Question

Supernumerary chromosomes in plants and animals

• A. Are allosomes
• B. Are very small and genetically inert
• C. Mainly composed of heterochromatin
• D. Both B and C
• E. None of the above

Answer 1

The correct option is D Both B and C

Supernumerary chromosomes are also called as B chromosome. In addition to the normal karyotype, wild populations of many animal, plant, and fungi species contain B chromosomes (also known as supernumerary or accessory chromosomes). By definition, these chromosomes are not essential for the life of a species, and are lacking in some (usually most) of the individuals. Thus, a population would consist of individuals with 0, 1, 2, 3 (etc.) supernumeraries. They are small and inert in nature. These are composed of heterochromatin.