$A$ repeated cycle of $DNA$ replication without separation of daughter chromatids leads to the formation of

The beaded appearance of chromosomes is known as

Which structure appears like 'beads-on-string'?

Chromatin found in the nucleus was discovered by

The shape of the chromosome is determined by

Identify the cell organelle based on the following characteristics:
- It is not a membrane-bound organelle.
- It is the site for active ribosomal $RNA$ $(rRNA)$ synthesis.
- It is a spherical structure.