fungi and parasites Flashcards
(15 cards)
How are fungi different from other microbes?
Fungi are eukaryotic, can be unicellular or multicellular, have chitin in their cell walls, and absorb nutrients externally using hydrolytic enzymes.
What are the structural features of fungi?
They include a chitin-based cell wall, glucans, mannose-bound proteins, plasma membrane with ergosterol, and typical eukaryotic organelles.
How does the fungal cell wall differ from bacterial cell walls?
Fungal cell walls contain chitin and glucans, while bacterial cell walls primarily contain peptidoglycan.
What are the main types of fungal reproduction?
Fungi reproduce asexually (budding, fission, fragmentation, spore formation) and sexually (involving mating types and spore formation under stress).
What is dimorphism in fungi?
It is the ability of fungi to exist in two forms; e.g., as hyphae in the environment and as yeasts in host tissues.
What are common fungal diseases (mycoses)?
Examples include dermatophyte infections (tinea), candidiasis (oral, vaginal, systemic) caused by Candida albicans.
What is a parasite?
A parasite is an organism that lives on or in a host and gets its food from or at the expense of the host.
What are the three major classes of human parasites?
Protozoa, Helminths, and Ectoparasites.
What are the key features of protozoa?
Protozoa are single-celled eukaryotes with organelles, often transmitted via fecal-oral route or vectors, and may form protective cysts.
How are protozoa classified based on movement?
Amoeboid (pseudopodia), Flagellates (flagella), Ciliates (cilia), Sporozoa (non-motile adult stage).
Describe the infection cycle of Plasmodium (malaria).
Transmitted by mosquitoes; sporozoites infect liver, then red blood cells; cycles of rupture cause symptoms like fever and chills.
Describe the infection caused by Toxoplasma.
Transmitted via undercooked meat or cat feces; can be serious in immunocompromised people and pregnant women.
What is threadworm and how is it transmitted?
Threadworm (Enterobius vermicularis) is a helminth spread by ingesting eggs; causes anal itching especially at night.
What are ectoparasites?
Parasites that live on the surface of the host such as lice, ticks, mites, and fleas; often arthropods and vectors for other pathogens.
How can parasitic infections be prevented?
Through good hygiene, cooking food thoroughly, wearing shoes, avoiding contaminated water, and controlling vectors like mosquitoes.
