31. What is the role of cyclins in a cell? A. to control the movement of microtubules
B. to signal for the cell to divide
C. to stimulate the breakdown of the nuclear
membrane
D. to cause the nucleolus to disappear

thermophiles, notice the prefix thermo.

he movement of air through earth's or any planet's atmosphere is called wind, and the main cause of earth's winds is uneven heating by the sun. this uneven heating causes changes of atmospheric pressure, and winds blow from regions with high pressure to those with low pressure.

i hope this : )

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.