Greenhouse effect is the answer
He was holding a sedimentary rock
Robert Hooke is the first person to observe cells as microscopic structures.
He was of British descent and, fun fact, he discovered cells by looking at a sliver of cork under a microscope lens (although the 'fun fact' is heavily simplified).
The statement that a prion is an infectious, self-reproducing protein structure is true. Prion is short for <span>short for proteinaceous </span>infectious particle. <span>All known </span>prion<span> diseases in mammals affect the </span>structure<span> of the brain or other neural tissue. Hope this answers the question.</span>