What is it called when a cell doesn't have a nucleus?

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?

Dna replication or repair occurs in a cell in all of thw following situations except when

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures