Which cell stucture is responsible for the passage of material into and out the cell

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

When an object is moving away from you while still making a sound, the pitch of the sound is perceived to a. lower b. unchanged c. fluctuating d.higher

In which order does sexual reproduction take place in plants? a. pollination, germination, fertilization b. germination, fertilization, pollination c. pollination, fertilization, germination d. fertilization , pollination, germination