diversity Flashcards
prokaryotic (before the nucleus)
- no membrane-bound nucleus
- simpler internal cell structure
- smaller
eukaryotic (true nucleus)
- membrane bound nucleus
- more complex internal cell structure
- larger (up to 100x)
binomial nomenclature
- refers to two-part naming system
- an organisms scientific/species name
TWO PARTS:
GENUS: identifies group of closely related species which species belongs to
SPECIES: scientific name is italicized, genus name capitalized, species name lower case
hierarchy
- DOMAIN (eukarya)- cells w/ nuclei
- KINGDOM (animalia)- multicellular, motile, ingest food
- PHYLUM (chordata)- dorsal supporting rod and nerve cord
- CLASS (mammalia)- hair, mammary glands
- ORDER (primates)- adapted to climb trees
- FAMILY (hominidae)- adapted to walk erect
- GENUS (homo)- large brain, tool use, more characteristics in common
- SPECIES (homosapiens)- body proportions of modern humans
6 kingdoms + characteristics
- ARCHAEA: prokaryotic; unicellular organisms; bacteria-like micro-organisms that thrive in extreme environments
ex: volcanoes, in acidic/salty environments - BACTERIA: prokaryotic; unicellular organisms; micro-organisms that thrive in moderate environments
ex: anthrax - PROTISTA: eukaryotic; unicellular and multicellular organisms that aren’t in plants/animals
ex: amoeba, algae - FUNGI: eukaryotic; mostly unicellular, digest food then absorb nutrients through cell membranes
ex: mushrooms - PLANTAE: eukaryotic; use photosynthesis (autotrophs) to make food
ex: roses - ANIMALIA: eukaryotic; heterotrophic; can move around to obtain food, digestion, and absorption is internal
ex: humans
difference between Archaea and Bacteria
ARCHAEA:
- 1st cells to evolve
- live in harsh environments
- found in: sewage treatment plants, thermal/volcanic vents, hot springs/geysers that are acid, very salty water
BACTERIA:
- some may cause disease
- found in all habitats except harsh ones
- important decomposers for environment
- important in making cottage cheese, yogurt, buttermilk
bacteria
- smallest independently living organisms
- most abundant living organisms
- can be beneficial or disease-causing
- diverse in abilities to live in different environments
structure of typical bacterium
- unicellular, prokaryotic (lack membrane bound organelles)
- no chromosomes, have a single circular DNA loop
- small ribosomes
- cell wall made of material called peptidoglycan
bacteria shapes
COCCI: round
BACILLI: rod-shaped
VIBRIOS: curved rods
SPIRILLA: helical shape, rigid bodies
SPIROCHETES: helical shape, flexible bodies
DIPLO: cells in pairs
TETRAD: cells in groups of 4 (cocci)
SARCINAE: cells in groups of 8 (cocci)
STREPTO: cells in chains
STAPHYLO: cells in grape-like clusters (cocci)
FLAGELLA: tail-like
gram stains classification (crystal violet)
show differences in amino acids and sugar molecules
GRAM-POSITIVE: purple, thick wall
- thickness blocks escape of crystal violet-iodine complex when cells washed with alcohol or acetone
GRAM-NEGATIVE: pink, thin layer of peptigdoglycan
- can’t retain dye upon washing
binary fission
form of asexual reproduction which organism divides into two, carrying one copy of genetic material
conjugation
DNA (from a plasmid) passes from one bacterium to another via a structure called a pilus
what is a virus
non-cellular particle made up of DNA/RNA and a protein coat (capsid) that can invade a living cell
viruses
- dependent on internal physiology of cells
- not cellular, lack cytoplasm, organelles, and cell membranes
- virus must infect a host cell in order to be functional
viral structure of viruses
POLYHEDRAL: many-sided, nucleic acid core surrounded by protein in coat called capsid
- ex: rhinovirus
HELICAL: rod like symmetry, nucleic acid is enclosed in a hollow cylindrical capsid
- ex: tobacco mosaic virus, rabies
ENVELOPED: membrane coat surrounding capsid, roughly spherical
- ex: influenza virus
COMPLEX: neither helical or polyhedral, but a combination
- ex: poxvirus
ADENOVIRUS: common cold
BACTERIOPHAGE: virus that infects bacteria
lytic cycle
- attachment: virus attaches to body of cell
- entry/injection: virus invades host cell, injects viral DNA/RNA
- replication: host cell makes copies of new viral proteins
- assembly: new viral particles put together
- lysis and release: new viral particles released into environment when able to invade new cells
lysogenic cycle
- some viruses have ability to remain dormant inside cell; called latent viruses
- remain inactive for long periods of time, even years
- later they activate to produce new viruses in response to an external signal
- at that point they go into lytic cycle
ex: HIV or Herpes
incubation period
time it takes between when virus infects a cell when symptoms appear
retroviruses
carry RNA and an enzyme called reverse transcriptase that causes host cell to copy viral RNA into DNA
- then embeds into hosts chromosomes and becomes provirus
- each descendent cell
how do vaccines work
releases antigen into body, imitates infection and teaches immune system how to respond and fight off diseases
- helps protect person from diseases and getting sick
what is the function of antibiotics
fights infections caused by bacteria in humans/animals by killing bacteria or making it difficult for it to grow/multiply
when you are prescribed antibiotics, why must you finish the medication completely
must finish completely to prevent the infection from returning again and prevention of antibiotic resistance
