Answer:
A promoter is a region of DNA where transcription of a gene is initiated.
Explanation:
Promoters are a vital component of expression vectors because they control the binding of RNA polymerase to DNA.
Hope this helps and sorry if this is too late!
Answer:
oxygen enters blood cells by 'diffusion'
This is not biology but i can probably help so get the surface area, then get the volume. and divide this is usually how ratios work, leave it a fraction, simplify if necessary
Your answer is gonna be the first second and fourth options