Correct Option (a)
The statement is incorrect. While recombinant DNA technology allows for the joining of DNA segments from different species, the creation of a fully functional chromosome assembled entirely from such interspecies DNA is not currently achievable. Functional chromosomes are highly complex structures requiring precise organization, specific regulatory sequences, and epigenetic modifications to operate correctly within a living cell. Current genetic engineering capabilities primarily involve manipulating individual genes or synthesizing smaller, defined DNA constructs, rather than constructing complete, functional chromosomes from diverse species' genetic material.
Incorrect Options:
The following statements are correct:
Option (b): Pieces of artificial functional DNA can be created in laboratories.
This statement is correct. Scientists routinely synthesize artificial DNA segments, including genes and regulatory regions, using automated DNA synthesizers. This capability is fundamental to genetic engineering and synthetic biology, exemplified by projects involving the creation of synthetic bacterial genomes.
Option (c): A piece of DNA taken out from an animal cell can be made to replicate outside a living cell in a laboratory.
This statement is correct. DNA replication outside a living cell is a standard laboratory procedure, most commonly achieved through the Polymerase Chain Reaction (PCR). PCR utilizes enzymes such as Taq polymerase to amplify specific DNA sequences without the need for an intact living organism.
Option (d): Cells taken out from plants and animals can be made to undergo cell division in laboratory petri dishes.
This statement is correct. Both plant and animal cells can be successfully cultured in vitro and induced to divide in laboratory petri dishes. This requires providing appropriate growth media, nutrients, and controlled environmental conditions. Examples include plant tissue culture techniques like callus culture and the establishment of various animal cell lines for research.