Answer:
21 minutes or 0.35 hours
Explanation:
The formula for exponential population growth is
where
initial population of E.coli i.e 100
k is the rate of population growth i.e 2 as the population doubles
t is the time period i.e 20 minutes
Substituting the given values in above equation, we get -
Generation time
minutes
or 0.35 hours
Answer:
<u> The following images of different types of bacteria are attached here- </u>
<u>1- Single round bacterium- Cocci</u>
<u>2- Single rod-shaped bacterium- Bacilli</u>
<u>3- Cluster of round bacteria - Staphylococci</u>
<u>4- String of rod-shaped bacteria- Streptobacillus</u>
<u>5- Comma-shaped bacterium- Vibrio</u>
<u>6- Corkscrew-shaped bacterium- Spirillium</u>
Explanation:
<u>1- Single round bacterium- Cocci </u>-Any bacterium or archaeon that has a circular, ovoid, or usually round shape is a coccus (plural cocci). Cocci may develop in pairs, chains, or clusters during cell division, depending on their orientation and attachment. Many cocci bacteria do not have flagella and are non-motile, in contrast to many bacilli-shaped bacteria.
<u>2- Single rod-shaped bacterium- Bacilli </u>-A rod-shape bacterium or archaeon is a bacillus (plural bacilli), or bacilliform bacterium. In several different taxonomic classes, bacilli are found. Bacilli typically divide and are solitary in the same plane, but can combine to form diplobacilli, streptobacilli, and palisades.[2]
Diplobacilli: Two bacilli with each other arranged side by side.
Streptobacilli: Arranged bacilli in chains.
Coccobacillus: Coccus-like and oval (circular-shaped bacterium).
<u>3- Cluster of round bacteria - Staphylococci -</u> In the family Staphylococcaceae from the order Bacillales, Staphylococcus is a genus of Gram-positive bacteria. They appear spherical (cocci) under the microscope, and form into grape-like clusters. The species Staphylococcus are facultative anaerobic organisms (both aerobically and anaerobically capable of growth)
<u>4- String of rod-shaped bacteria- Streptobacillus -</u>Streptobacillus is a genus of fastidious gram-negative microaerophilic bacteria, an uncommon disease that develops in culture as rods in chains.t and can be caused by two forms of bacteria, Spirillum minus and Streptobacillus moniliformis.
<u>5- Comma-shaped bacterium- Vibrio </u>-Vibrio is a genus of Gram-negative bacteria with a curved-rod (comma) shape, which can cause foodborne infection in several animals, typically associated with consuming undercooked seafood. Vibrio species, usually found in salt water, are optional anaerobes that test positive for oxidase and do not form spores.
<u>6- Corkscrew-shaped bacterium- Spirillium </u>-Spirillum, a genus of spiral-shaped bacteria of the Spirillaceae family, aquatic with the exception of one species (S. minus) causing a form of human rat-bite fever. For any of the corkscrew-like animals, the name spirillum is used commonly.
Microbiologically, Spirillum is characterized as a gram-negative, motile helical cell with whiplike flagella tufts at each end.
<u>hence, the images of the different bacteria are attached below-:</u>
