Why is the presence of an integral protein necessary for a charged particle, such as an ion, to cross a cell membrane?

Can bacteria reproduce in a way such that when you start out with two bacteria, you get five bacteria? why or why not? * a. yes, because bacteria reproduce sexually, and can produce any number of offspring, just as humans do. b. no, because bacteria grow at an exponential rate. c. no, because when bacteria reproduce, they split into two parts, and two bacteria splitting would result in four bacteria.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

2. which of the following statements does not accurately describe stem cells? a. embryonic stem cells make up the inner cell mass of a blastocyst. b. with more research, stem cells may be used to repair or replace damaged cells. c. the use of stem cells is without any objections since it can be used in therapies to humans. d. adult stem cells are multipotent and can differentiate into many types of cells.