Match Column I with Column II

	Column I		Column II
a.	Methanogens	i.	Cell wall embedded with silica.
b.	Cyanobacteria	ii.	Present in the gut of several ruminant animals.
c.	Mycoplasma	iii.	Some organisms contain specialized thick walled cells called heterocysts.
d.	Diatoms	iv.	Organisms that completely lack a cell wall.

• A

  a- ii, b- iii, c-iv, d-i

• B

  a- iii, b- ii, c-iv, d-i

• C

  a- i, b- iii, c-iv, d-ii

• D

  a- ii, b- iv, c-iii, d-i