Anti-evolutionary thinkers sometimes argue that natural selection could not produce a
complex structure like the vertebrate eye. They claim that all of the parts of the eye
must have arisen at once, asking why natural selection would favor the development of
part of an eye that is not yet capable of forming a focused image. Which of the
following statements is consistent with a survey of eye structure in the molluscs?
A) The argument has a great deal of merit. Only full-blown image-forming eyes are
present in modern organisms.
B) There are many intermediate stages of eye complexity that fulfill different adaptive
functions.
C) The vertebrate eye is the ancestral form, and other types of organisms have
degenerate eyes that have lost most of their original structure and function.
D) The vertebrate eye works in a way that is completely different from the eyes found
in molluscs and other invertebrates.
The envelope of a mumps virus
A) helps the virus enter the cell.
B) is coded by host genes.
C) helps the virus insert its DNA into the host cell genome.
D) accounts for viral resistance to antibiotics.