Question

X-Rays cause mutations by

• A. Breaking spindle
• B. Rupturing of nuclear membrane
• C. Changing the chromosome morphology
• D. Inducing karyokinesis

Answer 1

The correct option is C Changing the chromosome morphology

X‐rays produce fragmentations of the chromosome commonly in the region of fiber attachment. Fiberless fragments become attached to other chromosomes or those portions of them that retain fiber attachments. Thus, chromosomes homologous to parts of two other chromosomes are produced and at synapsis multiples are formed. Such multiples are chains or closed‐circles depending upon whether a single or a reciprocal translocation respectively has occurred. Sometimes entire chromosomes unite to form a multiple. The locus of fiber attachment (acromite) is an integral part of a chromosome and its loss to one homologue causes non‐disjunction or other inequalities in the distribution of the chromatin.

So, the correct answer is 'Changing the chromosome morphology'.