How do spectrographs help astronomers classify stars? They determine the size of stars.
O They evaluate the color of stars.
O They measure the brightness of stars.
O They analyze the composition of stars.

What processes take place before the mature mrna exits the nucleus?

An animal cell (left) and a plant cell (right) are shown.which organelle, labeled x in the diagram, is found in both plant and animal cells?

Astudent poured a solution of bromothymol blue indicator into three test tubes. then he placed an aquatic plant in two of the test tubes, as shown below. he placed a stopper on each test tube and placed them all in the dark for 24 hours. bromothymol blue turns from blue to yellow in the presence of co2