Med Micro Chapter 4

Which of the following statements about cell walls is false? A. All bacterial cell walls contain teichoic acids. B. Plants and fungi have cell walls. C. Bacteria which have lost their cell wall are known as L-forms D. Algal protists have cell walls.

a

Which of the following statements about the prokaryotic cells surface-to-volume ratio is false? A. Because of their small size, bacteria have a small surface-to-volume ratio. B. Eukaryotes have surface-to-volume ratio that is only 1/10 that of prokaryotes. C. The prokaryotes surface-to-volume ratio means that nutrients can easily and quickly reach all parts of the cell as no internal part of the cell is very far from the surface. D. A bacteria with a surface area of about 12 microns squared and a volume of 4 cubic microns has a surface-to-volume ratio of 3:1.

a

______________ occurs when bacteria differ widely in form. A. Pleomorphism B. Polymorphism C. Anamorphism D. Telomorphism

a

Bacteria move by means of: A. cilia B. flagella C. fimbriae D. pili

b

Endospores are typically found in the genus: A. Streptococcus B. Clostridium C. Mycobacterium D. Staphylococci

b

Peptidoglycan makes up more than 50% of a ________ cell wall. A. Gram negative B. Gram positive C. Gram variable D. acid-fast

b

Prokaryotic cells divide by ______________ A. mitosis B. binary fission C. meiosis D. mitosis asexually and meiosis sexually

b

The _____ portion of the cell membrane functions as a barrier while the ______ portion provides specific functions, including pumps, receptors, adhesion, etc. A. carbohydrate; nucleic acid B. lipid; protein C. lipid; carbohydrate D. nucleic acid; lipid

b

The charged, phosphate end of a membrane phospholipid is: A. water-fearing B. hydrophilic C. hydrophobic D. none of these

b

The shape of a bacterial cell is determined (and maintained) by the _____. A. cell membrane B. cell wall C. capsule D. slime layer

b

Which of the following cellular structures are found only in prokaryotic cells? A. endoplasmic reticulum B. pili C. nucleolus D. lysosomes

b

Mitochondria: A. are responsible for converting sunlight to chemical energy B. are present only in photosynthetic organisms C. have a double membrane D. are responsible for protein synthesis

c

The outer (cell) membrane component of the cell wall _____. A. is found only in Gram positive bacteria B. is made primarily of peptidoglycan C. contains lipopolysaccharrides D. is primarily a reproductive structure

c

The rough endoplasmic reticulum appears rough because of _____. A. sterols in its membrane B. fats and sugars on its surface C. multiple ribosomes on its surface D. proteins in the lumen of the ER

c

Which bacterial genus normally lacks a cell wall? A. Mycobacterium B. Streptococcus C. Mycoplasma D. Bacillus

c

Which of the following is not a common bacterial shape? A. Spirochete B. Coccus C. Disc D. Bacillus

c

Which of the following statements about the endosymbiotic hypothesis is false? A. Eukaryotic cells have both 70S and 80S ribosomes. B. Mitochondria have their own DNA. C. When removed from cells, mitochondria continue to grow and divide. D. Mitochondria are about the same size as prokaryotic cells.

c

A charged molecule which moves down its concentration gradient and across a pore in a cell membrane without energy being expended by the cell is experiencing _____. A. simple diffusion B. osmosis C. active transport D. facilitated diffusion

d

Eukaryotic cells add rigidity to their plasma membrane by including what component in the membrane? A. Protein B. Lipids C. Sugars D. Sterols

d

Genetic information in bacteria is: A. found in the nucleus B. found only in RNA C. found in DNA condensed by histones D. sometimes found in the form of plasmids

d

Penicillin controls the growth of bacteria by _____. A. destroying cell membranes B. preventing protein synthesis C. removing cell walls D. preventing peptidoglycan synthesis

d

The periplasmic space is found _____. A. only in Gram positive organisms B. between the nuclear area and the cell membrane C. primarily in acid fast bacteria D. between the innercell membrane and outer cell wall membrane

d

When the fluid within a cell has a higher concentration of dissolved substances than the fluid surrounding the cell, we say the fluid surrounding the cell is _____. A. hypertonic B. isotonic C. superhypertonic D. hypotonic

d

Which of the following cellular structures can be found in both prokaryotic and eukaryotic cells? A. Golgi apparatus B. lysosomes C. peroxisomes D. ribosomes

d

Which of the following structures is not normally part of a bacterial flagellum? A. Hook B. Filament C. Basal body D. Anchor

d