What are the two reasons why cell size is limited

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.

Anonnative species is best described as a species that a. does not normally live in an area b. has no permanent home c. is a poor predator d. increase biodiversity