What is the cell nucleus?

Assume that a student is given two different models of bacteria, with one model consisting of big bacteria and the other consisting of small bacteria. how can the student demonstate the theory of endosymbiosis using the models

What was the land like over 500 million years ago? what was under the sea?

If t=tall and t=short what will be the physical appearance of the offspring the cross below? a. some will be tall and some will be short b. they will all be tall c. they will all be short d. they will be medium height