Consider the following differences between heterochromatin and euchromatin and choose the correct answer:
1. Heterochromatin stains deeply while euchromatin stains less deeply
2. Heterochromatin is late replicating while euchromatin replicates during the early stage of the S phase
3. Heterochromatin does not become acetylated but euchromatin takes up acetic acid on its histone during interphase
4. The crossover frequency is more in heterochromatin than in euchromatin