Geologists use - to determine a rock layer's absolute age

Which of these is not a nucleotide base found in dna?

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a. an ionic bond is formed between the oxygen and carbon atoms. b. four valence electrons are shared. c. two valence electrons are shared. d. valence electrons are shared between oxygen atoms.

Which feature would you expect to find in a population in which sexual selection depends on male competition?