This is the normal nucleotide sequence on a dna strand:
a—c—t—g—g—a—t
what is a substitution?

select one:
a.
a—c—t—g—c—g—a—t

b. a—c—t—g—a—t
c. a—g—t—g—g—a—t
d. a—c—u—g—g—a—u

Which statement correctly describes other ways in which nebulae and stars are different? a. a star always has a higher density than a nebula. b. stars can form inside a nebula but a nebula can never be produced by any star. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star. reset submit