Prokaryotes.
I hope this helps!!
Answer:
A) they help transport some substances through the membrane.
Explanation:
The membrane proteins that span the bilayer of phospholipids help in the transport of polar, large and charged substances across the membrane. The nonpolar core of the membrane does not allow these charged and polar substances to pass through. Proteins serving as channels form pores to allow movement of the specific substances.
On the other hand, carrier transport proteins of the membrane bind to the substances present at one side of the membrane and deliver them to the opposite side.
<h2>Answer:</h2>
Bacteria provide genetic engineers with <u>_vector_ </u>and <u>_host_.</u>
<h3>Explanation:</h3>
Vector are vehicles or carriers which are used to carry the gene of interest. They are usually plasmids which are bacterial circular genome which can replicate independently.
Hence bacterial plasmids are used for the insertion of gene of interest and its transfer to the host cell.
As plasmids is taken from the bacteria, so mostly bacteria is used as the host for the gene of interest.