Tumors secrete chemical signals that cause blood vessels from the circulatory system to grow into the tumor, providing nutrients. what is this called?
select one:
a. mitosis
b. mutation
c. apoptosis
d. angiogenesis
e. metastasis

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.