New nucleotides are attached to the parental strand of dna in an area called the
double helix.
nucleus.
replication bubble.
none of the above

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

dna is a set of a gene held together by a chemical bond