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

Could someone me with number one you

How are the reproductive cycles of a fungus and a pteridophyte similar? a)both organisms form fruiting bodies that produce diploid seeds. b)both organisms produce haploid spores and exhibit diploid and haploid stages. c)both organisms reproduce sexually when two haploid hyphae fuse. d)both organisms exhibit a diploid stage and are only able to reproduce asexually.

Match the pollutants. 1. a chlorofluorocarbon smoke 2. a biodegradable organophosphate insecticide freon 3. particle pollution paint 4. hazardous waste monoxide 5. carbon is completely burned malathion 6. carbon is incompletely burned dioxide