Microorganisms are involved in which procces?
deomposition of organic material, infection, o2 production, food production.
Commercial utilization of microbial products has become increasingly popular due to their environmentally friendly nature. Removal of these products from the environment typically utilizes
If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?
using a sterile liquid and elimanting exposure to microorganism
Regarding Louis Pasteur's experiments with the S-neck flask, which of the following statements is TRUE?
air exchange involved food source was provided, possibility of the cantamination was removed all prexisting microorganism were killed
A scientist wants to perform a test that will indicate whether a nucleic acid sample is composed of RNA or DNA. Testing for the presence of which of the following is most appropriate in this situation?
Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 35S. After a 48-hour incubation, the 35S would most likely be found in the S. cerevisiae's
Two glucose molecules are combined to make a maltose molecule. What is the chemical formula for maltose?
C12 H2 22 O11
What structure does light pass through after leaving the condenser in a compound light microscope?
Which of the following places the steps of the Gram stain in the correct order?1-Alcohol-acetone
Which of the following places the steps in the correct sequence?
2-Making a smear
2 3 1
Which of the following correctly traces the path of light through the compound microscope?
light source; condenser; specimen; objective lens; ocular lens
You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the first dye. What is the appearance of the bacteria at this point?
You are performing a Gram stain on gram-negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point?
You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point?
Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are
Which of the following statements is INCORRECT regarding prokaryotic cells?
They lack a plasma membrane
Each of the following statements concerning the gram-positive cell wall is true EXCEPT
protects the cell in a hypertonic enviorment
Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5 percent NaCl?
water will move out
A gram-positive bacteria suddenly acquires resistance to the antibiotic methicillin. This trait most likely occurred due to
By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration?
Which of the following is NOT a typical characteristic of most bacterial plasma membranes?
Which of the following pairs is mismatched?
A) endoplasmic reticulum internal transport
B) Golgi complex secretion
C) mitochondria ATP production
D) centrosome food storage
E) lysosome digestive enzymes
centrosomes and food storage
Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of
Which of the following statements about gram-negative cell walls is FALSE?
they are sensitive to penicilin
Which structure acts like an "invisibility cloak" and protects bacteria from being phagocytized?
Which diagram of a cell wall possesses molecules responsible for symptoms associated with infection?
Which diagram of a cell wall has a structure that protects against osmotic lysis?
both gram positive and gram negative protect against osmotic lysis
Which of the following statements is correct about diffusion?
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of radioactivity will be found in the cells'
DNA and proteins
A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained
Which of the following is the best definition of generation time?
the length of time needed for a cell to divide