Animal cells have a membrane that separates the interior of the cell from the outside environment. Typically, an electric potential difference exists between the inner and outer surfaces of the membrane. Consider one such cell where the magnitude of the potential difference is 66 mV, and the outer surface of the membrane is at a higher potential than the inner surface. A sodium ion (Na+) is initially just inside the cell membrane (initially at rest). How much work (in J) is required for a cell to eject the ion, so that it moves from the interior of the cell to the exterior?

Which of the following matches the organisms described with the correct domain? a. bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycanb. archaea--multicellular, eukaryotic organisms that do not have cell wallsc. eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sourcesd. bacteria--unicellular, eukaryotic organisms that always lack cell walls

Indicate whether the following statements about the biases in the fossil record are true or false. a) inland species are more likely to be preserved than marine species b) organisms with hard body parts are more likely to be preserved than are those composed soft tissues. c) species that existed over a larger area are more likely to be preserved than species existing over a smaller area. d) organisms that lived very long ago are more likely to be found as fossils than organisms that lived relatively recently e) the fossils of larger organisms are more likely to be found than the fossils of smaller organisms

Why does meiosis produce cells with half the chromosomes? o a. most of the chromosomes are not necessary to keep an organism alive. b. a gamete needs only half the number of chromosomes because two gametes join together. o c. it makes the gametes easier to move around in the organism. o d. it is faster to produce gametes with fewer chromosomes.