Consider the following statements:

1. DNA replication takes place when chromatin is opened up.

2. Chromatin organizes itself into rod-shaped chromosomes before cell division.

3. Both prokaryotes and eukaryotes have the same process for cell division.

Which of the statements given above is/are correct?

The correct answer is  1 only.

Key Points

• DNA replication takes place when chromatin is opened up:
  • During the process of DNA replication, chromatin must be relaxed and opened up to allow the replication machinery to access the DNA strands.
  • This process ensures that the genetic material is accurately copied before cell division.
  • Chromatin remodeling is essential for replication, as it enables the replication forks to progress along the DNA.
  • Hence, statement 1 is correct.
• Chromatin organizes itself into rod-shaped chromosomes before cell division:
  • Chromatin condenses into visible chromosomes only during certain stages of the cell cycle, specifically during mitosis and meiosis.
  • In interphase, chromatin remains in a less condensed form to facilitate transcription and replication.
  • However, the statement implies that chromatin is always in rod-shaped chromosomes before any cell division, which is not accurate.
  • Hence, statement 2 is incorrect.
• Both prokaryotes and eukaryotes have the same process for cell division:
  • Prokaryotes and eukaryotes have fundamentally different mechanisms for cell division.
  • Prokaryotes undergo binary fission, a simpler process where the cell divides into two identical daughter cells.
  • Eukaryotes undergo a more complex process involving mitosis (for somatic cells) or meiosis (for gametes).
  • The processes involve different stages, regulatory mechanisms, and cellular machinery.
  • Hence, statement 3 is incorrect.

Additional Information

• DNA Replication:
  • DNA replication is a biological process that occurs in all living organisms and is the basis for biological inheritance.
  • It involves the unwinding of the double helix and the synthesis of new complementary strands by DNA polymerase.
  • Accurate replication is crucial for maintaining genetic integrity across generations.
• Chromatin Structure:
  • Chromatin is composed of DNA and histone proteins and is found in the nucleus of eukaryotic cells.
  • It exists in a less condensed form during interphase to allow for transcription and replication.
  • During cell division, chromatin condenses into chromosomes to ensure proper segregation of genetic material.
• Cell Division in Prokaryotes and Eukaryotes:
  • Prokaryotic cell division is relatively simple and involves binary fission, where the cell splits into two identical cells.
  • Eukaryotic cell division is more complex and can involve either mitosis or meiosis, depending on the type of cell and its function.
  • These processes ensure genetic material is accurately divided and distributed to daughter cells.