Term 1 Biomedical Sciences Quiz 1

Bacteria

• Are prokaryotes, meaning they don't have a nucleus.
• Use a structure called flagellum to move.
• Can cause oral conditions like Caries and Periodontal disease.
• The cell wall of gram-negative bacteria produces endotoxins during cell lysis.
• The cell wall of gram-negative bacteria does not produce endotoxins whilst the bacteria is replicating

Cell Structure

• Microflora would not be expected to be found in cell structure.

Golgi Apparatus

• Produces secretory enzymes, plays a key role in the secretory pathway, and packages and processes proteins.
• It does NOT play an important part in cell division.

Nuclear Envelope

• The outer layer is not covered with cilia.
• The outer layer is continuous with the endoplasmic reticulum, and is a double membrane.
• Pores in the membrane allow the passage of substances.

Nucleus

• The nucleus stores genetic material, directs all metabolic activities and involved in cell division.
• The nucleus is not the smallest feature in a cell.

Cells

• The cell is the smallest functional unit in the body.

Plasma Membrane

• The shape and structure of a cell depends on the function it performs.
• All cells have a nucleus with the exception of mature erythrocytes.
• It is false to suggest the plasma membrane comprises a single layer.

Mitosis

• It has 5 stages
• It is the process by which a cell duplicates the chromosomes in the cell nucleus.
• Each daughter nuclei does not contain 34 chromosomes

Organelles

• Lysosomes contains enzymes to digest foreign material.
• The powerhouse of the cell is the mitochondrion.

Fungi

• Fungal microflora is present throughout the human body.
• The diversity of fungal presence varies from person to person and will not remain the same for all sites on an individual.
• Yeast and mould are structural forms fungi.
• Fungi are oral commensals of approximately 50% of humans, are eukaryotic organisms and fungal mycelium contains an abundance of hyphal elements.
• The term dimorphic relates to the ability of fungi to switch between being a yeast and a mould.
• The term commensal microflora does not refer to the pathogenic nature of micro-organisms to the host.

Bacteria vs Yeast

• Yeast is unlike bacteria in being unicellular and eukaryotic.

Viruses

• Herpes zoster is an example of a virus exhibiting viral latency.
• The genetic material can be RNA, DNA
• Penetration occurs via Translocation, Fusion, Endocytosis

Viral Replication

• The correct order of replication is: Adsorption, Penetration, Uncoating, Transcription, Synthesis of viral components, Assembly, Release.
• Viruses are predominantly made out of proteins.

Virus Multiplication

• Viruses can only multiply by asexual reproduction.
• Viruses cannot reproduce without a host, do not metabolise food into energy, and do not have organised cells.
• They are not classes as living things.

Pathogens

• In order to survive, pathogens require a source of nutrients, protection from harmful elements and colonization of a niche in the host.
• Some enveloped viruses use antigenic variation which makes it difficult for the immune system to recognise different strains of the virus.
• Antigenic shift is the type of antigenic variation results in a major change in spike proteins due to gene reassortment

Pathogen Types

• Opportunistic pathogens are always a member of the normal microbiota and only causes disease in an immunocompromised host.
• Primary pathogens are environmental microbes that is able to cause disease in an otherwise healthy individual.

Virulence Factors

• Virulence factors are a factor that helps an organism to invade a host, mechanisms that determine the degree to which the pathogen causes damages, and factors which enable a pathogen to infect a host.
• All of the above.
• Proteases, nucleases, phospholipases and glycohydrolases are exoenzymes.
• Proteins F and A, Pili and Fimbraie act as adhesins.
• Adhesins assist in promoting colonization of the host.
• Toxins and exoenzymes enable damage to be caused to the host.
• Porphyromonas Gingivalis leads to disregulated immunity via Fimbraie and exoenzyme Gingipains, which leads to disregulated immunity in the gingival tissues and breakdown of the structures around the teeth.
• Microbes are the most abundant organisms on the human body.
• Antibiotics are the type of medicine which kills bacteria.