Microbial Genetics and Genomics Quiz

Reproduction involving two organisms combining their DNA to create offspring with diverse traits.

Reproduction where one organism creates an identical copy of itself, resulting in offspring with the same traits.

Transfer of genetic material between unrelated or distantly related organisms, not through reproduction.

Bacteria takes up free, naked DNA from the environment and incorporates it into its own genome.

Genes are transferred between bacteria via a virus.

Transfer of genetic material between bacteria through direct contact.

A specific piece of bacterial DNA is transferred from one infected cell to another by a phage.

Transfer of genes between bacteria through direct cell-cell contact using a sex pilus.

Bacterial strains where the F plasmid is integrated into the host chromosome.

A phage infects a bacterial cell; fragments of bacterial DNA are packaged into phage particles, and the resulting phages can transfer this DNA to another bacterium.

An imbalance in the normal gut microbiota, possibly leading to disease.

The complete set of genes found in all strains of a species.

A cluster of genes in a bacterial chromosome that likely came from another organism and is often associated with specialized functions.

A defense mechanism in the respiratory system where cilia on the lining of the trachea move mucus, trapping foreign particles and sweeping them out of the lungs.

Alveoli, the tiny air sacs in the lungs, have specialized defenses like surfactant (an antimicrobial), mucus secretions, alveolar macrophages, and dendritic cells to protect against infections.

The urogenital tract has different microbial habitats, with the vagina being acidic due to lactic acid produced by resident bacteria, maintaining a protective environment.

The skin microbiome is influenced by diverse environmental factors such as moisture, acidity, and oil production, resulting in different microbial communities on different areas.

The gut microbiome is dominated by anaerobic bacteria, with Firmicutes, Bacteroidetes, and Proteobacteria being the major groups. They play crucial roles in digestion, immunity, and overall health.

Commensal bacteria in the gut have a mutually beneficial relationship with the host. They aid in digestion, produce beneficial compounds like short-chain fatty acids, and contribute to immune system development.

While gut microbiota normally protects against disease, disruption of its balance can lead to opportunistic pathogens causing infection. Factors like diet, antibiotics, and stress can affect this balance.

The composition of the gut microbiota varies greatly from person to person and can change over time due to factors like diet, age, and physiology, influencing immune function and overall health.

Gut microbiota plays a crucial role in energy production, breaking down carbohydrates that humans cannot digest, providing an additional energy source for the host.

Babies born vaginally have a microbiome similar to their mother's, while C-section babies have a different microbiome.

Breastfed babies have a different gut microbiome than formula-fed babies due to the presence of complex sugars in breast milk. This promotes diverse bacteria.

As we age, our gut microbiome becomes less diverse and has more Bacteroides bacteria.

A high-fiber diet with diverse fiber types strengthens the gut microbiota by providing food for beneficial bacteria. This helps to outcompete harmful bacteria.

Dysbiosis is an imbalance of gut bacteria, often caused by factors like antibiotics, poor diet, and stress.

A high-fat diet can lead to inflammation in the gut because it increases the absorption of endotoxins, which trigger inflammatory reactions.

Gut inflammation can occur when there's a break in the gut barrier, an increase in harmful bacteria, or a disruption in the immune system.

Our gut microbiota helps us get energy by breaking down sugars into short-chain fatty acids (SCFAs).

Changes in the types and amounts of gut bacteria, including methanogenic Archaea, can influence obesity.

Using mice to study the gut microbiota has limitations, as not all human gut bacteria can colonize mice, and mouse gut anatomy is different.

Glycoproteins or lipoproteins on a bacterial cell wall that bind to receptors on host cells, allowing bacteria to attach.

A polysaccharide coat surrounding bacteria that protects them from phagocytosis by hiding them from immune cells.

An enzyme produced by some bacteria that breaks down hyaluronic acid, a substance that holds cells together, allowing bacteria to invade deeper tissues.

An enzyme produced by bacteria that forms a blood clot around itself, shielding it from immune cells and providing a source of nutrients.

A syringe-like structure used by bacteria to inject proteins directly into host cells, manipulating the host cell for the bacteria's advantage.

Proteins injected by bacteria into host cells through the Type III secretion system, they manipulate host cell functions for bacterial benefit.

A system used by bacteria to secrete proteins outside the cell, similar to the Type IV pilus, often for spreading toxins or enzymes.

A system used by bacteria to secrete proteins and sometimes DNA directly from the cytoplasm or periplasm into host cells.

Passing genetic information from parent to offspring during reproduction. Think of it like a direct line of inheritance.

Transfer of genetic material between organisms not directly related through reproduction, like sharing genetic snippets.

Genes are transferred between bacteria through a virus (phage) acting as a genetic courier.

As we age, our gut microbiome loses diversity and has more Bacteroides bacteria.

The tiny air sacs in the lungs (alveoli) have specialized defenses like surfactant (an antimicrobial), mucus secretions, alveolar macrophages, and dendritic cells to protect against infections.

The urogenital tract has different microbial habitats, with the vagina being acidic due to lactic acid produced by resident bacteria, maintaining a protective environment. This acidity prevents the growth of many harmful bacteria.

The skin microbiome is influenced by diverse environmental factors such as moisture, acidity, and oil production, resulting in different microbial communities on different areas of the skin.

The gut microbiome is dominated by anaerobic bacteria, with Firmicutes, Bacteroidetes, and Proteobacteria being the major groups. They play crucial roles in digestion, immunity, and overall health.

Commensal bacteria in the gut have a mutually beneficial relationship with the host. They aid in digestion, produce beneficial compounds like short-chain fatty acids, and contribute to immune system development.

Structures and mechanisms bacteria use to infect us, like adhesins for sticking, enzymes for invasion, and toxins for causing damage.

Bacteria with a cylindrical or elongated shape, commonly found in various environments and can cause diseases.

Bacteria with a round or spherical shape, often found in clusters or chains.

Bacteria with a helical or spiral shape, often associated with movement and motility.

A thick, organized layer of polysaccharides surrounding some bacteria, providing protection against phagocytosis and contributing to virulence.

A loose, unorganized layer of polysaccharides surrounding some bacteria, helping with adhesion to surfaces and forming biofilms.

Bacteria with a thick peptidoglycan layer in their cell wall, staining purple in a Gram stain.

Bacteria with a thinner peptidoglycan layer and an outer membrane, staining pink in a Gram stain.

A complex molecule unique to bacteria, forming the cell wall and providing strength and rigidity.

The cell membrane controls what enters and exits the bacterial cell, maintaining the cell's internal environment.

The cell membrane provides a point of attachment for various proteins involved in important functions.

Steroid-like molecules found in bacterial membranes that help stabilize the membrane and maintain its fluidity, similar to cholesterol in eukaryotes.

A network of protein filaments within bacteria that provides structure, helps with shape maintenance, and plays a role in cell division.

A ring-shaped structure made of FtsZ protein that forms at the site of cell division in bacteria, helping to pinch off the dividing cells.

An actin-like protein in bacteria that helps to maintain the cell's length and shape. It's essential for cell elongation.

A filament-like protein that forms a crescent-shaped structure in certain bacteria, giving them their characteristic curved shape.

An actin-like protein involved in chromosome segregation during bacterial cell division, making sure each daughter cell gets a copy of the DNA.

The region in a bacterial cell where the DNA is located. Unlike in eukaryotes, it's not enclosed by a membrane.

A highly resistant, dormant form of some bacteria that allows them to survive harsh environmental conditions.

The process by which bacteria form endospores, involving a series of steps where the DNA is duplicated and protected by multiple layers.

Endospores allow bacteria to survive harsh conditions such as high temperatures, radiation, or lack of nutrients, ensuring survival of the species.

Archaeal flagella are homologous to bacterial flagella but use ATP for energy, unlike bacterial flagella which use the proton motive force. They also rotate like bacterial flagella, not with a whip-like motion like eukaryotic flagella.

Certain archaeal thermophiles possess a reverse gyrase enzyme that introduces positive supercoils into their DNA, protecting it from denaturation at high temperatures.

Bacteria, archaea, and eukaryotes differ in their cell structures and evolutionary histories. Bacteria lack a nucleus and have a simpler internal organization. Archaea share some features with bacteria and some with eukaryotes, while eukaryotes have a nucleus and more complex internal structures.

Archaea and bacteria share similarities in gene regulation and metabolic mechanisms. Both lack a nucleus, have a single circular chromosome, and reproduce mainly through binary fission.

Archaea and eukaryotes share similarities in their DNA/RNA machinery. Both have DNA associated with histones, which help organize and protect their genetic material.

Archaea possess a distinctive modification in their tRNA molecules, where the base archaeosine replaces guanosine.

The core of a virus consists of a viral genome, which can be either DNA or RNA. This genome is encased within a protective protein shell called a capsid.

Many animal viruses are enveloped, meaning they have an outer membrane derived from the host cell's plasma membrane. This membrane surrounds the capsid and helps the virus enter and leave a host cell.

Viruses must carry all the necessary machinery for their own replication, as they rely on the host cell for basic functions. This is crucial for viruses with RNA genomes, as host cells typically lack RNA-dependent RNA polymerase.

Bacteriophages, viruses that infect bacteria, use an enzyme called T4 lysozyme to create a small pore in the bacterial cell wall, allowing the phage's DNA to enter the host cell.

Bacteria come in three main shapes: rod-shaped (bacilli), spherical (cocci), and spiral-shaped (spirochetes).

A sticky outer layer around some bacteria made of sugar molecules. It can be a capsule (thick and organized) or a slime layer (thin and loose).

A thin, flexible layer that acts as a barrier to control what goes in and out of the bacterial cell.

Steroid-like molecules found in bacterial membranes that help stabilize the membrane and maintain its fluidity, similar to cholesterol in eukaryotes.

A tubulin-like protein that forms a ring at the site of cell division in bacteria, helping to pinch off the dividing cells.

An actin-like protein in bacteria that helps to maintain the cell's length and shape. It's essential for cell elongation.

A filament-like protein that forms a crescent-shaped structure in certain bacteria, giving them their characteristic curved shape.

The region in a bacterial cell where the DNA is located. Unlike in eukaryotes, it's not enclosed by a membrane.

A highly resistant, dormant form of some bacteria that allows them to survive harsh environmental conditions.

Archaeal flagella are homologous to bacterial flagella but use ATP for energy, unlike bacterial flagella which use the proton motive force. They also rotate like bacterial flagella, not with a whip-like motion like eukaryotic flagella.

Certain archaeal thermophiles possess a reverse gyrase enzyme that introduces positive supercoils into their DNA, protecting it from denaturation at high temperatures.

Archaea and bacteria share similarities in gene regulation and metabolic mechanisms. Both lack a nucleus, have a single circular chromosome, and reproduce mainly through binary fission.

Archaea and eukaryotes share similarities in their DNA/RNA machinery. Both have DNA associated with histones, which help organize and protect their genetic material.

The core of a virus consists of a viral genome, which can be either DNA or RNA. This genome is encased within a protective protein shell called a capsid.