Chapter 19&27&28 Flashcards
non-living infectious particles that can reproduce
viruses
needing to use the inside of a host cell to reproduce- can replicate only within a host cell
obligate intracellular parasites
only infect bacteria
bacteriophages
a virus consists of a ___ surrounded by a ____
nucleic acid, protein coat
protein shell, wraps around the DNA or RNA
capsid
viruses can only infect ___ cells from specific species
specific
slow-acting, non-living, virtually indestructible infectious proteins that cause brain diseases in mammals
prions
propagate by converting normal proteins into the altered prion version
prions
Bacteria and Archaea belong to this group
Prokaryotes
Prokaryotes are ____, meaning they are everywhere
Ubiquitous
difficult to study because they love extreme environments (extremophiles)
archaea
Archaea are different from bacteria because of these 3 things
membrane structure, metabolic, and transcription/translation related genes
Most prokaryotic cells are about ___- ___x smaller than eukaryotic cells
10-100x
Earth’s first organisms were likely this
prokaryotes
The three most common shapes of prokaryotes are…
cocci (spheres), bacilli (rods), and spirals
DNA shaped as a ring (prokaryote)
circular chromosome
structure for a cell
cell wall *some of these structures are present in all bacteria, others depend on the type
used to exchange DNA between bacterial cells
sex pilus
movement
flagella
make proteins
ribosomes * some o these structures are present in all bacteria, others depend on the type
thick protective layer outside of some bacteria
capsule
hairs that help attach bacteria to surfaces
fimbriae
The 2 types of cell wall in a bacterial structure
gram positive and gram negative
has a cell wall structure that has one membrane, and thick layer peptido-glycan layer
purple color
gram positive
two membrane with a skinny layer of peptido-glycan layer with an outer membrane
pink color
gram negative
in a heterogeneous environment, many bacteria exhibit ___, the ability to move toward or away from a stimulus
taxis
the movement toward or away from a chemical stimulus
chemotaxis
The prokaryotic genome has less ____ than the eukaryotic genome
DNA
smaller rings of DNA
plasmids
most of the genome consists of a circular _____
chromosome
asexual reproduction. Prokaryotes reproduce quickly by ___ ___ and can divide every 1-3 hours
binary fission
cells essentially identical to the parent
daughter cells
longer than fimbriae and allow prokaryotes to exchange DNA usually on plasmids
sex pili
carry genes for antibiotic resistance
R plasmids
prokaryotes are the principal agents in ____, the use of organisms to remove pollutants from the environment
bioremediation
informal name of the group mostly unicellular eukaryotes
protist
protists constitute a ____ group, and are closely related to plants, fungi, and some animals. Protista is no longer valid as a kingdom
polyphyletic group
Protists are eukaryotes or prokaryotes?
eukaryotes
Most eukaryotes are ___-celled organisms
single
Almost all protists are multicellular or single cellular?
single cellular
type of protist that contains chloroplasts, and performs photosynthesis
photoautotrophs
type of protist that absorbs organic molecules or ingests larger food particles
heterotrophs
type of protist that combines photosynthesis and heterotrophic nutrition
mixotrophs
the process in which a unicellular organism engulfs another cell, which becomes incorporated with the host cell and eventually becomes an organelle
endosymbiosis
protist ____ benefit their hosts, involving interaction between two different organisms living in close physical association
symbiont
____ protist will live within another organisms and harm it in some way to their own benefit
parasitic
