What instrument was necessary before the cell theory could be developed?

What is the 77 element on the periodtic table

Is there any solid scientific evidence that humans have been cloned?

Which best describes this behavior? it is beneficial only to the males that do not fertilize eggs. it is beneficial only to the female workers that are not fertilized. it is beneficial to each one of the individual colony members. it is beneficial to the whole species, but not to all of the individual members.