An anaerobic step in cellular respiration, before the cell decides if it will go through fermentation or the Krebs Cycle and ETC

What did hunter gathers do to alter the environment?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Which scientific design has both practical limitations and limitations due to scale? studying the effect of bleach on the growth of mold spores exposing cultures of duckweed to different intensities of light observing the replication of dna molecules with a hand lens using colored marbles to model a cross between two colors of rabbits