Why mammal embroys and dinosaur embroys have placodes

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

Most crimes involve some evidence relating to the human body; for that reason, what related science is frequently used in forensic investigations? a)psychiatry b)physics c)botany d)biology

Error analysis: what might be the reason that some of your percentages didn't exactly match your predicted results? gametes aren't responsible for inheritance. mice don't have large litters, so the sample size was not large enough. the wrong type of mice were used.