44) why do neurons and some other specialized cells divide infrequently? ; a) they no longer have active nuclei.; b) they no longer carry receptors for signal molecules.; c) they have been shunted into g���.; d) they can no longer bind cdk to cyclin.; e) they show a drop in mpf concentration.

Fossils can only be formed when? if mud, silt or tar is in the area to preserve the fossil ierosion does not occur and allows the fossil to form oxygen and microorganisms cannot decay the bones the area is dry and does not contain mud or silt

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

Which of the following will a bacterium produce when a human gene is added to its genome? question 4 options: human carbohydrates a protein made up of both human and bacterial properties the human protein coded for by the human gene human plasmids that can be isolated from the bacterium