How might zircons scientists study early earth?
zircons are the remains of billions and billions of cyanobacteria.
zircons may add more radioactive isotopes to radiometric dating techniques.
zircons show how the earth's crust formed.
zircons may hold evidence of early life and atmospheric composition.

The Earth crust formation show by Zircon helps scientists to study early Earth.

Option C

Zircon is a popular mineral which is formed of mainly zirconium sulphate crystals and are mainly blue in colour. Zirconium sulphate crystals are very old in nature, dating back to thousands of years. These minerals actually hold the chemicals that were formed back then.

This minerals can be studied to explain how were the landforms and chemical composition of earth crust back to thousands of years. Zircons can also hold some other radioactive elements which were radioactive back to thousands of years, but now they are normal.

"do a testcross with a homozygous recessive plant."