1. Why would a bacterial culture not continue to double after a while?
a. The culture needs more light.
b. The culture only reproduces for 5 generations.
c. The culture has switched to a different type of reproduction.
d. The culture needs more enzymes to continue.
e. The culture can only double for a given number of generations until the nutrients are depleted and wastes are produced. ***
2. Once biofilms become sessile, they are which of the following?
a. Not able to divide
b. Attached ***
c. Motile
d. Easily washed off
e. Washed off
3. Which of the following would indicate the most significant number of bacteria in a solution?
a. 0% of the light would pass through.
b. 10% of the light would pass through.
c. 50% of the light would pass through.
d. All light would pass through. ***
e. 20% of the light would pass through.
4. Which of the following needs to occur before a cell can divide?
a. DNA replication ***
b. Cytokinesis
c. Formation of a septum
d. Formation of Z ring
e. Formation of cleavage furrow
5. Which bacterial species needs oxygen?
a. Obligate anaerobe
b. Obligate aerobe ***
c. Microaerophile
d. Aerotolerant anaerobe
e. Facultative anaerobe
6. Given a colony of bacteria is growing in optimal conditions, which of the following would have the largest population in 24 hours?
a. Either Mycobacterium leprae or Mycobacterium tuberculosis
b. Either Escherichia coli or Mycobacterium tuberculosis
c. Escherichia coli ***
d. Mycobacterium leprae
e. Mycobacterium tuberculosis
7. Prokaryotic cells replicate by which of the following?
a. Schizogony
b. Mitosis
c. Meiosis
d. Binary fission ***
c. Conjugation
1. e. The culture can only double for a given number of generations until the nutrients are depleted and wastes are produced. Just like that friend who promises to keep buying you ice cream but eventually runs out of money and ice cream shop discounts.
2. b. Attached. Once biofilms become sessile, they stick to surfaces like your ex clingy partner who just can't let go.
3. d. All light would pass through. Imagine the bacteria throwing a rave party and no one shows up, that would be a significant indication of a low bacterial count.
4. a. DNA replication is a must before a cell can divide, just like reading the user manual before assembling IKEA furniture, otherwise, you'll end up with a lopsided bookshelf.
5. b. Obligate aerobe. These bacteria need oxygen to survive, just like those people who can't go 5 minutes without posting a selfie on social media.
6. c. Escherichia coli. These guys are fast reproducers, like those rabbits that somehow manage to multiply like crazy no matter how many times you try to chase them away from your garden.
7. d. Binary fission. Prokaryotic cells perform binary fission, which is like a single-cell version of "The Parent Trap", where one cell splits into two identical cells.
1. The correct answer is e. The culture can only double for a given number of generations until the nutrients are depleted and wastes are produced.
2. The correct answer is b. Attached.
3. The correct answer is d. All light would pass through.
4. The correct answer is a. DNA replication.
5. The correct answer is b. Obligate aerobe.
6. The correct answer is c. Escherichia coli.
7. The correct answer is d. Binary fission.
1. The correct answer is e. The culture can only double for a given number of generations until the nutrients are depleted and wastes are produced. Bacterial cultures go through a process called binary fission, where one parent cell divides into two identical daughter cells. However, this process can only continue until the available nutrients are consumed and waste products build up, which eventually leads to the culture's growth slowing down or coming to a stop.
2. The correct answer is b. Attached. Once biofilms become sessile, they attach to a surface and become firmly established. Biofilms are communities of microorganisms that can form on various surfaces, and once they attach, they become more resistant to removal and less mobile.
3. The correct answer is d. All light would pass through. This indicates that there are no bacteria present in the solution. When light passes through a solution without any bacteria, it is not scattered or absorbed by microbial cells, resulting in 100% transmission.
4. The correct answer is a. DNA replication. Before a cell can divide through binary fission, its genetic material (DNA) needs to be replicated. This ensures that each daughter cell receives a complete set of genetic information.
5. The correct answer is b. Obligate aerobe. This type of bacteria requires oxygen to carry out their metabolic processes. They cannot survive and grow without oxygen.
6. The correct answer is c. Escherichia coli. Among the given options, Escherichia coli (E. coli) is known to have a shorter generation time and faster growth rate compared to other bacteria such as Mycobacterium leprae or Mycobacterium tuberculosis. Therefore, E. coli would have the largest population in 24 hours under optimal conditions.
7. The correct answer is d. Binary fission. Prokaryotic cells, including bacteria, replicate through binary fission. In this process, the single circular chromosome of the bacterium is duplicated, and the two copies move to opposite ends of the cell. The cell then elongates and divides into two daughter cells, each containing one copy of the replicated chromosome. This results in the formation of two genetically identical daughter cells.