During prophase 1 of meiosis, crossing over between the sister chromatids occurs. what is the purpose of the process? A. to produce genetic variaton
B. to duplicate the dna
C. to produce the spindle fibers
D. to remove the nuclear envelope

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c.carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit