Question

Russian scientists made a fantastic discovery in Siberia. Thirty eight meters underneath the permafrost among bones of mammoth, bison, and wooly rhinoceros, they stumbled on a food stash of an Ice Age squirrel. The rodent buried seeds of a common Siberian plant Silent stenophylla for future consumption, future that, alas, was not meant to be. Radiocarbon dating confirmed that the seeds were 32,000 years old. Some of those ancient seeds were mature and damaged by the squirrel to prevent their germination, while immature seeds remained intact in the icy burrow. The scientists were able to extract plant cells from those immature seeds and remarkably were able to generate whole S, stenophylla plants that thrived and were able to flower and set seeds of their own, making them the oldest "resurrected" plants. The immature seeds _______. adapted from http //news.nationalgeographic.com/news 20l2/02/120221 - oldest - seeds - regenerated - plants - science/ are alive. are devoid of nucleic acids. were not metabolically active and therefore cannot be considered to be alive. have continued to evolve during all that time. are sensitive to low temperature.

Answer 1

Ans. If you recall cell theory by Theodor & Schwann, ‘all cells come from pre-existing cells (of course, alive cells)’.

Note the sentence ‘The scientists were able to extract plant cells from those immature seeds and remarkably were able to regenerate S. stenophylla’. To regenerate a whole plant from few cells of the host tissue (immature seed) through tissue culture techniques, the source cells must be alive- because only alive cells multiply and form a whole new plant through cell division and further differentiation.

Therefore, the immature seeds A. are alive.

Option B- incorrect. A cell devoid of DNA can’t not divide and form new cells. So, new plant can be generated from such cells by tissue culture.

Option C. Incorrect. Being metabolically inactive does not indicate that the specified entity is dead. For example, bacterial spores (and, immature seeds in this case) are metabolically inactive and can remain viable for several thousand years.

Option D. Incorrect. Evolution takes place only when the organism reproduce. Since the seeds were metabolically inactive, they can’t evolve during the period.

Option E. Incorrect. Seeds are sensitive to low temperature- the statement is true. However, this statement is NOT sufficient to explain the ‘regeneration of a whole new plant from preserved 32000 years old immature seeds.’ The only explanation is that the ‘immature seeds are alive’.