Explanation
- A
Chromosomes are composed of DNA and Protein.
Option (a) claims that chromosomes are composed of DNA and protein. This statement is scientifically true as eukaryotic chromosomes consist of DNA tightly wound around histone proteins.
- B
Nucleus of a cell does not play a role in cellular reproduction.
Option (b) claims that the nucleus of a cell does not play a role in cellular reproduction. This statement is factually incorrect because the nucleus contains genetic material and directs cell division and reproduction, making this the correct choice for the untrue statement.
- C
Chromosomes contain information for inheritance.
Option (c) claims that chromosomes contain information for inheritance of characters from parents to next generation. This statement is true as chromosomes bear DNA molecules which act as the hereditary units.
- D
Functional segment of DNA is called genes.
Option (d) claims that the functional segment of DNA is called genes. This statement is accurate since genes are specific nucleotide sequences on DNA that encode functional RNA or protein products.
Summary. Official key is (b) because the nucleus plays a vital and central role in cellular reproduction and division. Options (a), (c), and (d) state scientifically established facts regarding chromosomes, inheritance, and genes respectively. The nucleus houses the genetic blueprint, governs cellular activities, and replicates DNA during cell division. Therefore, claiming that the nucleus does not participate in cellular reproduction is completely false.