13. which of the following is not required by animals to control body temperature? a. animals must switch between ectotherm and endotherm methods. b. animals must be able to get rid of excess heat when temperatures increase. c. animals must be able to conserve heat when temperatures drop. d. animals must find a source of heat.

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.

Will give ! ! widentify the advantages and disadvantages of renewable and nonrenewable energy resources.

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? a) catalysis b) metabolism c) anabolism d) dehydration e) catabolism