Growth Phases of Organisms

Caesin hydrolysate is useful in identifying organisms that can cause hemolysis, or breakdown of red blood cells.

Blood agar is a medium that encourages growth of some organisms but suppresses the growth of others.

A selective medium is a medium that has a constituent that causes an observable change in the medium when a particular biochemical reaction occurs.

<p>A differential medium is a medium that has a constituent that causes an observable change in the medium when a particular biochemical reaction occurs.</p> Signup and view all the answers

<p>SPS and MacConkey agar are selective and differential mediums.</p> Signup and view all the answers

<p>Lactose is a sugar that organisms in the human intestines ferment, whereas most pathogens do not.</p> Signup and view all the answers

<p>The pour plate method is a technique where a diluted culture is added to a melted nutrient agar and poured into an empty dish, allowing bacteria to grow on top of the agar.</p> Signup and view all the answers

<p>The spread plate method is a technique where a diluted sample is placed on the center of a solid cooled agar medium and spread evenly, allowing colonies to develop on the agar surface.</p> Signup and view all the answers

<p>A colony forming unit (CFU) is a single living bacterium that is deposited on an agar plate and divides to form a colony.</p> Signup and view all the answers

<p>The most probable number (MPN) method is a method of estimating the size of small bacterial populations when samples contain too few organisms to give reliable measures of population size by the standard plate count method.</p> Signup and view all the answers

<p>During the lag phase, organisms increase in size, synthesize enzymes, and incorporate various molecules from the medium.</p> Signup and view all the answers

<p>Population growth occurs at an exponential rate during the log phase.</p> Signup and view all the answers

<p>During the stationary phase, conditions in the medium become less supportive of cell division, cells lose their ability to divide, and cells die.</p> Signup and view all the answers

<p>During the decline phase, cell division decreases to the point that new cells are produced at the same rate as old cells die, so the number of cells remains constant.</p> Signup and view all the answers

<p>The generation time is the time it takes for organisms to divide at their most rapid rate.</p> Signup and view all the answers

<p>Synchronous growth refers to cells dividing sometime during the generation time with a smooth line graph rather than a stair step pattern.</p> Signup and view all the answers

<p>Nonsynchronous growth refers to cells dividing together exactly and increasing in a stair step pattern.</p> Signup and view all the answers

<p>A colony is a group of descendants of the original cell.</p> Signup and view all the answers

<p>The streak plate method is a method that uses agar plates and involves picking up bacteria on a sterile wire loop and depositing streaks of bacteria along the surface.</p> Signup and view all the answers

<p>Natural media are materials found in nature, while synthetic media are materials from the laboratory.</p> Signup and view all the answers

<p>Lag phase</p> Signup and view all the answers

<p>Log phase</p> Signup and view all the answers

<p>Stationary phase</p> Signup and view all the answers

<p>Decline phase</p> Signup and view all the answers

<p>Generation time</p> Signup and view all the answers

<p>Synchronous growth</p> Signup and view all the answers

<p>Nonsynchronous growth</p> Signup and view all the answers

<p>Colony</p> Signup and view all the answers

<p>Complex media</p> Signup and view all the answers

<p>Defined synthetic media</p> Signup and view all the answers

<p>Blood agar</p> Signup and view all the answers

<p>To identify organisms that can cause hemolysis</p> Signup and view all the answers

<p>Estimating the size of small bacterial populations</p> Signup and view all the answers

<p>To ferment by organisms in the human intestines</p> Signup and view all the answers

<p>Organisms in the human intestines</p> Signup and view all the answers

<p>Spreading a diluted sample evenly on a solid cooled agar medium</p> Signup and view all the answers

<p>Measuring bacterial growth indirectly</p> Signup and view all the answers

<p>A colony known as a single living bacterium deposited on an agar plate</p> Signup and view all the answers

<p>To measure the direct or indirect uptake of oxygen</p> Signup and view all the answers

<p>To turn blue in the presence of oxygen and colorless in its absence</p> Signup and view all the answers