also
Highly conserved since fruit flies develop normally when swapped with chicken hox genes
Different hox genes are expressed where
Along the body, controlling body plan
Order of hox genes along chromosome
Is the order in which their effects are expressed
Hox genes also regulate what processes
Mitosis and apoptosis
Regulatory genes can be affected by what stresses
Internal stress e.g. hormones and psychological stress
External stress, e.g. change in light intensity or temp
