microorganisms and disease Flashcards
microorganisms
cannot be seen with the naked eye; classified as bacteria, viruses, fungi, protozoa (including algae), or animals
protists
unicellular eukaryotes that feed on other cells.
largest group of organisms in the world in terms of numbers, biomass, and diversity.
diseases: dysentery, malaria and sleeping sickness.
parasites
live on or in the body of a larger organisms called the host and derive most of its sustenance from that host.
pathogen
an infectious agent that damages the host through infection and disease.
bacteria
prokaryotic (lack a nucleus)
can cause disease, or are harmless
ex: tuberculosis. meningitis, food poisoning.
viruses
noncellular entities that consist of either DNA or RNA surrounded by a protein coat.
nonliving
cause diseases: the flu, measles, mumps, HIV, and Covid
fungi
eukaryotic decomposers
some cause diseases to humans like asthma, athletes’ food, ringworm, lung infections, and blood stream infections.
animals
parasitic worms known as helminths.
live in many areas of the body
flatworms (tapeworms): live in the intestines.
roundworms: survive in the gastrointestinal tract and lymphatic system.
infectious/communicable diseases
spread from one person to another.
caused by pathogenic microbes such as bacteria, protists, viruses, etc.
ex: cholera, chickenpox, and covid
non-infectious diseases
diseases that cannot be transmitted directly from one person to another.
not caused by pathogens!!
caused by age, nutritional deficiency, gender, and lifestyle.
ex: diabetes, cancer, and asthma.
how do infectious diseases spread
direct contact with a sick individual, skin-to-skin contact (sexual contact too), contact with bodily fluids, or touching common surfaces.
what are the most common types of microscopes
light and electron
electron microscope
forms an image using beans of electrons that travel in a wavelike pattern.
greater resolution than light microscopes.
does not work on living cells.
two types: TEM, and SEM
light microscope
depend on a light source
six types: bright field, dark-field, phase contrast, fluorescence, confocal scanning laser (CSLM), and differential interference contrast microscope (DIC).
