Question

1. Mycoplasma pneumoniae lack cell walls. What sort of environment do they require for survival?

low temperature

hypertonic

isotonic

a biofilm

hypotonic

2. A cystic fibrosis patient with normal coloration of the mucus is infected with a bacteria able to metabolize a variety of organic chemicals. What is this nosocomial pathogen common among cystic fibrosis patients?

Haemophilus influenzae

Burkholderia

Pseudomonas aeruginosa

Klebsiella pneumoniae

Coxiella burnetii

3. Select all the of the statements below that apply to both eukaryotic and bacterial gene expression?

Bacteria and eukaryotes can have 70S ribosomes.

Bacteria and eukarytoes may have genes organized and regulated within operons.

Bacteria and eukaryotes have 70S ribosomes in their cytoplasm.

Initiation of translation in bacteria and eukaryotes occurs when the ribosomal subunit binds to the 5' guanine cap.

Bacterial and eukaryotic mRNA is modified prior to translation.

4. In which aspect below are archaea different than bacteria?

their cytoskeleton

their mechanism of cell division

their lack of membranous organelles

their ribosomal proteins   

5. Enterococcus faecalis bacteria can be distinguished from other Gram-positive cocci because enterococci

are highly sensitive to antibiotics.

have a glycocalyx.

produce catalase enzyme.

produce hemolysins.

can grow in the presence of bile salts.

Answer 1

1. Answer is: isotonic

The degree to which a particular cell is able to withstand changes in osmotic pressure is called tonicity. In hypertonic environments, cells that lack a cell wall can become dehydrated, causing shriveling of the cell; likewise, cells that lack a cell wall are more prone to lysis in hypotonic environments. So, cell that lack cell wall requires isotonic environment.

2. Answer is: Haemophilus influenzae

Hemophilus influenzae are the most common bacteria in cystic fibrosis.

4. Answer is: their ribosomal proteins

Both bacteria and archaea have different Ribosomal RNAs (rRNA). Archea have three RNA polymerases like eukaryotes, but bacteria have only one.

5. Answer is: can grow in presence of bile salts

The enterococci grow in presence of bile salts.