Question

In human being, secondary constrictions II are found on

• A. X chromosome
• B. Y chromosome
• C. 13, 14, 15, 21, 22 chromosome
• D. 1, 10, 13, 16 and Y chromosome

Answer 1

Answer: (C)

13, 14, 15, 21, 22 chromosome

Secondary construction is the nucleolar organizer region which involves in the nucleolus formation. It occurs in the 13, 14, 15, 21, 22 chromosomes. It contains the genes for rRNA synthesis. Secondary constrictions are useful in identifying a chromosome from a set. There are either 0, 1, 2, 3, or 4 secondary constriction sites in a cell at anaphase.