Question: Biosignature -32SH2- carbon-fixation- biomass- DNA polymerase -nitrogen-fixation -12CO2- RNA poly…

biosignature -32SH2- carbon-fixation- biomass- DNA polymerase
-nitrogen-fixation -12CO2- RNA polymerase -32SH2 -vertical gene
transfer- hopanoid -energy- horizontal gene transfer -13CO2-
isotope ratio (use these words to fill in the blank each one can
only be used once you will not need them all)

In order to identify when the first forms of bacterial life
began on earth, scientists use ____________________s that reflect
different forms of biological metabolism. For example, the
depletion of ____________________ from ancient mineralized carbon
rock represents the presence of ____________________ by bacteria
for the purpose of ____________________ production. Another
commonly used ____________________ is the presence of
____________________s that are specific to bacterial membranes.
Scientists use taxonomic trees to graphically show the evolutionary
relationship between bacterial species present on earth today.
Ideally, these trees represent the number of genome changes that
have accumulated over time due to ____________________ errors. For
this reason, scientist use the sequences of highly conserved genes
that are primarily inherited through ____________________.