What cells are the stem cells for spermatogenesis?

The population of bacteria in a petri dish doubles every 40 seconds. the population of the bacteria is initially 400 organisms. what unit is most appropriate for the time at which the number of bacteria is 300? hour bacteria per hour second bacteria per second

Study the image of this rock.which characteristic best supports its formation from sedimentary processes? it has many layers.it is coarse-grained.its grain shape is round.its texture is non-banded.

Which part of cellular respiration must occur before any of the other steps can occur