Question

Beads on string like structures of A are seen in B, which further condense to form chromosomes in C stage of cell division.

	A	B	C
(a)	Chromonema	Chromatin	Metaphase
(b)	Chromatin	Chromatid	Metaphase
(c)	Chromonema	Chromosome	Anaphase
(d)	Chromonema	Chromatid	Anaphase

Answer 1

The correct option is:

	A	B	C
(a)	Chromonema	Chromatin	Metaphase

Explanation:

The "beads-on-a-string" structure is seen in electron microscope of isolated metaphase chromosomes. The chromonema form the gene bearing portions of the chromosome, Basically chromonema is made up of nucleosome chains. Nucleosome chain gives a beads on string appearance under electron microscope. Nucleosome Is the fundamental packaging unit in eukaryotic chromosomes.