Question

Secondary constriction II of chromosome is generally concerned with the

• A. Synthesis of rRNA
• B. Synthesis of tRNA
• C. Synthesis of mRNA
• D. All of the above

Answer 1

The correct option is A Synthesis of rRNA

Secondary constriction II of chromosome is generally concerned with the synthesis of rRNA. Secondary constriction is seen at the chromosome in addition to primary constriction or centromere. Chromosome can bend only at the site of primary constriction during anaphase. 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. Some parts of these constrictions indicates sites of nucleolus formation and so they are called Nucleolar Organizing Region. The formations of nucleolus takes place around the NOR region. The secondary constriction also contains the genes for rRNA synthesis.