Which is an example of chemical energy being transformed into heat energy? A. A bicycle moves forward when a person pedals it.
B. Plants convert energy from the Sun into food.
C. A campfire roasts a marshmallow that is held over the fire.
D. A falling rock heats up as it pushes against the air.

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.