Answer:
Regulatory sites e.g enhancers and silencers
Explanation:
Gene expression involves the synthesis of gene products usually proteins and RNA. However, a certain product might not be needed at all or in small quantity. Gene regulation mechanism is the process that makes this happen. Gene regulation is the mechanism that acts to induce or repress the expression of a gene.
Gene regulation involves controlling the rate and manner of gene expression which is achieved through a set of regulatory proteins called transcription factors. Transcription factors bind to specific regulatory nucleotide sequences and help to turn "on or off" specific genes in the DNA.
Transcription factors can either be ACTIVATORS or REPRESSORS depending on whether they boost or inhibit gene expression. The binding sites for these regulatory proteins called TRANSCRIPTION factors are the regulatory nucleotide sequences on the DNA called enhancers and silencers.
The correct answer is a cell membrane. Prokaryotic cells do not have a true nucleus or membrane bound organelles, so that eliminates the other answers.
Answer: Energy Source
Explanation:
An electric force field is provided by an energy source such a cell or a battery. A potential difference is created when a conducting wire is connected across the two terminals of the battery. This creates an electric force field which pushes the electrons from one towards the another. The flow of electrons constitutes an electric current.
A,B and AB.
Bloodtype B is OB , so there are three possible blood types for their offsprings. The only exlusion is O type.