Which of the following best describes the function for the organelle labelled ‘d’?
(a) moves substances across the cell membrane
(b) transports materials around the cell
(c) controls all cell activities
(d) packages materials for export from the cell

The dna in a cell’s nucleus encodes proteins that are eventually targeted to every membrane and compartment in the cell, as well as proteins that are targeted for secretion from the cell. for example, consider these two proteins: phosphofructokinase (pfk) is an enzyme that functions in the cytoplasm during glycolysis. insulin, a protein that regulates blood sugar levels, is secreted from specialized pancreatic cells. assume that you can track the cellular locations of these two proteins from the time that translation is complete until the proteins reach their final destinations.for each protein, identify its targeting pathway: the sequence of cellular locations in which the protein is found from when translation is complete until it reaches its final (functional) destination. (note that if an organelle is listed in a pathway, the location implied is inside the organelle, not in the membrane that surrounds the organelle.)

How do you date a sample of rock that you suspect as being one of the earliest on earth

Categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both. makes predictions