24 notocords is restricted to tregon
a) hemichordates
c) cephalochordates
d)all chordates

Me with these questions image attached

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.