what's our system of naming organisms called, and what are the two most specific categories of organization?

The transport tubes for food coming down the plants are called?

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

To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a