What cells are the stem cells for spermatogenesis?

How does buring fossil fuels impact does carbon cycle? what large impact does this have on the envirnment?

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.

Which of the following describes the difference in stimuli required to detect a difference between the stimuli? a. just noticeableb. signal detectionc. subliminald. top down