Final answer:
Bacillus anthracis appears as gull-wing-shaped rods under a microscope, distinguishing it from Yersinia pestis with its safety pin appearance and Streptococcus pneumoniae with its lancet-shaped cells.
Step-by-step explanation:
The organism that resembles Gull-Wings under the microscope is Bacillus anthracis. This bacterium is well-known for causing anthrax. When observed under a microscope, Bacillus anthracis appears as large, blocky rods in chains, which can resemble gull wings. None of the other options listed, Yersinia pestis (which causes plague and presents a "safety pin" appearance), Klebsiella pneumoniae, or Streptococcus pneumoniae (characterized by its lancet-shaped diplococcal morphology), show a gull-wing morphology.
While Yersinia pestis does not exhibit the gull-wing appearance, it is notable for its "safety pin" appearance in stained samples, a characteristic that aids in the diagnosis of plague. Streptococcus pneumoniae, with its lancet-shaped cells, is known to cause types of pneumonia but is not characterized by gull-wing morphology.