If ligase were absent, the most relevant consequence would be that new DNA strands would be made of disconnected pieces.
DNA ligase is an enzyme responsible for joining together the Okazaki fragments on the lagging strand during DNA replication, as well as sealing nicks in the DNA backbone that can occur during repair processes. Without ligase, these fragments wouldn't be properly connected, resulting in incomplete and fragmented DNA strands.
The other options you've provided are not accurate effects of ligase absence:
- "All of the nucleotides in the cell would magically disappear" does not logically follow from the absence of ligase.
- "DNA would be unable to unzip" is incorrect; the unzipping of DNA is primarily managed by helicase enzymes and is not dependent on ligase.
- "Base pairs would not be able to form" is not a direct consequence of ligase's absence; base pairing occurs during the synthesis phase but would be disrupted by the failure to join pieces.
- "RNA would be found mixed in with DNA strands" does not specifically relate to the absence of ligase.
In summary, the primary impact of not having DNA ligase is the inability to properly join fragmented DNA strands during replication and repair, leading to incomplete and non-functional DNA.