Answer: C) Centromeres
Explanation: Centromeres are involved in crossing over, none of the other ones are.
Any energy transformation involves the loss of some energy as B. Heat.
The answer is <span>The foreign DNA is placed in a biological vector for cloning.
After target genes are identified and isolated, they are usually inserted into a transfer factor. In the process of creating genetically modified crops, the transfer factor is plasmid (a circular DNA molecule) from a soil bacterium Agrobacterium tumefaciens. Therefore, the transfer vector in which the foreign DNA is placed is a biological vector. It is not artificially produced but isolated from the living bacterium.
</span>