Chap 15 Evolution and Diversity of Microbial Life Flashcards
Organic molecules form what?
simple chemicals
What happened in Miller’s experiments?
scientists applied electricity to a mix of simple chemicals that made up early earth’s atmosphere and those chemicals combined to form organic molecules like nucleotides and amino acids
What were the first cells?
prokaryotes
How were organic molecules enclosed in early prokaryotes?
by a phospholipid membrane
What type of cells arose around 1.5 billion years ago?
eukaryotic
What is the hypothesis of how the nucleus formed?
the membrane folded in on itself, pinched off, created a nuclear membrane around genetic material
What process explains the origin of the mitochondria and chloroplasts?
endosymbiosis
What is endosymbiosis?
aerobic bacteria (and later photosynthetic cyanobacteria) took up residence inside ancient host cells
What are the things that make prokaryote diverse?
shape
endospores
metabolism
What are the different metabolisms that contribute to prokaryote diversity?
autotroph vs heterotroph
aerobic vs anaerobic
What are autotrophs?
get carbon from inorganic sources, typically CO2
What are heterotrophs?
get carbon by consuming other organisms
What is aerobic respiration?
uses O2 to produce ATP
What is anaerobic respiration?
can produce ATP in the absence of O2
What determines the cell shape?
the cell wall
What are the three most common shapes for bacteria?
coccus (spherical)
bacillus (rod-shaped)
spirillum (spiral)
What keeps some bacteria alive?
endospores
What are endospores?
thick walled parts of bacteria that can survive harsh conditions
Obligate aerobes require what to survive?
oxygen
Obligate anaerobes a killed by what?
oxygen
What are facultative anaerobes?
can live in aerobic or anaerobic environments
What are essential to life (type of life)?
bacteria and archaea (prokaryotes)
Where so prokaryotes live?
everywhere
What are some of the functions of prokaryotes?
contribute gases to the atmosphere
recycle organic matter
fix nitrogen
All other species would die without what?
prokaryotes
Some bacteria cause what?
disease
How can harmful bacteria enter the body?
ingested
inhaled
through wounds or other orifices
Humans use what?
prokaryotes
How do humans use prokaryotes?
their natural metabolism helps make certain foods
transgenic bacteria produce many important drugs
microbes can break down organic matter in waste water treatment plants
What are the simplest eukaryotes?
protists
Why is classifying protists difficult?
they are not single clad, it is not clear if they are a true kingdom
How were protists originally defined?
eukaryotes that are not plants, fungi, or animals
What became more available causing protists to be reclassified into dozens of new groups?
new DNA data
What are photosynthetic protists?
algae
Where do algae live?
in water
What do algae do?
produce much of earth’s O2
support food webs in water bodies
What are protists with flagella?
dinoflagellates
dinoflagellates are characterized by what?
two flagella (use them to whirl around the ocean)
What are the different characteristics of some dinoflagellates?
some photosynthetic
some live inside animals
some bioluminescent
can overgrow and produce toxins (red tides)
What do algae do when they are disturbed?
release light
algae are disturbed by what?
copepods
What is the food chain of algae?
algae eaten by copepods (herbivore)
copepods eaten by stickleback (fish, predator)
What are algae with unique silica cell walls?
diatoms
Where do diatoms live?
oceans
Diatoms are crucial for source for what?
photosynthesis
food for zooplankton
What is special about the cell walls of diatoms?
they are very intricate giving them unique shapes
What are the most complex and largest protists?
brown algae
Brown algae is single or multi cellular?
multi cellular
Where do brown algae live?
marine habitats all over the world
Which algae share many features with plants?
red and green algae
What is similar between green algae and plants?
use the same photosynthetic pigments
habitats and body forms are diverse
may be unicellular, filamentous,, colonial, or multicellular
What are diverse heterotrophic protists?
protozoa
How are protozoa grouped together?
based on morphology and locomotion (only distantly related to each other in terms of DNA sequence)
What are essential decomposers?
fungi
Fungi are more closely related to plants or animals?
animals (look like plants but share many chemical and metabolic features with animals)
What are the planet’s garbage processors?
fungi
What do fungi do?
break down dead plants and animals, releasing nutrients to be recycled
What are fungi made of?
hyphae and fruiting bodies
What is the fruiting body?
above ground part of fungi, it produces spores (microscopic reproductive cells)
What is the hyphae?
network of underground filaments of fungi
Collectively the hyphae is called what?
mycelium
What do humans use fungi for?
food
medicine
What type of fungi gives food delicious flavors?
basidiomycetes
ascomycetes
What type of fungi is used to produce wine and beer?
yeasts
Ascomycetes are famous for what?
secreting the antibiotics penicillin and cyclosporine
Some fungi are what?
pathogenic
What does it mean the some fungi are pathogenic?
cause fungal diseases
What are some illnesses caused by infectious fungi?
pneumonis
ringworm
athlete’s foot
Fungi and plants form what?
mycorrhizae
What are mycorrhizae?
structures that allow plants and fungi to share materials with each other.
How do fungi and plants use mycorrhizae?
the fungi absorb water and minerals while the plant produces carbohydrates in photosynthesis
What is the name for dual organisms?
lichens
What are lichens?
fungi with green algae or cyanobacteria living among their hyphae
What do the lichens/fungi do?
absorb mineral and water while algae cells produce sugars by photosynthesis
