When a cell divides, are the two resulting cells distinguishable in any reliable way?

That’s not how it works at all. The two daughter cells still retain the entire genome because the nucleotide sequence does not differ between them. Even though they inherit one parental strand and one newly synthesized strand each, their nucleotide sequences on both strand are exactly the same. How? When DNA is synthesized from the parental strand, it’s synthesized in an antiparallel fashion. so the newly synthesized strand is complementary to the other parental strand AND is exactly the same as the other parent strand because of complimentary base pairing. Take this for example...I think it’ll help

ACACAC = parental strand #1

TGTGTG= parental strand #2

  • remember parental strands are copied NOT made so when you hear that one daughter molecule contains one parental strand, it means it’s been copied and not like what you said.

*The other strand is made from those copied parental strands, but remember synthesis is achieved by complementary fashion (not copying mechanism). So if you have parent strand AG, the other synthesized strand would follow base pairing rules: so AG parent strand, is complementary to TC (not AG;that is copying).

DNA molecule (double stranded)

5’ ACACAC 3’ 3’ TGTGTG 5’

DNA REPLICATION RESULTS

Daughter molecule #I contains:

one newly made strand complementary (base pairs) with one of the parent strands. I’m sure you know the base pairing rules. One of the daughter cells is like so:

————Parent strand # 1: 5’ACACAC3’ Newlysynthesized strand: 3’TGTGTG5’

Daughter molecule II simply follows the same logic but this time you use parent strand #3 and DNA polymerase would synthesize it’s complement strand:

—-Parent strand 2: 3’TGTGTG 5’ Newlysynthesized: 5’ACACAC 3’

Now compare the two daughter molecules; they’re exactly the same as the parental DNA

I hope this made sense

/r/biology Thread