topic 2 definitions

• Cell theory


  A concept that defines cells as a fundamental unit of structure, function and organisation in all living organisms
• Cell wall


  A tough outer layer which surrounds some cell types and is made of peptidoglycan in bacteria and cellulose in plants
• Centrioles


  Structures found in the cytoplasm made of microtubules that produce the spindle fibres during mitosis
• Chloroplasts


  Organelles found in plants and algae which are the site of photosynthesis
• Differential staining


  Using multiple different stains to distinguish different parts of a specimen
• Eukaryotic cell


  A type of cell that contains a nucleus along with membrane bound organelles
• Golgi apparatus


  An organelle found in eukaryotic cells that is involved in the modification and packaging of proteins
• Gram-negative bacteria


  A type of bacteria with an outer membrane and a thin inner peptidoglycan cell wall which does not retain the crystal violet stain during gram staining
• Gram-positive bacteria


  A type of bacteria with thick outer peptidoglycan cell walls which retain the crystal violet stain during gram staining
• Light microscope


  A type of microscope that uses a series of lenses to magnify the visible light reflecting off a specimen
• Lysosomes


  Membrane-bound vesicles found in the cytoplasm that contain a hydrolytic enzyme called lysozyme
• Magnification


  How much bigger an image appears compared to the original object calculated using the following formula:
• Mitochondria


  The organelles found in eukaryotic cells which are the sites of aerobic respiration
• Nucleoid


  The area in prokaryotic cells where the chromosomes are found
• Nucleolus


  A dense region found inside the nucleus that contains proteins and RNA and is involved in synthesizing new ribosomes
• Nucleus


  An organelle found in eukaryotic cells that stores the genetic information of the cell as chromosomes and is surrounded by a membrane called the nuclear envelope
• Organ


  A group of specialised tissues working together to carry out a specific function
• Organ system


  A group of specialised organs working together to carry out a specific function
• Permanent vacuole


  A membrane bound structure found in plant and fungal cells that contains cell sap
• Plasmids


  Circular loops of DNA found in the cytoplasm of prokaryotic cells separate from the nucleoid
• Prokaryotic cell


  A type of cell that does not contain any membrane bound organelles or a nucleus
• Resolution


  The ability to distinguish two different nearby points in a specimen
• Ribosomes


  Organelles which are the site of protein production in the process of translation
• Rough endoplasmic reticulum (RER)


  A membrane-bound organelle that is involved in the synthesis and packaging of proteins
• Scanning electron microscope (SEM)


  A type of electron microscope that passes a beam of electrons over the surface of a specimen to produce an image
• Smooth endoplasmic reticulum (SER)


  A membrane-bound organelle involved in lipid synthesis
• Tissue


  A group of specialised cells working together to carry out a specific function
• Tonoplast


  The membrane which surrounds the permanent vacuole
• Transmission electron microscope (TEM)


  A type of electron microscope that passes a beam of electrons through a sample to produce an image
• Acquired Immunodeficiency Syndrome (AIDS)


  A condition caused by HIV which is characterised by a large decrease in proper immune function
• Antivirals


  A class of drugs which work to inhibit viral replication to stop or suppress the infection caused by a virus
• Ebola virus


  An RNA virus which causes major internal bleeding and is spread through contact with bodily fluids of an infected person
• Epidemic


  An infectious disease which has spread to many individuals within a community or region concurrently
• Human Immunodeficiency Virus (HIV)


  An RNA retrovirus which is transmitted through certain bodily fluids like blood or semen and attacks the immune system which can lead to the development of AIDS (acquired immunodeficiency syndrome)
• λ (lambda) phage virus


  A type of DNA virus which infects the bacterium E. coli
• Latency


  The amount of time between exposure to a pathogen and the presentation of symptoms caused by the pathogen
• Lytic cycle


  The replication of a virus within a host cell which ultimately leads to the rupture and death of the host cell
• Pandemic


  An epidemic which has spread over a wider geographical area (typically internationally)
• Tobacco mosaic virus (TMV)


  A type of single stranded RNA virus which infects plant cells and causes discolouration of the leaves in a mosaic-like pattern and hinders their growth
• Anaphase


  The third stage in mitosis where the chromosomes are pulled apart to the poles of the cell by the spindle fibres