Flashcards in L9 - Viruses and Eukaryotes Deck (13):
What is the outer layer of a virus called and what is it made up of?
Capsid- made up of protein subunits called capsomeres
What is the outer coat of some viruses made up of?
Surface proteins and lipids
Name and briefly describe the intracellular and extracellular versions of a virus
Extracellular = viron/virus = inert particles carrying out neither metabolic or biosynthetic activities
intracellular = once intracellular the virus DNA/RNA becomes active and replicates inside the host
What 2 types of lifecycle can a virus have? Describe each briefly
1) lytic - once inside the cell, the virus replicates its DNA and capsids, puts the DNA inside the capsid then lyses the cell and the phages are released
2) lysogenic - once inside the cell the viruses DNA integrates into the hosts DNA, so when the cell replicates the virus is replicated as well
What is a viron?
A viron is a small circular single stranded RNA - smallest know pathogen
Important plant protein
What is a prion?
A prion is an extracellular infectious protein
Causes scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle and kuru and new variant form CJD in humans.
What is the structure called how most fungi grow?
What is meant by the fact fungi are dikaryons?
Their + and - nuclei fuse, undergo meiosis and form fruiting bodies
Briefly describe Chytridio-mycota
Play a key role in the breakdown of rumen in cows.
Can be a lethal parasite to tree frogs
Don't have hyphae
Briefly describe Zygomycota
Mostly saprotrophs, some important plant (Rhizopus) and human (Mucor, Absidia) pathogens
Have broad hyphae
Asexual spores produced in pin-head-like sporangia
Briefly describe Glomero-mycota
Widespread on roots of herbaceous plants (earliest known fossil fungi), share nutrients
Briefly describe Ascomycota
Have spetated hyphae
These produce 8 ascospores in sac-like asci.
Include cup fungi – but also yeasts and many micro fungi.
Many are important plant pathogens.