Which of the following is a possible nucleotide found in dna?
ribose sugar + phosphate group + adenine
ribose sugar + phosphate group + uracil
deoxyribose sugar + phosphate group + thymine
deoxyribose sugar + phosphate group + uracil

Which of the following is a main difference in cell structure between an onion cell and a human cheek cell? a. an onion cell contains one nucleus, whereas a human cheek cell contains two nuclei. b. an onion cell has a cell wall. c. a human cheek cell contains chloroplasts. d. there is no difference between an onion cell and a human cheek cell. you for your.

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics?