UPSC Prelims 2019 question on Recent Science Developments

Statement by statement

Option (a) is NOT CORRECT: Functional chromosomes cannot be created by joining segments of DNA taken from cells of different species. Genes cannot be made from scratch by simply adding together the A's, T's, C's and G's — the 'bases' that make the rungs of the twisted DNA ladder.

Option (b) is CORRECT: DNA is an organic chemical molecule made from atoms of carbon, hydrogen, nitrogen, oxygen, and phosphorous. Like many other organic molecules that are made inside living cells, DNA can also be synthesized in test tubes using the tools of organic chemistry. Hence pieces of artificial functional DNA can be created in laboratories.

Option (c) is CORRECT: A piece of DNA taken out from an animal cell can be made to replicate outside a living cell in a laboratory.

Option (d) is CORRECT: Given appropriate surroundings, most plant and animal cells can live, multiply, and even express differentiated properties in a tissue-culture dish. Cells taken out from plants and animals can undergo cell division in laboratory petri dishes.