One of the biggest news stories of 1996 was the successful cloning of Dolly the sheep. Dolly was the first mammal cloned from an
adult body cell. At first, Dolly appeared to be perfectly healthy. However, she died at age 6 of cancer. Dolly’s early death made scientists wonder whether cloned animals age faster than normal. A small flock of sheep cloned from Dolly have been observed since 2007. Happily, these clones show no sign of early aging. Choose the best option to complete the sentence. Scientists worried that cloned animals would age rapidly because their cells contain __________________ as old as the individual they were cloned from.
Na is the elemental abbreviation for sodium, and Cl is the abbreviation for chlorine. When the two are combined, you get sodium-chloride, or table salt. Hope that helped =)
