When bacterial cell walls are covered with an outer membrane that contains lipopolysaccharide, they are
a. gram-negative
b. gram-positive
c. encapsulated
d. saturated

a. Gram negative

Explanation:

Lipopolysacchirides are found in the outer membrane of gram negative bacterial cell wall exposed to surface and are endotoxins that protects them from harmful chemicals. They are composed of lipids and polysaccharides. Gram negative bacteria are pathogenic due to their cell wall.

d. groundwater flows through the subsoil and deposits minerals.