Answer:
1.Janssen's microscope consists of three draw tubes with lenses inserted into the ends of the flanking tubes. The eyepiece lens was bi-convex and the objective lens was plano-convex, a very advanced compound design for this time period.
2.Hooke had discovered plant cells -- more precisely, what Hooke saw were the cell walls in cork tissue. In fact, it was Hooke who coined the term "cells": the boxlike cells of cork reminded him of the cells of a monaster
3.Compound microscopes (that is, microscopes using more than one lens) had been invented around 1595, nearly forty years ...
4. 1882, the German physician Robert Koch presented his discovery of Mycobacterium tuberculosis, the bacilli responsible for tuberculosis. ... But in 1931, German scientists Ernst Ruska and Max Knoll overcame this theoretical barrier with the electron microscope.
Explanation:
A microscope is an instrument that is used to magnify small objects. ... It is through the microscope's lenses that the image of an object can be magnified and observed in detail. A simple light microscope manipulates how light enters the eye using a convex lens, where both sides of the lens are curved outwards
