Certain kinds of shells are always found in rock layers lower than layers with plant fossils. Dinosaur fossils show up only in layers above or with plant fossils what does this tell you about When these organisms lived

What did the first language sound like

Acquired mutations can result from radiation pollution toxins inheritence select all that apply

Which of the following are not matched correctly? cd8+: directly destroy infected or cancerous cells t reg cell: reduce the adaptive response once threat passes t l: activate cellular branch (cytotoxic t cells, macrophages, nk cells) t 2: stimulate b cells to make antibodies t (cd4+): mhc i