Microbiology Test 3

Viruses are different from bacteria and require a host cell to reproduce. They are considered obligate intracellular particles.

Viruses typically consist of a nucleic acid-genome, which can be either DNA or RNA, surrounded by a protein coat. The nucleic acid carries the genetic information of the virus, while the protein coat provides protection and recognition for host cell binding.

A virion refers to a fully assembled virus particle that is capable of infecting a host cell. It is the extracellular form of a virus.

The capsid is the protein coat that surrounds the genetic material of a virus, giving it its characteristic shape and symmetry.

Spikes are specialized capsid proteins that play a crucial role in the attachment of viruses to host cells, thereby determining the range of hosts a virus can infect.

A naked virus is one that lacks an outer lipid envelope, consisting only of the nucleocapsid which contains the genetic material.

Helical symmetry refers to a three-dimensional shape that is tightly wound like a coil, such as a cork screw or a spring. It is not a flat, two-dimensional shape like a circle, nor is it an irregular or jagged shape.

Icosahedral viruses are characterized by having 20-sided triangular faces and 12 corners, giving them their distinct geometric shape.

A complex virus refers to a virus that possesses a combination of helical and icosahedral structures, as seen in smallpox virus. This distinguishes them from simpler viruses with single-stranded RNA or linear DNA, or viruses that have an envelope surrounding their genetic material.

The correct answers provide scientifically supported explanations for the origin of viruses based on current understanding of virology and evolutionary biology, while the incorrect answers are not consistent with scientific evidence and lack empirical support.

Viroids are small infectious pathogens that consist only of short strands of RNA and cause diseases in plants by interfering with their gene expression. They are distinct from viruses as they lack a protein coat and are much smaller in size.

TSE stands for Transmissible spongiform encephalopathies, which are a group of progressive, fatal neurodegenerative diseases that affect the brain and nervous system.

Prions are misfolded proteins that can transmit their misfolding to normal variants of the same protein, leading to disease. They are not genetic material or viral particles.

Mad cow disease, also known as bovine spongiform encephalopathy (BSE), primarily affects the brain and nervous system of cattle. Symptoms such as weight loss, unsteadiness, aggressiveness, and lacking coordination are characteristic of the disease and ultimately lead to death. The incorrect answers do not align with the typical symptoms of mad cow disease.

Mad Cow Disease is primarily transmitted to humans through the consumption of contaminated beef, specifically the variant CJD form of the disease.

CJD stands for Creutzfeldt-Jakob disease, a rare degenerative brain disorder that leads to dementia and, ultimately, death. The other options provided do not accurately represent the abbreviation CJD.

The common cold is caused by over 100 different types of viruses, specifically from the Picornaviradae family. These viruses have high mutation rates which make it difficult for the immune system to develop long-term immunity against them.

The symptoms described in the question are classic symptoms of the common cold caused by the Rhinovirus. Laryngitis can sometimes be a complication of the common cold. Pneumonia, Influenza, and Bronchitis have different sets of symptoms and causative agents.

Adenovirus is specifically classified as a group of 50 different naked, icosahedral, dsDNA virus, and not a type of bacteria, single-stranded RNA virus, or a neurological disorder.

Adenovirus is known to cause symptoms such as fever, sore throat, cough, swollen lymph nodes, and a distinct white-gray material on the throat surface. In contrast, Influenza virus primarily causes respiratory symptoms, Rhinovirus is associated with the common cold, and Coronavirus can lead to a range of respiratory issues.

Influenza is a highly contagious acute respiratory illness caused by the influenza virus. It primarily affects the upper respiratory tract and is characterized by symptoms such as fever, cough, and fatigue.

The Influenza family is scientifically known as Orthomyxovirideae, not Retroviridae, Herpesviridae, or Poxviridae.

Influenza protein spikes, specifically Hemagglutinin (H) and Neuraminidase (N), play crucial roles in the attachment, penetration, and release of the virus within host cells.

Influenza viruses are categorized into different types based on their genetic and antigenic properties. The correct answer provides insights into the most common types known to infect humans and animals.

These symptoms collectively point towards a viral infection commonly known as influenza. Influenza is a contagious respiratory illness caused by influenza viruses. Symptoms can range from mild to severe, and can sometimes lead to complications.

Guillian-Barre Syndrome and Reyes syndrome are both types of complications that can arise from Influenza infections. They are not related to autoimmune disorders, bacterial infections, or medication side effects.

Antigenic Drift refers to small changes in the virus caused by point mutations, which are associated with RNA polymerase errors. These changes affect spike proteins, leading to the necessity of developing a new vaccine every year to effectively combat the evolving virus strains.

Antigenic shift refers to major changes in virus structure that result in the creation of a new strain, often with the ability to jump to different species. This process is driven by genetic mutations and can lead to significant public health implications.