Where do the microtubules of the spindle originate during mitosis in both plant and animal cells ??

What is the difference between an igneous, sedimentary and metamorphic rock

In "the man in the water," what was the remarkable occurrence that rosenblatt reported?

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).