Which of the following accurately describes the structure of dna?
a. dna consists of four bases: a, g, c, and u.
b. dna is in the form of antiparallel strands twisted as a double helix.
c. a always pairs with c, and g always pairs with t.
d. dna is made up of nucleotides, containing a phosphate group, a base, and another phosphate group.

each of the 46 original chromosomes splits into two daughter chromosomes, so there are two sets of 46 daughter chromosomes that end up in each cell. human cells have 46 chromosomes. each chromosome consists of a pair of identical chromatids attached together by a structure called a centromere.

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion