What is the endosymbiont hypothesis?

What is produced during the krebs cycle? co2, atp, nadh, and fadh2 pyruvate, co2, and atp atp, fadh2, and h2o h2o, adp, and nadh

When analyzing tree rings, what do scientists assume a thin ring indicates?

Which statement describes characteristics of planarians? a they live in oceans, are parasites, and reproduce only sexually. b they live in fresh water, are parasites, and reproduce only asexually. c they live in oceans, are free living, and reproduce sexually and asexually. d they live in fresh water, are free living, and reproduce sexually and asexually.