Which evidence originally supported Hess’s idea of seafloor spreading in 1968?
A) Younger rocks are closer to mid-ocean ridges.
B) The destruction of crust occurs at deep-sea trenches.
C) Oceanic rocks are pillow-shaped when formed.
D) Rocks across the ocean floor have alternating magnetic stripes.

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.