1) Flight paths 
vectors 1. Things physical; such as, forces which have size and direction. 2. Insects or animals which carry diseases from one animal or plant to another.
Self-replicating DNA molecules that can be joined with DNA fragments to form recombinant DNA molecules.
Vectors are living organisms that can transmit infectious pathogens between humans, or from animals to humans. They are transmitted by bloodsucking insects like mosquitoes or ticks which take the disease from one host and transfer it to another.