biology classification

why do we use a binomial naming system?

common names can vary for a single species

how is a scientific name written?

The genus is capitalized, and the whole name is in italics or underlined

who invented binomical nomiclature?

carolus linneaus

7 levels of the Linnaean classification system

Kingdom, Phylum, Class, Order, Family, Genus, Species

(King Phillip came over for great spaghetti)

What are some limitations of the Linnaean classification system?

- it only focuses on physical similarities

- bad because of convergent evolution

what is a phylogeny?

it shows how each member of the family is related to other members

what are the three domains?

Archaea, Bacteria, Eukarya

bacteria

single-celled organisms that lack a nucleus; prokaryotes

archaea

single-celled prokaryotes

extremophiles

no organelles

differ from bacteria in cell wall structure and genetics

eukarya

eukaryotes

single-celled or multicellular

includes plants, animals, fungi, protists

what are the 6 kingdoms?

Plants, Animals, Protists, Fungi, Archaebacteria, Eubacteria

why is cladistics a work in progress and what information do we currently rely on for current data?

new findings can lead scientists to change how they classify organisms.

we rely on molecular data

why are viruses not considered alive?

they cannot reproduce on their own or carry out thier own metabolic processes

what are viruses made out of?

- DNA or RNA

- Double or single stranded

- Surrounded by a capsid (protein coat)

- Viral envelope (lipid bilayer)

- Surface proteins that aid infecting host cells

what are the different shapes of capsids?

helical (rod shaped), polyhedral, or more complex (bacteriophages)

what is a single virus particle called?

virion

How is the "host range" determined?

it fits in surface proteins to receptor molecules on the host cell surface

what does a virus do upon entering a host cell?

it manufactures viral proteins

what is a bacteriophage?

a virus that infects bacteria

lysogenic cycle

- replicated phages WITHOUT destroying the host

- viral DNA Is incorporated into host cell's chromosome and called a prophage

- replicates with the host

lytic cycle

- kills the host cell

- virus replicated and then leaves

- causes cell to lyse or burst

how do vaccines work to prevent illness?

vaccines are harmless versions of pathogenic microbes

they stimulate the immune system to mount defense against the actual pathogen

why can't you take antibiotics for a virus?

antibiotics are meant to kill bacteria, not viruses

viruses do not have a cell wall for the antibiotics to attack, they instead have a protective protein coat

what are some common viral diseases?

Common cold, influenza, pneumonia, and hepatitis

how does the structure of prokaryotes differ from the structure of eukaryotes?

prokaryotes are smaller and lack membrane bound organelles

what is the bacterial cell wall made out of?

peptidoglycan

structure of bacteria

unicellular prokaryotes

spheres (cocci), rods (bacilli), spirals (spirilla)

what does a gram stain result tell us?

gram-neg bacteria have less peptidoglycan and stain lighter than gram-pos bacteria

how do prokaryotes move?

flagella and pili

how can prokaryotes be grouped based off their need for oxygen?

obligate aerobe - requires oxygen

obligate anaerobe - no oxygen

facultative anaerobe - survives without oxygen when necessary

how do prokaryotes reproduce?

binary fission

- high diversity from mutations allows for rapid evolution

what is an endospore and why does it help bacteria survive?

an endospore is a thick and protective wall formed around a copy of the bacteria's DNA

it prevents it from drying out, temperature changes, and disinfectants

why do mutations build up so quickly in prokaryotes?

- short generation times

- haploid

what is conjugation and how does it impact bacterial evolution?

genetic material is transferred between bacterial cells and it increases genetic diversity

ecological roles of bacteria

- decomposing (break down corpses, dead vegetation, and waste products)

- nitrogen fixation (convert nitrogen in atmosphere to usable nitrogen for plants)

- bioremediation (breaking down of pollutants)

- photosynthesis (cyanobacteria produce oxygen through it)

what are some bacterial diseases?

Salmonella, gonorrhoea, strep, tetanus, tuberculosis

how does antibiotic work and why doesn't it affect human cells?

it interferes with the peptidoglycan cell wall of bacteria

animal cells don't have a cell wall so they don't impact our cells

what are two ways that bacteria can make us sick?

- by invading tissues and attacking cells

- making toxins (common cause of food poisoning)

what is antibiotic resistance and how does it occur?

when the bacteria stops responding to the antibiotic

it occurs with overuse, underuse, and misuse of the antibiotic.

what are prions and what animals are infected?

prions are slow acting, indestructible infections proteins that cuase brain disease in mammals

- they happen in sheep (scrapie), Cruetzfeldt-Jakob disease in human

why is kingdom protista so difficult to classify?

they aren't actually related to each other but they are all eukaryotic, and not animal, plant, or fungi.

characteristics of protists?

eukaryotic

unicellular/multicellular

autotrophic or heterotrophic

move or stationary

usually live in aquatic environments

how do protists move?

pseudopods, cilia, flagella

how do protists reproduce?

mitosis (limits genetic diversity)/ meiosis

conjugation

what is alternation of generations in protists?

The change in generation between haploid and diploid form (sexual and asexual)

ecological role of protists

algae

mutualistic symbiosis

parasitic protists

what are some common diseases caused by protists?

malaria, sleeping sickness, amoebic dysentery

how do plants and fungi differ structurally + how they obtain energy?

fungi do not have chloroplasts so they ABSORB food from their environment

plants have true roots, leaves, and stems, fungi do not

plant walls are made out of cellulose, while fungal cell walls are made out of CHITIN

are fungi multicellular or unicellular?

multicellular or unicellular (yeast)

anatomy of a fungus

- composed of long filaments called HYPHAE

- hyphae tangled underground is called a mycelium

- mycelia produce fruiting bodies (reproductive structures) above ground

how do fungi reproduce?

fungi reproduce sexually when conditions are harsh

they reproduce asexually when conditions are favorable

life cycle of fungi?

spores germinate into hyphae, forming mycelium, which can reproduce asexually or sexually, producing more spores

sac fungi

yeast, penicillium, morels, truffles

they have a sac called an ascus that contains spores for reproduction

bread molds

- spoil food

- during sexual reproduction they form a zygospore which rises to a sporangium which releases spores

club fungi

- mushrooms, puffballs, and shelf fungi)

- during sexual reproduction, they form basidia that contain spores

ecological role of fungi

- decomposers

- pathogens

- mycorrhizae is a mutualist to plant roots

- lichens provide minerals to photosynthetic partner

common diseases caused by fungi?

athlete's foot, ringworm, peach scab, gray mold, Dutch elm disease