How many nucleosomes are found in a helical coil of $30 \ nm$ chromatin fibre?

The double-helical structure of $DNA$ was proposed by:

Statement $P$: Uracil is not present in the structure of $DNA$.
Statement $Q$: $A-T$ complementary base pairing is present in the structure of $DNA$.

The two strands of $DNA$ are

Which scientist proposed the concept of the Central Dogma?

If the base sequence of one strand of $DNA$ is $GAT, TAG, CAT, GAC$,what would be the sequence of its complementary strand?