The three-spined stickleback is a species of fish. It lives in the ocean and in streams that flow into the ocean. Some scientists think that the ocean populations and stream populations may be
evolving into separate species.
Which of the following statements describes how speciation of these fish would most likely occur ?

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.