How do scientists define the segments of the geologic time scale?
a. the scientists study fossils in rock layers to find major changes
b. the scientists use fixed amounts of time for each segment
c. they do both of these
d. they do neither of these

Dr. bad has developed a way to damage the atp-binding cassette transporter (abc transporter) on a cell. the cell's abc transporter can no longer bind and use atp when it's transporting substances. which of the following statements best describes how this damage would effect the transport of substances in the affected cell? (choice a) substances at a low concentration outside the cell would be more rapidly transported into the cell, where there is a high concentration. (choice b) substances at a high concentration outside the cell would not be transported into the cell, where there is a low concentration. (choice c) equilibrium would be established between all substances inside and outside of the cell. (choice d) substances at a low concentration outside the cell would not be transported into the cell, where there is a high concentration.

To maintain asepsis when administering an injection, all parts of the syringe can be handled except the:

Approximately what portion of the foods that we eat have been genetically modified in some way? a.fewer than 10% b.about 50% c.nearly 100%