Are Viruses Alive, Why or Why not?
No, they are not alive because:
They are not made of
cells
They cannot grow or change
They cannot reproduce on
their own (require a host)
They do not maintain homestasis
How were viruses discovered
Dmitri Ivanosky discovered viruses through tabacco plants, he did not know it was virus, only that it was not a bacteria. Later Martinus Beijerinck repeated the experiment and he coined the term virus. Finally the electron scanning microscope showed us what they looked like!
What are the components of a virus?
Genome/Genetic material , protein capsid, and sometimes lipid envelope
What characteristics are used to classify viruses?
Genomes, Capsid shape, envelope structure in the past
In the present we use the Baltimore system, which uses how mRNA
is produced
Why can't you treat a virus with anti-biotics?
Because antibiotics are designed to specifically work against bacteria, and viruses are not bacteria.
What are the two viral life cycles?
Lytic (reproduce within one cell, hijacking the replication system
and continue to do so until the cell lyses)
Lysogenic -
(reproduce by adding themselves to the dna of the cell, and being
replicated as the cell reproduces, eventually the cell will enter the
lytic cycle)
How do viruses enter cells
Glycoproteins and injection
Glycoproteins and spines
Endocytosis
What is herd immunity and why is it important to get vaccinated
when a large enough portion of the population gets vaccinated, the virus has a difficult time finding suitable hosts for replication, and getting vaccinated protects you and other people
What is a rough timeline of early life on earth
Eurkaryotic 2.1 BYA
Multicell 1.5 BYA
Cambrian SPLOSION 541 MYA
In what domain were the earliest forms of life
Prokarya!
What are the major differences between prokarya and eukarya
prokarya unicellular do not have a nucleus, they do not have membrane
bound organelles, circular chromosome
Eukarya - uni or
multicellular, do have nucleus, do have organelles, have linear chromasome
Difference between bacteria and archaea, which is more closely related to Eukarya
cell wall composition (peptidoglycan) and archaea are often extromphiles, and Archaea are more closely related to Eukarya
how are bacteria able to change their genetic makeup
transformation (environment)
transduction
(phage)
conjugation (wiggle their little bacteria arms at each other)
What is a biofilm and why is their presence problematic for humans
a thin slimy film of bacteria that adheres to a surface. Problematic on our teeth and in pipes in our homes
Are all prokaryotes pathogenic,
no, and we have good ones in our gut
What is bioremediation and what is the role of prokaryotes
bioremediation is the clean up or removal of toxins or heavy metals using organisms that can feed on or break down the problematic stuff
Nitrogen fixing bacteria
the bacteria supply nitrogen to the plants and the plants give us oxygen
Why is kingdom protista a paraphyletic group
includes some but not all recent descendents
What is endosymbiosis and how is it thought to have lead to eukaryotic cells
Endosymbiosis is when one organism lives inside of another to the effect of mutual benefit, and its thought to have lead to eukaryotic cells because mitochondria have their own dna and were probably originally a different organism
What evidence is there that a heterotrophic bacteria was engulfed BEFORE the autotrophic bacteria?
Many protists underwent a secondary endosymbiosis and engulfed photosynthetic prokaryote
what are some distinguishing characteristics of protists
-Diverse group of eukaryotes (don't fit into fungi, animalia, planae)
0unicellular and multicellular
-motile (moved by cilia, flagella, pseudopod)
-micro or macroscopic
- colonial or free living
- hetero or autotrophs (aerobic or anaerobic)
helpful and harmful protists
Zooxanthellae (Dinoflagellates)
Phytoplankton & zooplankton
Brown kelp
Trichonympha
Human pathogens:
Plasmodium
Trypanosoma
Giardia
Plant pathogens:
Plasmopara
Phytophthora
Some distinguishing characteristics of fungi
Eukaryotic, uni or multi cellular, non motile, heterotroph, decomposers
parts of a fungus
hyphae - filamentous tubules that make up most of the mycelium and fruiting bodies - mycellium, network of hyphae
how do fungi reproduce
sexually or asexually, through meiosis or mitosis, with phases
including germination, spore production, and spore distribution
asexual - reproducing same haploid spores (clone)
sexual
combinations of genes from 2 parents that produce spores that are
genetically unique from parents
sexual - Fusion of 2 haploid in plasmogamy, plasmogamy occurs
and hyphae build cells together (dikaryotic) - karyogamy occurs to
unite two nuclei into a diploid cell, the diploid cell immediately
does meiosis to produce 4 spores
clades and examples of fungi
ascomycota - sac fungi yeast and pennicillum
zygomycota -
conjugation fungi - bread mold
Basidiomycota - club and shelf
fungi with fruiting bodies - edible mushrooms
chytridiomycota -
flagella - b/d mass amphibian extinction
Glomeromycota -
symbiotic mycorrhizal fungi - helps trees! ex: Truffles
helpful/harmful fungus
death cap mushroom (harmful) b/d (harmful) yeast (helpful) pennicillum (helpful)
What is the role of fungi in the environment
saprobes/decomposers - they can help in a number of ways like glomeromycota helping trees, decomposing dead animals, returning nutrients to the soil or they can harm the environment like the frog toxin
whats a lichen -
symbiotic association between a fungus and a photosynthetic organism