What type of mutation occurred in the dna sequence?

a.
duplication
b.
deletion
c.
addition
d.
substitution

Wind energy is plentiful in regions with vast open spaces it is a non polluting renewable resource what could be an economic factor that makes the use of this resource less feasible then non renewable resource even in such regions

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.

Ascientific idea becomes valid when it is what?