Gene flow is the movement of genes between different populations. which of these would not be a barrier to gene flow?
a) oceans
b) big deserts
c) large mountain ranges
d) natural bridges connecting islands

Natural bridges connecting islands would NOT be a barrier to gene flow

Gene flow is the transfer of genetic variation between different populations. Mobility plays an important role in gene flow   between different populations. Natural bridges connecting islands would not be a barrier to gene flow because with natural bridges, there would be movement of organisms. Impassable mountain ranges, big deserts, oceans or man- made barriers are examples of barriers to gene flow.

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.