The strongest plant cells are?

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

The polio virus can cause skeletal muscle paralysis by destroying neuron cell bodies. what area of the spinal cord is destroyed

Some plants release toxic chemicals that kill or harm nearby plants. what type of example is this? 1 cooperation 2.mutualism 3.competition or 4.parasitism