When E. coli is grown on glucose, and there is no lactose available
A) lactose molecules bind to the lac repressor.
B) the lac repressor binds to the operator of the lac operon.
C) RNA polymerase binds to the promoter of the lac operon.
D) the lac genes are transcribed into messenger RNA.

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.

The carrier molecules of the electron transport system are located in the