chapter 16 Flashcards
Prokaryotes are
Single celled organisms which lack nucleus and membrane bound organelles
Prokaryotes, they are considered to be the most,
Ancient and simplest life-form
What are the two domains,
Archaea, bacteria
Prokaryotes
- 1-5um in diameter
- are found wherever there is life
- outnumber all eukaryotes conbined
- can cause disease
- can be beneficial
- have no organelles
What are the 3 forms of prokaryotes
Cocci Bacilli and spirochete
Nearly all prokaryotes have a ________
cell wall
The cell wall in a prokaryote can…..
- provide physical protection
- prevent the cell wall from bursting in a hypotonic environment
When gram stained, cell walls of bacteria are either
- gram-positive, with more layers of peptidoglycan
- gram-negative, with less peptidoglycan, however a more complex cytoplasmic membrane and more likely to cause diseases
The cell wall of many prokaryotes is covered by a _______, a sticky layer of polysaccarides or protein.
Capsule
__________: enables prokaryotes to adhere to their substrate or to other individuals in a colony and shields pathogenic prokarotes from attacks by a hosts immune system
Capsule
_________ help prokaryotes move in their environment.
Flagella
what are the modes of nutrition.
Photoautotrophs
- photoheterotrophs
- chemoautotrophs
- chemoheterotroph
Photoautotrophs
Obtain energy from sunlight and use carbon dioxide for carbon
Photohereotrophs
obtain energy from sunlight but get their carbon atoms from organic molecules
Chemoautotrophs
Harvest energy from inorganic chemicals and use carbon dioxide for carbon
Chemoheterotrophs
Acquire energy and carbon from organic molecules
______: are complex associations of one or several species of prokaryotes
Biofilms
Prokaryotes attach to surface and form biofilm communities and are ___________.
difficult to eradicate
Biofilms are larger complex “cities” of microbes that……
_ comminicate by chemical signals, coordinate a divison of labor & defense, and use channels to distribute nutrients and collect waste.
________ is the use of organisms to remove pollutants from soil, air, or water
bioremediation
The domain Bacteria is currently divided into five groups, based on comparisons of genetic sequences
Proteobacteria
- Gram-positive bacteria
- cyanobacteria
- chlamydias
- spirochetes
Proteobacteria
All gram negative bacteria, diverse, some are symbiotic with legumes (N2 fixers)
Gram-postive bacteria
As diverse as proteobacteria
Cyanobacteria
The only group of prokararyotes with plantlike, oxygen-generating photosynthesis. some are N2 fixers
Chlamydias
intercellualar bacteria that live inside eukaryotic host cells
Spirochetes
Are helical bacteria and notorious pathogens, causing syphilis and lyme disease
All organisms are almost constantly exposed to____________.
pathogenic bacteria
_________ are proteins that bacterial cells secrete into their environment.
Exotoxin
_________ are components of the outer membrane of gram-negative bacteria
Endotoxin
Extreme_______ thrive in very salty places
Halophiles
extreme______ thrive in very hot water, such as geysers, and acid pools
thermophiles
___________: live in anaerobic enviroments, and give off methane as a waste product from the digestive tract of cattle, deer, and in decomposing materials of landfills.
Methanogens
________: are diverse collection of mostly unicellular eukaryotes. this is refer to eukaryotes that are not plants, animals or fungus, however they often share some similarities to these eukaryotes
Protists
Protists are found in many habitats including……
- anywhere there is mosture
- the bodies of host organisms
_______: autotrophs which produce their food by photosynthesis
Algae
________: heterotrophs which eat bacteria and other protists
Protozoans
________: heterotrophs which derive their nutrition from a living host
Parasites
________: use photosynthesis and heterotrophy
Mixotrophs
The _________________ explains the orgin of mitochondria and chloroplasts
Endosymbiont theory
Eukaryotic cells evolved when prokaryotes established residence with other, larger ____________
Prokaryotes
The endsymbiont theory is supported by present-day ___________ and _____________.
mitochodria
chloroplast
Support for Endosymbiosis includes
- structural and molecular similarities to prokaryotic cells
- replication and use their own DNA, separate from the nuclear DNA of the cell
The process in which an autotrophic eukaryotic protist became endosymbiotic in a heterotrophic eukaryotic protist
Secondary endosymbiosis
are a larger supergroup including autotrophs, heterotrophs, and mixotrophs
Chromalveolates
What are some representatives of chromalveolates
- diatoms
- dinoflagellates
- brown algae
- water molds
- ciliates
- plasmodium
___________, unicellular algae with a class cell wall containing silica
Diatoms
__________, unicellular autotrophs, heterotrophs, and mixtrophs that are common components of marine plankton
Dinoflagellates
__________, large, multicellular autotrophs
Brown algae (kelp)
Other chromalveolates include
- water mold
- ciliates
- plasmodium
Water molds
unicellular heterotrophs
Ciliates
Unicellular heterotrophs and mixotrophs that use cilia to move and feed.
a group including parasites, such as ________ which causes malaria
Plasmodium
__________ are a claude (group) grouped together by DNA similarites
Rhizarians
Rhizarans include ___________&___________ which are often referred to as amoebas
Foraminiferans
Radiolarians
__________: are found in the oceans and in fresh water
Foraminiferans
Foraminiferans have porous shells called ______, composed of calcium carbonate
Tests
_________ are mostly marine, produce a mineralized internal skeleton made of silica
Radiolarians
__________ is a new clade on the basis of molecular and morphological simiarities
Excavata
___________: have modified mitchondria that lack functional electron transport chains and use anaerobic pathways such as glycolysis to extract energy
Excavates
Excavates include.
- heterotrophic termite endosymbionts
- mixotrophs such as Euglena
- the common waterborne parasite giardia intestinails,
- the parasite trichomonas vaginalis, which causes 5 million new infections each year of human reproductive tract
- the parasite trypanosoma, which causes sleepinmg sickness in humans
______________ is a grouping considered closely related to fungi and animals, it inculdes some amoebas and slime molds
Unikonts
Plasmodial slime molds
- are common where there is moist, decaying organic matter
consist of a single, multinucleate mass of cytoplasm undivided by plasma membranes, called ____________.
Plasmodium
___________: are common on rotting logs and decaying organic matter and usually exist as solitary amoeboid cells, but when food is scarce, amoeboid cells
Cellular slime molds
Swarm together, forming a slug-like aggregate that wanders around for a short time and then forms a stock supporting an asexual reproduction structure that produces _________.
Spores
Archaeplastide include
- red algae
- green algae
- land plants
Red algae
- are mostly multicellular
- contribute to the structure of coral reefs
- are commercially valuable
green algae
may be unicellar, colonial or multicellar
Multicellular organisms are fundamentally different from __________ organisms
Unicellular
a _________ organism has various specialized cells that perform different functions and are interdependent
Multicellular
All of lifes activities occur within a single cell in __________ organisms
unicellular
multicellular organisms have evolved from three different lineages
- brown algae evolved from chromalveolates
- fungi and animals evolved from unikonts
- red algae and green algae evolved from achaeplastid
One hypothesis states that two separate ________led to fungi and animals, diverging more than 1 billion years ago
Unikont
Morphological and molecular evidence suggest that _________ are the closest living protist relative of animals
Choanoflagellates
