Question

Exchange of segments between non-homologous chromosomes is
A) Translocation
B) Inversion
C) Crossing over
D) Tetrasomy

Answer 1

Hint: The exchange of segments between chromosomes takes place during the cell division of reproductive cells called meiosis.It takes place in the reproductive cells.

Complete answer :
To answer this question we should know about the process of meiosis and how the exchange of non- homologous chromosomes takes place.
In Meiosis, the chromosomes divide into two. The homologous (similar) chromosomes exchange the segments or genetic information by the process known as crossing over. In this process the non sister chromatid pair which comes from each parent forms a pair so that the similar genes can cross over with each other. This results in the formation of new allelic combinations in daughter cells.

Sometimes certain variations occur. In some cases a segment of one chromosome gets exchanged with the segment of another non-homologous (dissimilar) chromosome. This results in the formation of a new linkage pair. This process is called Translocation.

At times a segment of Chromosomes gets reversed from end to end. This happens when a single chromosome breaks and then rearranges within itself. This process is called inversion.
In a few cases an abnormal number of chromosomes can be present in a cell. For example, a cell has two copies of a chromosome instead to two, it has four. Then this is called a tetrasomy.

Thus, the correct answer is (A). The exchange of segments of non-homologous chromosomes is called Translocation.

Note:In meiosis, the genes rearrange between the two chromosomes in each pair. The either one is received from each parent. It produces an altogether new chromosome with a unique genetic combination. At times variations can take place due to inversion, translocation, deletion or duplication. These variations can lead to abnormality. Chromosome translocation is seen in an abnormality called leukemia.