Which characteristic would not be useful in a vector? a) a recognition sequence for a restriction enzyme b) large size relative to the host chromosomes c) the ability to replicate independently inside the host cell d) a reporter gene e) an origin of replication

The correct answer is B) Large size relative to the host chromosomes

Explanation:

A vector for clonation or expression must contain sequence elements which allow it independent replication and identification of host cells which have incorporated the vector. Among these elements are:

- Replication origin (option E): allows it to replicate independently of the host genome. Option B is the same as it.

- Restriction enzyme sites (option A): in order to cut the vector and to inser the desired gene into the vector.

- Reporter gene (option E): it allows to visualize the host cells which are expresing the inserted gene of the vector. For example, a reporter gene can codificate a fluorescent protein, thus the host cells which have expresion of the vector are fluorescent.

The only option which is unuseful is option B because if the vector has too large size, the transformation efficiency will be low. That means that fewer host cells will contain the vector after transformation.

the generally accepted parts of modern cell theory include: all known living things are made up of one or more cells. all living cells arise from pre-existing cells by division. the cell is the fundamental unit of structure and function in all living organisms.