Question

The exchange of segments of non-sister chromatids between chromosome of a homologous pair is termed as
(a)Transformation
(b)Translocation
(c)Crossing over
(d)Chromosomal aberration

Answer 1

Hint: Many genetic variations occur during cell replication and division due to various agents that may be advantageous, neutral, or disadvantageous to the survival of the organism.

Complete answer:
The exchange of segments of non-sister chromatids between chromosomes of a homologous pair is termed as crossing over.

Additional Information:
Transformation: It is the genetic modification of a cell because of the direct uptake and merger of external genetic material from its surroundings through the cell wall. This principle is used in genetic engineering to insert desirable genes in the replicating cell.

Translocation: The chromosomal translocation is a phenomenon that leads to non-typical rearrangement of chromosomes. This comprises balanced and unbalanced translocation, with two main kinds: reciprocal translocation and Robertsonian translocation.

Crossing over: The exchange of chromosome segments between non-sister homologous chromatids that occurs during synapsis of meiosis is called crossing over.

Chromosomal aberration: A chromosomal aberration is a mutation in genetic material i.e. missing, extra, or irregular portion of chromosomal DNA. It can be from a usual number of chromosomes or a structural abnormality in one or more chromosomes.

So, the correct answer is “crossing over ”.

Note: During meiosis, the tight pairing of the homologous chromosomes is called synapsis. During synapsis, the genes on the chromatids of the homologous chromosomes are accurately aligned with each other, and crossing over takes place. The crossover events are the first cause of genetic variation created by meiosis. A crossover event in homologous non-sister chromatids results in an exchange of DNA between a maternal and a paternal chromosome. The recombinant chromatid features a combination of maternal and paternal genes that did not exist before the crossover.