13. Which of the following are examples of complementary bases? A. cytosine and guanine
B. guanine and thymine
C. thymine and cytosine
D. cytosine and adenine

14. Guanine and cytosine are held together by what type of bonds?
A. ionic bonds
B. peptide bonds
C. covalent bonds
D. hydrogen bonds
DNA molecule is T-A-G-T-C-A. what is

2. which of the following statements does not accurately describe stem cells? a. embryonic stem cells make up the inner cell mass of a blastocyst. b. with more research, stem cells may be used to repair or replace damaged cells. c. the use of stem cells is without any objections since it can be used in therapies to humans. d. adult stem cells are multipotent and can differentiate into many types of cells.