At what steps should arrows also be drawn in the opposite direction

When new rock is added to an oceanic ridge, the magnetized strips on either side of the ridge are evidence of sea-floor spreading. this is because the rocks on the two sides of the ridge o are equal in width and in polarity are polar opposites oare magnetized vary in width but are equal in polarity

What should be the strand of complementary dna produced by the strand of dna shown below cgt ata

Which topic is most likely to be studied by bo which topic is most likely to be studied by botanist? insect metamorphosis, viral infection, plant growth, animal physiology