What structure regulates the amount of light passing to the visual receptors of the eye?

In which of the following ways is the function of the surface of a microsphere similar to the function of an actual cell membrane? a.both make it possible for the conditions in the interior to be different from the conditions outside. b.both provide a barrier that keeps water from flowing across it so the interior remains dry. c.both separate the rna that forms in the interior from any rna that might form in the environment. d.both can actively move molecules into the interior or out into the surrounding environment.

Which plant has a visible leaf modification that will it conserve water in extremely dry environments?

How many copies of each chromosomes should be present in each of the 4 final haploid versions of gamete?