PART 2 How do index fossils help scientists establish how old rocks and other fossils are? In your answer, include fossils in the same layer of rock, in a lower layer of rock, and in a higher layer of rock compared to an index fossil.

1. describe the structure and function of the specialized cells you observed in the video. 2. research the types of cells present in the kidney.

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

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.