Question

Select the incorrect statement.

• A. The cell envelope consists of a tightly bound three layered structure, of which plasma membrane is the innermost layer.
• B. A specialised differentiated form of cell membrane called mesosome is the characteristic of prokaryotes.
• C. Surface structures of the bacteria, like flagella, pili and fimbriae play a major role in motility.
• D. Gas vacuoles are found in blue green and purple and green photosynthetic bacteria.

Answer 1

Answer: (C)

Besides flagella, Pili and Fimbriae are also surface structures of the bacteria but do not play a role in motility. The pili are elongated tubular structures made of a special protein. The fimbriae are small bristle like fibres sprouting out of the cell. In some bacteria, they are known to help attach the bacteria to rocks in streams and also to the host tissues.