Which of the following is a purine base in DNA? O A. Adenine
B. Pyrimidine
O C. Cytosine
O D. Thymine

How are mutations continually being generated in a population (what are some of the causes of mutatuions? ) explain

What is responsible for the uneven heating between the poles and the equator on any given day

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.